EMERGENCY MEDICINE

Dr. D. Cass, Dr. I. Dubinsky and Dr. M. Thompson Mark Freedman and Michael Klompas, editors Dana McKay, associate editor
INITIAL PATIENT ASSESSMENT . . . . . . . . . . . . . 2 AND MANAGEMENT Approach Prioritized Plan Rapid Primary Survey Airway Breathing Circulation Disability Exposure/Environment Resuscitation Detailed Secondary Survey Definitive Care PRE-HOSPITAL CARE. . . . . . . . . . . . . . . . . . . . . . . . 5 Level of Providers A PRACTICAL APPROACH TO. . . . . . . . . . . . . . . . 6 COMA AND STUPOR Glasgow Coma Scale Causes of Coma An ED Approach to Management of the Comatose Patient Basic Treatment of Herniation Syndromes TRAUMATOLOGY. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Epidemiology Documentation of Traumatic Injuries Shock Chest Trauma Immediately Life-Threatening Chest Injuries Potentially Life-Threatening Chest Injuries Abdominal Trauma Genitourinary Tract Injuries Head Trauma Spine and Spinal Cord Trauma Approach to Patient With a Suspected C-Spine Injury Pelivc and Extremity Injuries Soft Tissue Injuries Environmental Injuries Pediatric Trauma Considerations Trauma in Pregnancy AN APPROACH TO SELECTED. . . . . . . . . . . 26 COMMON ER PRESENTATIONS Analgesia Headache Chest Pain (Atraumatic) Anaphylaxis Alcoholic Emergencies Violent Patients Suicidal Patient Sexual Assault TOXICOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Approach to the Overdose Patient ABCs of Toxicology D1 - Universal Antidotes D2 - Draw Bloods D3 - Decontamination E - Examine the Patient Specific Toxidromes G - Give Specific Antidotes and Treatment Specific Antidotes and Treatments Specific Treatments pH Alteration Extra-Corporeal Drug Removal Disposition from the Emergency Department ACLS ALGORITHMS. . . . . . . . . . . . . . . . . . . . . 43 Ventricular Fibrillation/Ventricular Tachycardia Pulseless Electrical Activity Asystole Bradycardia Tachycardia

MCCQE 2000 Review Notes and Lecture Series

Emergency Medicine 1

INITIAL PATIENT ASSESSMENT AND MANAGEMENT

APPROACH
t patients are triaged as emergent urgent non-urgent 1. 2. 3. 4. Rapid Primary Survey (RPS) Resuscitation (often occurs at same time as RPS) Detailed Secondary Survey Definitive Care

Notes

PRIORITIZED PLAN

RAPID PRIMARY SURVEY

Airway maintenance with C-spine control Breathing and ventilation Circulation (pulses, hemorrhage control) Disability: neurologic status Exposure (complete) and environment (temperature control) t restart sequence from beginning if patient deteriorates

AIRWAY

t secure airway is first priority t assume a C-spine injury in every trauma patient > immobilize with collar and sand bags

Causes of Airway Obstruction t think of three areas airway lumen: foreign body, vomit airway wall: edema, fractures external to wall: lax muscles (tongue), direct trauma, expanding hematoma Airway Assessment t consider ability to breathe and speak to assess air entry t noisy breathing is obstructed breathing until proven otherwise t signs of obstruction apnea respiratory distress failure to speak dysphonia adventitous sounds cyanosis conduct (agitation, confusion, universal choking sign) t think about immediate patency and ability to maintain patency in future (decreasing LOC, increasing edema) t always need to reassess, can change rapidly Airway Management t goals achieve a reliably patent airway prevent aspiration permit adequate oxygenation and ventilation facilitate ongoing patient management give drugs via endotracheal tube NAVEL: narcan, atropine, ventolin, epinephrine, lidocaine t start with basic management techniques then progress to advanced Basic Management t protect the C-spine in the injured patient t chin lift or jaw thrust to open the airway t sweep and suction to clear mouth of foreign material t oral/nasopharyngeal airway

Emergency Medicine 2

MCCQE 2000 Review Notes and Lecture Series

INITIAL PATIENT ASSESSMENT AND MANAGEMENT . . . CONT.

Advanced Management t endotracheal intubation (see Figure 1) orotracheal +/ Rapid Sequence Intubation (RSI) nasotracheal - may be better tolerated in conscious patient does not provide 100% protection against aspiration t indications for intubation unable to protect airway inadequate spontaneous ventilation oxygen saturation < 90% with 100% oxygen profound shock GCS < or = 8 t surgical airway (if unable to intubate using oral/nasal route) needle (requires jet ventilator) cricothyroidotomy tracheotomy
trauma requiring intubation no immediate need C-spine x-ray positive fiberoptic ETT or nasal ETT or RSI unable cricothyroidotomy negative* oral ETT oral ETT apneic immediate need breathing facial smash oral ETT (no RSI) unable cricothyroidotomy no facial smash nasal ETT or RSI

Notes

unable cricothyroidotomy

* note: clearing the C-spine also requires clinical assessment (cannot rely on x-ray alone)

Figure 1. Approach to Endotracheal Intubation in an Injured Patient

BREATHING
LOOK

for mental status, chest movement, respiratory rate/effort, patients colour LISTEN for air escaping during exhalation, sounds of obstruction (e.g. stridor), auscultate for breath sounds and symmetry of air entry FEEL for the flow of air, chest wall for crepitus, flail segments and sucking chest wounds ASSESS tracheal position, neck veins, respiratory distress, auscultation of all lung fields

Oxygenation and Ventilation t measurement of respiratory function: rate, pulse oximetry, ABGs t treatment modalities nasal prongs > simple face mask > oxygen reservoir > CPAP/BiPAP to increase oxygen delivery venturi mask: used to precisely control oxygen delivery Bag-Valve mask and CPAP: to supplement ventilation

CIRCULATION (see Shock Section)

t check level of consciousness, skin colour, temperature, capillary refill t check the pulse for rate and rhythm patient may be unable to increase heart rate (e.g. use of -blockers, head injury, etc...)

MCCQE 2000 Review Notes and Lecture Series

Emergency Medicine 3

INITIAL PATIENT ASSESSMENT AND MANAGEMENT . . . CONT.

Table 1. Estimated Systolic Blood Pressure Based on Position of Palpable Pulse
Radial SBP > 80 Femoral > 70 Carotid > 60

Notes

t stop major external bleeding apply direct pressure elevate profusely bleeding extremities if no obvious unstable fracture consider pressure points (brachial, axillary, femoral) do not remove impaled objects as they tamponade bleeding use tourniquet as last resort

DISABILITY

t assess level of consciousness by AVPU method (quick, rudimentary assessment) A - ALERT V - responds to VERBAL stimuli P - responds to PAINFUL stimuli U - UNRESPONSIVE t size and reactivity of pupils t movement of upper and lower extremities t undress patient completely t essential to assess all areas for possible injury t keep patient warm with a blanket; avoid hypothermia t t t t t restoration of ABCs, oxygenation, ventilation, vital signs often done simultaneously with primary survey oxygen O2 saturation monitor gain IV access two large bore peripheral IVs for shock (14-16 guage) bolus with RL or NS (2 litres) and then blood as indicated for hypovolemic shock inotropes for cardiogenic shock vasopressors for septic shock vital signs - q 5-15 minutes ECG and BP monitors Foley and NG tube if indicated Foley contraindicated if blood from urethral meatus or other signs of urethral tear (see Traumatology section) NG tube contraindicated if significant mid-face trauma or basal skull fracture order appropriate tests and investigations: may include CBC, lytes, BUN, Cr, glucose, amylase, PT/PTT, -hCG, toxic screen (EtOH), Cross + Type

EXPOSURE / ENVIRONMENT

RESUSCITATION

t t t

DETAILED SECONDARY SURVEY

t done after Rapid Primary Survey problems have been corrected t designed to identify major injuries or areas of concern t involves history focused neurological exam head to toe physical exam X-rays (c-spine, chest, pelvis required in blunt trauma)

History t AMPLE: Allergies, Medications, Past medical history, Last meal, Events related to injury Neurological Examination t use GCS to detect changes in status (see Coma section) t breathing patterns alterations of rate and rhythm are signs of structural or metabolic abnormalities
Emergency Medicine 4 MCCQE 2000 Review Notes and Lecture Series

INITIAL PATIENT ASSESSMENT AND MANAGEMENT . . . CONT.

t progressive deterioration of breathing pattern implies a failing CNS pupils assess equality, size, symmetry, reactivity to light inequality suggests local eye problem or lateralizing CNS lesion reactivity/level of consciousness (LOC) reactive pupils + decreased LOC > metabolic or structural cause non-reactive pupils + decreased LOC> structural cause extra ocular movements and nystagmus fundoscopy (papilledema, hemorrhages) cranial nerve exam (including reflexes) assessment of spinal cord integrity conscious patient assess distal sensation and motor ability unconscious patient response to painful or noxious stimulus applied to extremities signs of increased ICP deteriorating LOC (hallmark of increasing ICP) deteriorating respiratory pattern Cushing reflex (high BP, slow heart rate) lateralizing CNS signs (e.g. cranial nerve palsies, hemiparesis) seizures papilledema (occurs late)

Notes

t t

Head To Toe Physical Exam t tubes and fingers in every orifice in injured patient t remember Medic-Alert tags, necklaces, bracelets, wallet card t look for specific toxidromes (see Toxicology Section) t head and neck examine for signs of trauma inspect for C-spine injuries (assume injury in head, face, and neck trauma) t complete examination of chest, abdomen, pelvis, perineum, and all four extremities t log roll for T and L spine exam in injured patient

DEFINITIVE CARE
1. 2. 3. 4.

continue therapy continue patient evaluations (special investigations) specialty consultations including O.R. disposition: home, admission, or another setting

PRE-HOSPITAL CARE
LEVEL OF PROVIDERS
t note: levels of providers not standard in every community t first responders usually non-medical (i.e. firefighters, police) administer CPR, O2, first aid, automatic defibrillation t basic Emergency Medical Attendant (EMA) basic airway management, O2 by mask or cannula, CPR, semi-automatic external defibrillation, basic trauma care t Level I Paramedic have symptom relief package: blood sugar levels, IM glucagon, and some drugs (nitro, Salbutamol, epinephrine, ASA) t Level II Paramedic start intravenous lines, blood sugar levels, interpret ECGs, manual defibrillation t Level III Paramedic advanced airway management, cardioversion and defibrillation, emergency drugs, ACLS, needle thoracostomy t base hospital physicians provide medical control and verbal orders for Paramedics through line patch ultimately responsible for delegated medical act and pronouncement of death in the field
Emergency Medicine 5

MCCQE 2000 Review Notes and Lecture Series

A PRACTICAL APPROACH TO COMA AND STUPOR

GLASGOW COMA SCALE (GCS)
t designed for use on trauma patients with decreased LOC; good indicator of severity of injury t often used for metabolic causes as well, but less meaningful t most useful if repeated changes in GCS with time is more relevant than the absolute number patient with deteriorating GCS needs immediate attention 4 3 2 1 5 4 3 2 1 6 5 4 3 2 1

Notes

Eyes Open spontaneously on command to pain no response Best Verbal Response answers questions appropriately confused, disoriented inappropriate words incomprehensible noise no verbal response Best Motor Response obeys commands localizes pain withdraws to pain decorticate (abnormal flexion) decerebrate (abnormal extension) no response

t best reported as a 3 part score: Eyes + Verbal + Motor = total t provides indication of degree of injury 13-15 = mild injury 9-12 = moderate injury less than or equal to 8 = severe injury t anyone with a severe injury needs an ETT t if patient intubated reported out of 10 + T (T= tubed, i.e. no verbal component)

CAUSES OF COMA
Definitions t Coma - a sleep-like state, unarousable to consciousness t Stupor - unresponsiveness from which the patient can be aroused t Lethargy - state of decreased awareness and mental status (patient may appear wakeful) Mechanisms t Structural Causes - 1/3 brainstem lesions that affect the RAS compression (e.g. supra/infratentorial tumour or subdural/epidural hematoma) direct damage (e.g. brainstem infarct, hemorrhage) cerebral diffuse cerebral cortical lesion diffuse trauma or ischemia t Metabolic/Toxic Causes - 2/3 M - major organ failure E - electrolyte/endocrine abnormalities T - toxins (e.g. alcohol, drugs, poisons) A - acid disorders B - base disorders O - decreased oxygen level L - lactate I - insulin (diabetes), ischemia, infection C - hypercalcemia
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A PRACTICAL APPROACH TO COMA AND STUPOR . . . CONT.

MANAGEMENT OF THE COMATOSE PATIENT
t ABCs t airway management should take into account probability of C-spine injury, high if: head or face trauma history of fall or collapse likelihood of aspiration adequacy of ventilation correct hypoxia and hypercarbia reversibility of the cause of the coma hypoglycemia or narcotic OD rapidly reversible therefore ETT may not be needed (controversial) need for maximizing oxygenation CO poisoning raised ICP (usually requires ETT)

Notes

Resuscitation Should Include t IV access t rapid blood sugar (finger prick) t glucose, CBC, lytes, Cr and BUN, LFT, and serum osmolality t ECG t arterial blood gases t universal antidotes thiamine 100 mg IM before glucose (if cachectic, alcoholic, malnourished) glucose 50 cc of 50% (D50W) if glucose < 4 mmol/L or rapid measurement not available naloxone 0.4-2.0 mg IV (opiate antagonist) if narcotic toxidrome present (risk of withdrawal reaction in chronic opiate users) t drug levels of specific toxins if indicated t rapid assessment and correction of abnormalities essential to prevent brain injury Secondary Survey and Definitive Care t focused history (from family, friends, police, EMA, etc...) aim to identify acute or insidious onset trauma or seizure activity medications, alcohol, or drugs past medical history (e.g. IDDM, depression) t physical examination (vital signs essential) with selected laboratory and imaging studies (x-ray and CT) Five Ns for inspection Noggin e.g. Raccoon eyes, Battles sign Neck C-spine, neurogenic shock, nuchal rigidity eNt otorrhea, rhinorrhea, tongue biting, odor on breath, and hemotympanum Needles track marks of IV drug abuse Neurological full examination essential but concentrate on GCS - follow over time respirations (rate and pattern) apneustic or ataxic (brainstem) Cheyne-Stokes (cortical) pupils - reactivity and symmetry (CN II, III) corneal reflex (CN V, VII) gag reflex (CN IX, X) oculocephalic reflex (after C-spine clearance) oculocaloric reflex (rule out tympanic perforation first) deep tendon reflexes and tone plantar reflex (positive Babinski if upgoing) t LP after normal CT to rule out meningitis, SAH

MCCQE 2000 Review Notes and Lecture Series

Emergency Medicine 7

A PRACTICAL APPROACH TO COMA AND STUPOR . . . CONT.

Diagnosis t findings suggesting a toxic-metabolic cause dysfunction at lower levels of the brainstem (e.g. caloric unresponsiveness) respiratory depression in association with an intact upper brainstem (e.g. reactive pupils) see Tables 2 and 3 Table 2. Structural vs. Metabolic Coma
Structural pupillary reaction extraocular movements motor findings asymmetric or absent asymmetric or absent asymmetric or absent Toxic-Metabolic pupils equal, round, regular reaction to light (see Table 3) symmetric or absent symmetric or absent

Notes

Table 3. Toxic - Metabolic Causes of Fixed Pupils

Cause anoxia Pupils dilated Characteristics antecedent history of shock, cardiac or respiratory arrest, etc... tachycardia, warm, dry skin Treatment 100% O2, expectant management physostigmine (for Atropine) sodium bicarbonate (for TCA)

anticholinergic agents (e.g. atropine, TCA's) cholinergic agents (e.g. organophosphates) opiates (e.g. heroin)

dilated

small, barely perceptible reflex pinpoint, barely perceptible reflex (exception: meperidine) normal or dilated midsized to dilated

diaphoresis, vomiting, incontinence, increased secretions needle marks

atropine

naloxone

hypothermia barbiturates

history of exposure temperature < 35C history of exposure positive serum levels confusion, drowsiness, ataxia shallow respirations and pulse optic neuritis increased osmolal gap metabolic acidosis

warm patient (e.g. warm IV solutions, blankets) ABCs no specific antidote

methanol (rare)

dilated

ethanol dialysis

Emergency Medicine 8

MCCQE 2000 Review Notes and Lecture Series

A PRACTICAL APPROACH TO COMA AND STUPOR . . . CONT.

t it is essential to re-examine comatose patients frequently - can change rapidly t diagnosis may only become apparent with the passage of time delayed deficit after head trauma suggestive of epidural hematoma Herniation Syndromes (see Neurosurgery Notes)

Notes

BASIC TREATMENT OF HERNIATION SYNDROMES

t t t t ABCs intubate and hyperventilate to a PCO2 of 30-35 mmHg mannitol (0.25-1 g/kg of 20% solution over 30 minutes) surgical decompression (where appropriate)

TRAUMATOLOGY
EPIDEMIOLOGY
t trauma is the leading cause of death in patients < 44 years t trimodal distribution of death minutes - lethal injuries - death usually at the scene golden hour - death within 4-6 hours - decreased mortality with trauma care days-weeks - death from multiple organ dysfunction, sepsis, etc... t injuries generally fall into two categories blunt - most common, due to MVC, falls, assault, sports, etc... penetrating - increasing in incidence - often due to gunshots, stabbings, impalements t to anticipate and suspect traumatic injuries it is important to know the mechanism of injury t always look for an underlying cause (seizure, suicide, medical problem)

DOCUMENTATION OF TRAUMATIC INJURIES

Motor Vehicle Collisions (MVC) t type of collision? velocity? t where was patient sitting? driver or passenger? other passenger injuries/fatalities? t passenger compartment intact? windshield? steering wheel? t seatbelt? airbag? t any loss of conciousness? how long? amnesia? t head injury? vomiting? headache? seizure? t use of alcohol? drugs? Falls t how far fell? how did patient land? t what surface did patient land on (dirt, cement)?

SHOCK (see Anesthesia Notes)

Definition: Inadequate Organ and Tissue Perfusion t think of perfusion to brain, kidney, extremities t look for depression in mental status, pallor, cool extremities, weak pulse t Classification S - Spinal (Neurogenic) and Septic H - Hypovolemic and Hemorrhagic O - Obstructive C - Cardiogenic K - Anaphylactic K
MCCQE 2000 Review Notes and Lecture Series Emergency Medicine 9

TRAUMATOLOGY . . . CONT.
t hemorrhagic shock (classic) - see Table 4 shock in the trauma patient is hemorrhagic until proven otherwise Table 4. Classification of Hemorrhagic Shock (for a 70kg male)
Class I II III IV Blood loss (mL) < 15% (< 750) 15-30% (750-1500) 30-40% (1500-2000) >40% (>2000) BP normal normal Pulse <100 >100 >120 >140 Resp rate 14-20 20-30 30-40 > 35 Urine output > 30 mL/hour 0-30 mL/hour 5-15 mL/hour 0 mL/hour

Notes

9 99

t cardiogenic shock myocardial contusion t obstructive shock (impaired venous return) tension pneumothorax, cardiac tamonade, pulmonary embolism t spinal/neurogenic shock (warm shock) spinal cord injuries (isolated head injuries do not cause shock) t septic shock suspect in febrile patient who arrives several hours after trauma look for bacteremia or nidus of infection t anaphylactic (see Anaphylaxis Section) Evaluation of Severity of Shock t vital signs t CNS status t skin perfusion t urine output t central venous pressure (CVP) line Blood Replacement if Needed t packed RBCs t cross-matched (ideal but takes time) t type specific t O-negative (children and women of child-bearing age) or O-positive (everyone else) if no time for cross and match t consider complications with massive transfusions Unproven or Harmful Treatments t Trendelenberg position t steroids (used only in spinal cord injury) t MAST garments - efficacy unknown t vasopressors during hemorrhagic shock

CHEST TRAUMA

t trauma to the chest accounts for, or contributes to 50% of trauma deaths t two types immediately life-threatening potentially life-threatening t identified and managed during the primary survey airway obstruction flail chest cardiac tamponade hemothorax pneumothorax (open, tension) t 80% of all chest injuries can be managed by non-surgeons with simple measures such as intubation, chest tubes, and pain control

IMMEDIATELY LIFE-THREATENING CHEST INJURIES

Tension Pneumothorax t a clinical diagnosis t one-way valve causes accumulation of air in the pleural space
Emergency Medicine 10 MCCQE 2000 Review Notes and Lecture Series

TRAUMATOLOGY . . . CONT.
t decreased venous return (torsion/compression of large venous vessels) + impaired function of good lung = HYPOXIA t inspection: respiratory distress, tachycardia, distended neck veins, cyanosis, asymmetry of chest wall motion t palpation: tracheal deviation away from pneumothorax t percussion: hyperresonnance t auscultation: unilateral absence of breath sounds, hypotension t management large bore needle, 2nd intercostal space, mid-clavicular line followed by chest tube in 5th intercostal space, anterior axillary line Open Pneumothorax t gunshot or open wound to chest, if hole is > 2/3 tracheal diameter air will preferentially enter chest from wound rather than trachea t lung collapse > ineffective ventilation > HYPOXIA t check posterior wall for exit wound t management cover wound with air-tight dressing sealed on 3 sides insert chest tube definitive care (surgery) Massive Hemothorax t > 1500 mL blood loss in chest cavity t inspection: pallor, flat neck veins, shock t percussion: unilateral dullness t auscultation: absent breath sounds, hypotension t management restore blood volume (rapid crystalloid infusion) decompress with chest tube indications for thoracotomy > 1500 cc total blood drained from chest tube > 200 cc/hour continued drainage Flail Chest t free-floating segment of chest wall t multiple rib fractures (> 4), each fractured at two sites t underlying lung contusion causes most of the problem, not fractures t lung injury (poor compliance > V/Q mismatch > HYPOXIA) t increased work of breathing > FATIGUE t inspection: respiratory distress, cyanosis, paradoxical movement of flail segment t palpation: crepitus of ribs t auscultation: decreased air entry on affected side t ABGs: decreased pO2, increased pCO2 t CXR: rib fractures, lung contusion t management O2 + fluid therapy + pain control positive pressure ventilation intubation and ventilation may be necessary Cardiac Tamponade t usually from penetrating injury t 15-20 cc of blood in pericardium sufficient to interfere with cardiac activity t Becks classic triad hypotension (with pulsus paradoxus) distended neck veins muffled heart sounds (with tachycardia) t investigation: Echo t management IV fluids pericardiocentesis open thoracotomy

Notes

MCCQE 2000 Review Notes and Lecture Series

Emergency Medicine 11

TRAUMATOLOGY . . . CONT.
POTENTIALLY LIFE-THREATENING CHEST INJURIES
t identified in secondary survey (CXR) C - Contusion: pulmonary, myocardial, aortic H - Hernia: traumatic diaphragmatic ES - ESophageal perforation T - Tracheobronchial disruption/Tear (aortic) t with these injuries - need to have high index of suspicion, usually dependent on mechanism of injury

Notes

Pulmonary Contusion t history: blunt trauma to chest t interstitial edema impairs compliance and gas exchange t CXR: areas of opacification of lung within 6 hours of trauma t management maintain adequate ventilation monitor with ABG, pulse oximeter and ECG chest physiotherapy positive pressure ventilation if severe Myocardial Contusion t history: blunt trauma to chest (usually in setting of multi-system trauma and therefore difficult to diagnose) t physical examination: overlying injury, i.e. fractures, chest wall contusion t investigations ECG: arrhythmias, ST changes serial CK-MB cardiac output monitoring 2D ECHO radionuclide (MUGA) scan t management oxygen antiarrhythmic agents analgesia Ruptured Diaphragm t more often diagnosed on left side since liver conceals defect on right t history: blunt trauma to chest or abdomen (high lap belt in MVC) t investigations CXR - abnormality of diaphragm/lower lung fields/NG tube placement t management laparotomy because of associated intra-abdominal injuries Esophageal Injury t history: penetrating trauma t investigations CXR: mediastinal air (not always) esophagram (Gastrograffin) flexible esophagoscopy t management repair (if in first 24 hours) Tracheobronchial Injuries t larynx history: strangulation, clothes line, direct blow, blunt trauma, any penetrating injury involving platysma triad of hoarseness subcutaneous emphysema palpable fracture, crepitus other symptoms: hemoptysis, dyspnea

Emergency Medicine 12

MCCQE 2000 Review Notes and Lecture Series

TRAUMATOLOGY . . . CONT.
investigations CXR CT scan arteriography (if penetrating) management airway - manage early because of edema C-spine: may also be injured, consider mechanism of injury surgical tracheotomy versus repair surgical exploration if deep to platysma (penetrating) DONT clamp structures (can damage nerves) probe insert NG tube (leads to bleeding) remove weapon/impaled object t trachea/bronchus frequently missed history: deceleration, penetration, increased intra-thoracic pressure complaints of dyspnea, hemoptysis examination: subcutaneous air, Hammans sign (crunching sound synchronous with heart beat) CXR: mediastinal air, persistent pneumothorax management surgical repair if > 1/3 circumference Aortic Tear t 90% tear at subclavian, most die at scene t salvageable if diagnosis made rapidly in ED t history sudden high speed deceleration (e.g. MVC, falls, airplane crash) complaints of chest pain, dyspnea, hoarseness t physical examination: decreased femoral pulses, differential arm BP (arch tear) t investigations: CXR, aortogram, CT scan t x-ray features include wide mediastinum (most consistent) pleural cap massive left hemothorax indistinct aortic knuckle tracheal deviation to right side depressed left mainstem bronchus esophagus (NG tube) deviated to right side t management thoracotomy (may treat other severe injuries first) Late Causes of Death in Chest Trauma respiratory failure sepsis (adult respiratory distress syndrome)

Notes

ABDOMINAL TRAUMA

t two mechanisms blunt trauma - usually causes solid organ injury penetrating trauma - usually causes hollow organ injury

Blunt Trauma t two types intra-abdominal bleed retroperitoneal bleed t high clinical suspicion in multi-system trauma t physical exam unreliable in multi-system trauma slow blood loss not immediately apparent other injuries may mask symptoms serial examinations are required t inspection: contusions, abrasions, distension, guarding t palpation: tenderness, point of maximal tenderness, rebound tenderness, rigidity
MCCQE 2000 Review Notes and Lecture Series Emergency Medicine 13

TRAUMATOLOGY . . . CONT.
t diagnostic tests are indicated in patients with unexplained shock equivocal signs of abdominal injury unreliable physical exam (paraplegia, head injury, substance use) high likelihood of injury (pelvic/lumbar fracture, etc...) impending periods of non-observation (e.g. surgery) t diagnostic tests include flat plate for retroperitoneal air or blood (psoas shadow obliterated) CXR free air under diaphragm diaphragmatic herniation ultrasound: pelvis, spleen, liver CT scan IVP diagnostic peritoneal lavage (DPL) tests for intra-peritoneal bleed cannot test for retroperitoneal bleed discerning lethal from trivial bleed diaphragmatic rupture criteria for positive lavage: > 10 cc gross blood bile, bacteria, foreign material RBC count > 100 000 x 106/L, WBC > 500 x 106/L, amylase > 175 IU t management general: fluid resuscitation and stabilization surgical: watchful wait versus laparotomy t note: seatbelt injuries may have retroperitoneal duodenal trauma intraperitoneal bowel transection mesenteric injury L-spine injury Penetrating Trauma t high risk of GI perforation and sepsis t history: size of blade, calibre/distance from gun, route of entry t local wound exploration with the following exceptions: thoracoabdominal region (may cause pneumothorax) back or flanks (muscles too thick) t management gunshot wounds > always require laparotomy stab wounds - Rule of thirds 1/3 do not penetrate peritoneal cavity 1/3 penetrate but are harmless 1/3 cause injury requiring surgery mandatory laparotomy if shock peritonitis evisceration free air in abdomen blood in NG tube, Foley catheter or on rectal exam

Notes

GENITOURINARY TRACT INJURIES

t diagnosis based on mechanism of injury, hematuria (gross or microscopic, but may be absent), and appropriate radiological studies

Renal Trauma t etiology blunt trauma contusions (parenchymal ecchymosis with intact renal capsule) parenchymal tears non-communicating (hematoma) communicating (urine extravasation, hematuria)
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TRAUMATOLOGY . . . CONT.
t t t penetrating injuries renal pedicle injury due to acceleration/deceleration history: mechanism of injury, hematuria, flank pain physical exam: CVA tenderness, upper quadrant mass, shock investigations CT scan (study of choice if hemodynamically stable) IVP (during laparotomy) renal arteriography (if renal artery injury suspected) management 90% conservative (bedrest, analgesia, antibiotics) 10% surgical for hemodynamically unstable or continuing to bleed > 48 hours major urine extravasation renal pedicle injury all penetrating wounds major lacerations renal artery thrombosis infection

Notes

Ureter t etiology blunt (rare) at uretero-pelvic junction penetrating (rare) iatrogenic (most common) t history: mechanism of injury, hematuria t physical exam: findings related to intra-abdominal injuries t investigations: retrograde ureterogram t management: uretero-uretostomy Bladder t etiology blunt trauma extraperitoneal rupture from pelvic fracture fragments intraperitoneal rupture from trauma + full bladder penetrating trauma t history: gross hematuria, dysuria, urinary retention, abdominal pain t physical exam extraperitoneal rupture: pelvic instability, suprapubic tenderness from mass of urine or extravasated blood intraperitoneal rupture: acute abdomen t investigations: urinalysis, plain abdominal film, CT scan, urethrogram, +/ retrograde cystography t management extraperitoneal: minor rupture > Foley drainage, major rupture > surgical repair intraperitoneal: drain abdomen and surgical repair Urethral t etiology usually blunt trauma in men anterior (bulbous) urethra damage with straddle injuries posterior (bulbo-membranous) urethra with pelvic fractures t history/physical anterior: blood at meatus, perineal/scrotal hematoma, blood and urine extending from penile shaft and perineum to abdominal wall posterior: inability to void, blood at meatus, suprapubic tenderness, pelvic instability, superior displacement of prostate, pelvic hematoma on rectal exam t investigation: retrograde urethrography t management anterior: if Foley does not pass, requires suprapubic drain posterior: suprapubic drainage, avoid catheterization

MCCQE 2000 Review Notes and Lecture Series

Emergency Medicine 15

TRAUMATOLOGY . . . CONT.
HEAD TRAUMA
t t t t 60% of trauma admissions have head injuries 60% of MVC-related deaths are due to head injury first physician who sees patient has greatest impact on the outcome alteration of consciousness is the hallmark of brain injury

Notes

Assessment of Brain Injury t history pre-hospital state, mechanism of injury t vital signs shock Cushings response to increasing ICP (bradycardia with hypertension) hyperthermia t level of consciousness Glasgow Coma Scale t pupils: pathology = anisocoria > 1 mm (in patient with altered LOC) t neurological exam: lateralizing signs - motor/sensory Severe Head Injury t GCS < or = 8 t deteriorating GCS t unequal pupils t lateralizing signs Investigations t CT scan t skull x-rays little value in the early management of obvious blunt head injury for diagnosis of calvarium fractures (not brain injury) clinical diagnosis superior for basal skull fractures (i.e. raccoon eyes, Battles Sign, hemotympanum, CSF otorrhea / rhinorrhea) may help localize foreign body after penetrating head injury Specific Injuries t skull fractures linear, non-depressed linear, depressed open basal skull t diffuse brain injury concussion (brief LOC then normal) diffuse axonal injury t focal injuries contusions intracranial hemorrhage epidural acute subdural intracerebral Management t general ABCs treat other injuries i.e. shock, hypoxia, spinal t medical seizure treatment/prophylaxis steroids are of NO proven value diazepam, phenytoin, phenobarbital treat suspected raised ICP 100% O2 intubate and hyperventilate to a pCO2 of 30-35 mmHg mannitol 1 g/kg infused as rapidly as possible raise head of stretcher 20 degrees if patient hemodynamically stable consider paralyzing meds if agitated/high airway pressures t surgical neurosurgical consultation Emergency Medicine 16 MCCQE 2000 Review Notes and Lecture Series

TRAUMATOLOGY . . . CONT.
SPINE AND SPINAL CORD TRAUMA
t spinal immobilization (cervical collar, spine board) must be maintained until spinal injury has been ruled out t vertebral injuries may be present without spinal cord injury, therefore normal neurologic exam does not exclude spinal injury t if a fracture is found, be suspicious, look for another fracture t spine may be unstable despite normal C-spine x-ray t collar everyone except those that meet ALL the following criteria no pain no tenderness no neurological symptoms or findings no significant distracting injuries no head injury no intoxication t note: patients with penetrating trauma (especially gunshot and knife wounds) can also have spinal cord injury

Notes

X-Rays t full spine series for trauma AP, lateral, odontoid t lateral C-Spine must be obtained on all blunt trauma patients (except those meeting above criteria) must visualize C7-T1 junction (Swimmers view often required) t thoracolumbar AP and lateral views indicated in patients with C-spine injury unconscious patients patients with symptoms or neurological findings Management of Cord Injury t immobilize the entire spine with the patient in the supine position (collar, sand bags, padded board, straps) t if patient must be moved, use a log roll technique with assistance t if cervical cord lesion, watch for respiratory insufficiency low cervical transection (C5-T1) produces abdominal breathing (phrenic innervation of diaphragm still intact) high cervical cord injury > no breathing > intubation t hypotension (neurogenic shock) treatment: warm blanket, Trendelenberg position (occasionally), volume infusion, consider vasopressors t methylprednisolone within 8 hours of injury (30 mg/kg initially followed by 5.4 mg/kg per hour for 23 hours)

APPROACH TO PATIENT WITH SUSPECTED C-SPINE INJURY

Clearing the C-Spine t negative clinical exam t normal x-rays Indications for X-rays t altered mental status t history midline neck pain: recheck for pain on movement after palpation past history of spinal mobility disorder (ankylosing spondylitis, rheumatoid arthritis, osteoarthritis, vertebral fusion) t physical exam posterior neck tenderness, spasm, or crepitus any neurologic signs of deficits: tone, power, reflexes, sensation, autonomic dysfunction (rectal tone, priapism) other painful distracting injuries t x-ray all unconscious trauma patients
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TRAUMATOLOGY . . . CONT.
C-Spine X-Rays t The 3-view C-spine series is the screening modality of choice AP lateral C1-T1 ( swimmers view) - T2 not involved with neck movements odontoid (open mouth or oblique submental view) t supine obliques can detect some injuries not seen on 3-views better visualization of posterior element fractures (lamina, pedicle, facet joint) can be used to visualize the cervicothoracic junction Lateral View: The ABCS A - Alignment and Adequacy t Must see C1 to C7-T1 junction - if not - downward traction of shoulders, swimmers view, bilateral supine obliques, or CT scan t lines of contour (see Figure 2) (NB in children < 8 years of age: physiologic subluxation of C2 on C3, and C3 on C4, but the spinolaminal line is maintained) t widening of interspinous space (fanning of spinous processes) suggests posterior ligamentous disruption t widening of facet joints t check atlanto-occipital joint: line extended inferiorly from clivus should transect odontoid t atlanto-axial articulation - widening of predental space (> 3 mm in adults, > 5 mm in children) B - Bones t height, width and shape of each vertebral body t pedicles, facets, and laminae should appear as one - doubling suggests rotation C - Cartilages t intervetebral disc spaces - widening anteriorly or posteriorly suggests vertebral compression S - Soft Tissues t widening of retropharyngeal (> 7 mm at C1-4, may be wide in children less than 2yo on expiration) or retrotracheal spaces (> 22 mm at C6-T1, > 14 mm in children < 15 years of age) t prevertebral soft tissue swelling: only 49% sensitive for injury Odontoid View t rule out rotation and fracture t odontoid should be centred between C1 lateral masses t lateral masses of C1 and C2 should be perfectly aligned laterally t lateral masses should be symmetrical (equal size) Anteroposterior View t alignment of spinous processes in the midline t spacing of spinous processes should be equal t check vertebral bodies Indications for CT Scan t inadequate plain film survey t suspicious plain film findings t to better delineate injuries seen on plain films t any clinical suspicion of atlanto-occipital dislocation t high clinical suspicion of injury despite normal plain films t include C1-C3 when head CT is indicated in head trauma cases

Notes

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TRAUMATOLOGY . . . CONT.

Notes

5 4 3 1 1. anterior vertebral line 2. posterior vertebral line (anterior margin of spinal canal) 3. posterior border of facets 4. laminar fusion line (posterior margin of spinal canal) 5. posterior spinous line (along tips of spinous processes) Figure 2. Lines of Contour on a Lateral C-Spine X-Ray
Drawing by Kim Auchinachie

Management Considerations t immobilize C-spine with collar and sand bags (collar alone is not enough) t injuries above C4 may need ventilation t continually reassess high cord injuries - edema can travel up cord t beware of neurogenic shock t administer methylprednisolone within 8 hours of C-spine injury t turn patient q2h to prevent decubitus ulcers t clear C-spine and remove from board ASAP to prevent ulcers t before O.R. ensure thoracic and lumbar x-rays are normal, since 20% of patients with C-spine fractures have other spinal fractures Sequelae of C-spine Fracture t decreased descending sympathetic tone (neurogenic / spinal shock) responsible for most sequelae t cardiac no autoregulation, falling BP, decreasing HR, vasodilation GIVE IV FLUIDS pressors t respiratory no cough reflex (risk of aspiration pneumonia) no intercostal muscles +/ diaphragm intubate and maintain vital capacity t GI ileus, vasodilation, bile and pancreatic secretion continues (> 1L/day), risk of aspiration, GI stress ulcers NG tube may be required for suctioning, feeding, etc... t renal hypoperfusion > IV fluids kidney still producing urine (bladder can rupture if patient not urinating Foley catheter may be required (measure urine output/perfusion) t skin vasodilation, heat loss, no thermoregulation, atrophy (risk of skin ulcers) t muscle flaccidity, atrophy, decreased venous return t penis priapism
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TRAUMATOLOGY . . . CONT.
PELVIC AND EXTREMITY INJURIES
t rarely life threatening, often limb threatening t evaluation carried out in secondary survey t patient must be completely undressed for evaluation

Notes

Physical Exam t Look: deformity, swelling, bleeding, bruising, spasm, colour t Feel: pulse, warmth, tenderness, crepitation, sensation, capillary refill t Movement: ROM assessed actively (beware passive ROM testing) Life Threatening Injuries t major pelvic fractures t traumatic amputations t massive long bone fractures (e.g. femoral) t vascular injuries proximal to knee/elbow Limb Threatening Injuries t fracture/dislocation of ankle t crush injuries t compartment syndrome t dislocations of knee/hip t fractures with vascular/nerve injury t open fractures t fractures above the elbow or knee Blood Loss t may be major in pelvic fractures (up to 3.0 litres blood lost) femur fractures (up to 2.0 litres blood lost per femur) open fractures (double blood loss of a closed fracture) Assessment of Neurovascular Injury t assess pulses before and after immobilization t diminished pulses should not be attributed to spasm t angiography is definitive if diagnosis in doubt Vascular Injuries Suggested by 5 Ps t pulse discrepancies t pallor t paresthesia/hypoesthesia (loss of sensation first sign of ischemia) t paresis t pain (especially when refractory to usual doses of analgesics) Treatment of Vascular Compromise t realign limb/apply traction t recheck pulses (Dopplers) t surgical consult t consider measuring compartment pressures t angiography Compartment Syndrome t rise in interstitial pressure above that of capillary bed (30-40 mmHg) t usually in leg or forearm t often associated with crush injuries (extensive soft tissue damage) t diagnosed by measurement of compartment pressures t suspect when you find excessive pain with passive stretching of involved muscles decreased sensation of nerves in that compartment tense swelling weakness, paralysis t pulse may still be present until very late
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TRAUMATOLOGY . . . CONT.
Management of Extremity Injuries t fractures immobilize/traction t open wounds remove gross contamination, irrigate cover with sterile dressing definitive care within 6-8 hours control bleeding with pressure (no clamping) splint fracture antibiotics - cefazolin (+/ gentamicin/metronidazole in extensive/dirty injury) tetanus prophylaxis t joint injuries orthopedic consultation reduce dislocations after x-ray immobilize t compartment syndrome remove constrictive dressings/casts prompt fasciotomy

Notes

SOFT TISSUE INJURIES

Bruises t tender swelling (hematoma) following blunt trauma t is patient on anticoagulants? coagulopathy? t acute treatment R - rest I - ice C - compression E - elevation Abrasions t partial to full thickness break in skin t management clean thoroughly (under local anesthetic if necessary) with brush to prevent foreign body impregnation (tattooing) antiseptic ointment (Polysporin) or vaseline for 7 days for facial and complex abrasions Lacerations t always consider every structure deep to a laceration severed until proven otherwise t never test function against resistance t physical exam think about underlying anatomy examine tendon function and neurovascular status distally x-ray wounds if a foreign body is suspected (e.g. shattered glass) and not found when exploring wound clean and explore under local anesthetic t management irrigate copiously with normal saline evacuate hematomas, debride non-viable tissue, and remove foreign bodies secure hemostasis suture (Steristrip, glue, or staple for selected wounds) unless delayed presentation, a puncture wound, or animal bite in general, facial sutures are removed in 5 days, those over joints in 10 days, and everywhere else in 7 days in children, topical anesthetics such as TAC (tetracaine, adrenaline and cocaine) and in selected cases a short acting benzodiazepine (midazolam) for sedation and amnesia are useful DO NOT use local anesthetic with epinephrine on fingers, toes, penis, ears, nose maximum dose of lidocaine 7 mg /kg with epinephrine 5 mg /kg without epinephrine
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TRAUMATOLOGY . . . CONT.
Mammalian Bites t important points on history: time and circumstances of bite allergies symptoms tetanus comorbid conditions rabies risks t on examination assess type of wound: abrasion, laceration, puncture, crush injury assess for direct tissue damage - skin, bone, tendon, neurovascular t x-rays if bony injury or infection suspected check for gas in tissue ALWAYS get skull films in children with scalp bite wounds, +/ CT to rule out cranial perforation t treatment wound cleansing and copious irrigation as soon as possible irrigate/debride puncture wounds if feasible, but not if sealed or very small openings - avoid hydrodissection along tissue planes debridement is important in crush injuries to reduce infection and optimize cosmetic and functional repair culture wound if signs of infection (erythema, necrosis or pus) - anaerobic cultures if foul smelling, necrotizing, or abscess notify lab that sample is from bite wound t most common complication of mammalian bites is infection (2 to 50%) types of infections resulting from bites: cellulitis, lymphangitis, abscesses, tenosynovitis, osteomyelitis, septic arthritis, sepsis, endocarditis, meningitis early wound irrigation and debridement are the most important factors in decreasing infection t to suture or not to suture? the risk of wound infection is related to vascularity of tissue vascular structures (i.e. face and scalp) are less likely to get infected, therefore suture avascular structures (i.e. pretibial regions, hands and feet) by secondary repair t high risk factors for infection puncture wounds crush injuries wounds greater than 12 hours old hand or foot wounds, wounds near joints immunocompromised patient patient age greater than 50 years prosthetic joints or valves Tetanus Prophylaxis t clean wounds management tetanus status unknown or never vaccinated > full course tetanus toxoid last tetanus > 10 years > booster last tetanus < 10 years > nothing t dirty wounds management tetanus status unknown or never vaccinated: > tetanus Ig (human) + full course tetanus toxoid last tetanus > 10 years > booster last tetanus < 10 years > nothing Prophylactic antibiotics t widely recommended for all bite wounds to the hand t should be strongly considered for all other high-risk bite wounds t 3-5 days is usually recommended for prophylactic therapy t dog and cat bites (pathogens: Pasteurella multocide, S. aureus, S. viridans) 1st line: Clavulin 2nd line: tetracycline or doxycycline 3rd line: erythromycin, clarithromycin, azithromycin
Emergency Medicine 22

Notes

MCCQE 2000 Review Notes and Lecture Series

TRAUMATOLOGY . . . CONT.
t human bites (pathogens: Eikenella carrodens, S. aureus, S. viridans, oral anaerobes) 1st line: Clavulin 2nd line: erythromycin, clarithromycin, azithromycin 3rd line: clindamycin

Notes

ENVIRONMENTAL INJURIES
Burns (see Plastic Surgery Notes) t immediate management remove noxious agent resuscitation Ringer's lactate: 4cc/kg/%BSA burned (not including 1st degree) according to Parkland formula (1/2 in first 8 hours, 1/2 in second 16 hours) at 8 hours, fresh frozen plasma or 5% albumin: if > 25% BSA give 3-4 U/day for 48 hours second 8 hours, 2/3-1/3 at 2cc/kg/%BSA urine output should be 40-50 cc/hr or 0.5 cc/kg/hr avoid diuretics continuous morphine infusion at 2 mg/hr with rescue bolus burn wound care escharotomy or fasciotomy for circumferential burns (chest, extremities) cover gently with sterile dressings systemic antibiotics infrequently indicated topical - silver sulfadiazene; face - polysporin; ears sulfomyalon t guidelines for hospitalization 10-50 years old with 2nd degree burns to > 15% TBSA or 3rd degree to greater than 5% TBSA less than 10 years old or > 50 years old with 2nd degree to > 10% TBSA or 3rd degree to > 3% TBSA 2nd or 3rd degree on face, hands, feet, perineum or across major joints electrical or chemical burns burns with inhalation injury burn victims with underlying medical problems or immunosuppressed patients (e.g. DM, cancer, AIDS, alcoholism) Inhalation Injury t CO poisoning closed environment cherry red skin/blood (usually a post-mortem finding) headache, nausea, confusion pO2 normal but O2 sat low measure carboxyhemoglobin levels treatment: 100% O2 +/ hyperbaric O2 t thermal airway injury etiology: injury to endothelial cells and bronchial cilia due to fire in enclosed space symptoms and signs: facial burns, intraoral burns, singed nasal hairs, soot in mouth/nose, hoarseness, carbonaceous sputum, wheezing investigations: CXR +/ bronchoscopy treatment: humidified oxygen, early intubation, pulmonary toilet, bronchodilators Hypothermia t predisposing factors: old age, lack of housing, drug overdose, EtOH ingestion, trauma (incapacitating), cold water immersion, outdoor sports t diagnosis: mental confusion, impaired gait, lethargy, combativeness, shivering t treatment on scene remove wet clothing; blankets + hot water bottles; heated O2, warmed IV fluids no EtOH due to peripheral vasodilating effect
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TRAUMATOLOGY . . . CONT.
vitals (take for > 1 minute) cardiac monitoring; no chest compressions until certain patient pulseless > 1 minute, since can precipitate ventricular fibrillation NS IV since patient is hypovolemic and dehydrated secondary to cold water diuresis and fluid shifts note: if body temperature < 32.2C, you may see decreased heart rate, respiratory rate, and muscle tone, dilated + fixed pupils (i.e. patient appears dead) due to decreased O2 demands, patient may recover without sequelae t treatment in hospital patient hypovolemic and acidotic rewarm slowly with warm top + bottom blankets (risk of afterdrop if cold acidotic blood of periphery recirculated into core) at body temperature < 30C risk of ventricular fibrillation therefore warm via peritoneal/hemodialysis or cardiopulmonary bypass t PATIENT IS NOT DEAD UNTIL THEY ARE WARM AND DEAD! Frostbite t classified according to depth - similar to burns (1st to 3rd degree) t 1st degree symptoms: initial paresthesia, pruritis signs: erythema, edema, hyperemia, NO blisters t 2nd degree symptoms: numbness signs: blistering, erythema, edema t 3rd degree symptoms: pain, burning, throbbing (on thawing) signs: hemorrhagic blisters, skin necrosis, edema, decreased range of motion t management remove wet and constrictive clothing immerse in 40-42C water for 10-30 minutes elevate, wrap individual appendages in dry gauze tetanus prophylaxis ASA local anti-infective prophylactic IV antibiotics for deep frostbite surgical amputation/debridement in 3-6 weeks if no recovery never allow a thawed area to re-freeze

Notes

PEDIATRIC TRAUMA CONSIDERATIONS

t priorities remain the same Airway t sniffing position t short trachea (5 cm in infants, 7.5 cm at 18 months) t orotracheal tube diameter = age/4 + 4 t uncuffed ETT under age 8 t surgical cricothyroidotomy NOT indicated t needle cricothyroidectomy with jet ventilation if unable to intubate Breathing t stethoscope not as useful for diagnosing problems - noting tachypnea is important Circulation t normal blood volume = 80 ml/kg t fluid resuscitation bolus crystalloid 20 ml/kg repeat x 1 if necessary blood replacement if no response to 2nd bolus of crystalloid
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TRAUMATOLOGY . . . CONT.
t venous access intraosseous infusion if unable to establish IV access in < 30 seconds venous cutdown (medial cephalic, external jugular, great saphenous) Thermoregulation t children prone to hypothermia t blankets/external warming/cover scalp Table 5. Normal Vitals in Pediatric Patients
P infant preschool adolescent < 160 < 140 < 120 sBP 80 90 100 RR 40 30 20

Notes

TRAUMA IN PREGNANCY

t treatment priorities the same t the best treatment for the fetus is to treat the mother

Hemodynamic Considerations t near term, inferior vena caval compression in the supine position can decrease cardiac output by 30-40% use left lateral decubitus positioning to alleviate compression and increase blood return t BP drops 5-15 systolic in 2nd trimester, increases to normal by term t HR increases 15-20 beats by 3rd trimester Blood Considerations t physiologic macrocytic anemia of pregnancy (Hb 100-120) t WBC increases to high of 20 000 Shock t pregnant patients may lose 35% of blood volume without usual signs of shock (tachycardia, hypotension) t however, the fetus may be in shock due to contraction of the uteroplacental circulation Management Differences t place bolster under right hip to stop inferior vena cava compression t fetal monitoring (Doppler) t early obstetrical involvement t dont avoid x-rays (C-spine, CXR, pelvis)

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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS

ANALGESIA
Table 6. Analgesics Indicated for Specific Presentations (Adults)
Injury severe trauma, burns, visceral pain, perforation, myocardial infaction, biliary/renal colic, pancreatitis renal colic gout soft tissue injuries, dysmenorrhea earache/sore throat dental herpes zoster, trigeminal neuralgia Drug morphine* demerol Dose 2-10 mg 12.5-25 mg Route IV IV Notes

Notes

titrate doses to effect

indomethacin indomethacin NSAID acetaminophen codeine and/or codeine and/or carbamazepine

100 mg 25-100 mg TID

PR PO PO

may decrease narcotic need start high dose and taper over 5-7 days

10-15 mg/kg q4h 1 mg/kg 1 mg/kg 100 mg BID

PO PO

antipyretic/ analgesic NSAID

PO PO

titrate up

*may need Gravol 25-50 mg IV for nausea when using opiod analgesics

HEADACHE

t key principles brain is anesthetic ( most headaches arise from surrounding structures such as blood vessels, periosteum, muscle) every headache is serious until proven otherwise t serious causes increased ICP due to mass lesions (abscess, subdural, brain tumour) intracranial bleeding from subarachnoid or intracerebral hemorrhage meningitis (bacterial or viral) temporal arteritis and other vasculitides t common types common migraine (no aura) classic migraine (involves aura) tension headache cluster headache t clinical danger signs worst headache ever or change in quality of previous headache sudden onset decreased level of consciousness history of trauma new onset in person over age 50 or under age 10 persistent nausea / vomiting symptoms persisting over days and weeks meningeal irritation (Kernigs Sign, Brudzinskis Sign) abnormal vital signs (including fever) focal neurological signs pupillary abnormality t investigations CT scan (low sensitivity for meningitis but 95% sensitive for subarachnoid bleeds) LP to rule out bleed or meningitis if CT negative
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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS . . . CONT.

CHEST PAIN (ATRAUMATIC)
Must Rule Out Life-Threatening Causes t unstable angina/acute MI t thoracic aortic dissection t pulmonary embolism t spontaneous pneumothorax ( tension) t esophageal rupture t pericarditis / cardiac tamponade Additional Differential Diagnosis t stable angina t GI disorders: PUD, pancreatitis, cholecystitis, esophagitis, etc t pneumonia t MSK t psychogenic History t compare with previous episodes t description of pain t deep visceral vs. superficial somatic t classic presentations (remember, presentations are seldom classic) aortic dissection - sudden severe tearing pain, often radiating to back pulmonary embolism - pleuritic chest pain (75%), dyspnea, anxiety pericarditis - anterior precordial pain, pleuritic, relieved by sitting up and leaning forward acute CAD - retrosternal squeezing/pressure pain, radiation to arm/neck, dyspnea, nausea/vomiting, syncope t consider esophageal etiology with the following: frequent heartburn acid reflux dysphagia relief with antacids t associated symptoms t risk factors for CAD, PE t more likely to be atypical in females, and people > 80-years-old Physical Exam t vitals tachypnea (may be only sign of PE) BP in BOTH arms > 20 mmHg difference suggests thoracic aortic dissection t palpate chest wall for tender points but not a good discriminator since 25% of patients with acute MI have chest wall tenderness accept only if fully reproduces pain symptoms, and more serious causes excluded may result from pleural inflammation t cardiac exam friction rub new murmurs mitral regurgitation murmur in acute MI (papillary muscle dysfunction) aortic insufficiency murmur in aortic dissection t respiratory exam percuss and auscultate all the lung fields t peripheral vascular exam - abdomen, extremities Investigations t ECG cardiac + non-cardiac causes (PE) PE, acute MI may have NORMAL ECG! always compare with previous

Notes

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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS . . . CONT.

t CXR pulmonary embolism often completely NORMAL atelectasis, elevated hemidiaphragm, Westermarks sign, Hamptons hump aortic dissection mediastinal widening, bulging aortic arch, pleural effusion, separation of intimal calcification from edge of aortic shadow t ABGs - NORMAL in 20% of patients with PE t serial cardiac enzymes (see Cardiology Section) normal CK does NOT rule out MI elevated CK is MI until proven otherwise newer markers (e.g. troponin I) increase accuracy t V/Q scan if suspicion of PE

Notes

ANAPHYLAXIS

t anaphylactic: IgE mediated, requires sensitization, time lag, and reexposure (e.g. food, vaccines, antibiotics) t anaphylactoid: non-IgE mediated, direct trigger, may occur with first exposure (e.g. radiocontrast dyes, ASA, NSAIDS) t symptoms and signs cardiovascular collapse (shock) marked anxiety and apprehension generalized urticaria, edema, erythema, light-headedness choking sensation, cough, bronchospasm or laryngeal edema abdominal pain, nausea, vomiting, diarrhea t allergies and prior episodes important t severe cases: hypotension and loss of consciousness incontinence sudden death t treatment stop the cause secure airway and obtain IV access on scene - epi-pen (injectable epinephrine) if available if signs and symptoms are MODERATE (minimal airway edema, mild bronchospasm, cutaneous reactions) treat with adult 0.3 -0.5 ml of 1:1000 solution IM or SC epinephrine child 0.01 ml/kg/dose up to 0.4mL/dose 1:10 000 epinephrine if signs and symptoms are SEVERE (laryngeal edema, severe bronchospasm and shock) then give: epinephrine via IV or endotracheal tube starting at 1 ml of 1:10 000 diphenhydramine 50mg IM or IV(Benadryl) methylprednisolone 50-100 mg IV dose depending on severity salbutamol via nebulizer if bronchospasm present t acute intoxication - slurred speech, CNS depression, disinhibited behavior, poor coordination nystagmus, diplopia, dysarthria, ataxia > coma blackouts frank hypotension (peripheral vasodialtion) t obtundation - may be due to alcohol intoxication, but must rule out: associated head trauma cerebral atrophy + repeated falls > increased subdural risk associated depressant/street drugs synergistic with alcohol > respiratory/cardiac depression hypoglycemia: must screen with bedside glucometer
MCCQE 2000 Review Notes and Lecture Series

ALCOHOLIC EMERGENCIES

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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS . . . CONT.

hepatic encephalopathy precipitating factors: GI bleed, infection, sedation, electrolyte abnormalities, protein meal Wernickes encephalopathy horizontal or vertical nystagmus, CN VI paresis, confusion, ataxia ocular findings may be absent at time of presentation give thiamine other neurological problems e.g. post-ictal state following seizures induced by alcohol withdrawal t syndromes of withdrawal (may occur before blood alcohol level reaches zero) 1) Mild withdrawal 6-8 hours after last intake generalized tremor, anxiety, agitation but no delerium autonomic hyperactivity, insomnia, nausea, vomiting 2) Alcoholic hallucinosis visual and auditory hallucinations onset: 24-36 hours after stopping intake vital signs often normal 3) Alcohol withdrawal seizures usually brief, generalized tonic-clonic seizures focal findings or prolonged seizure > do CT scan > LP 4) Delirium Tremens - (5% of untreated withdrawal patients) high rate of mortality 3-5 days after stopping alcohol severe confusional state agitation, insomnia, hallucinations/delusions, tremor, tachycardia hyperpyrexia, diaphoresis t treatment of alcohol withdrawal many protocols 10-20 mg diazepam(Valium) PO/IV q1h prn for agitation no upper limit 100 mg thiamine IM then 100 mg PO x 3 days patient with DTs must be admitted Metabolic Abnormalities t alcoholic ketoacidosis history of chronic alcohol intake, malnourished, abdominal pain lab findings of metabolic acidosis, positive nitroprusside test, glucose low and osmolality normal, ethanol level zero treatment: dextrose, thiamine and normal saline t abnormal alcohols ethylene glycol > CNS,CVS, renal findings methanol early: lethargy, confusion late: headache, visual changes, N&V, abdo pain, tachypnea both produce severe metabolic acidosis with anion gap and osmolal gap ethanol co-ingestion is protective treatment IV 10% ethanol bolus and drip to achieve blood level of 20 mmol/L alcohol loading may be done PO fomepizole (4-mp) if available urgent hemodialysis required t lesser electrolyte abnormalities hypomagnesemia hypophosphatemia hypocalcemia

Notes

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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS . . . CONT.

GI Abnormalities t gastritis common cause of abdominal pain and GI bleed in chronic alcohol users t pancreatitis serum amylase very unreliable in patients with chronic pancreatitis hemorrhagic form (15%) associated with increased mortality t hepatitis AST/ALT ratio > 2 suggests alcohol as the cause t peritonitis occasionally accompanies cirrhosis leukocytosis, fever, generalized abdominal pain paracentesis for diagnosis t GI bleeds most commonly gastritis or ulcers, even if patient known to have varices must consider Mallory-Weiss tear often complicated by underlying hematologic abnormalities Miscellaneous Problems t dysrhythmias (holiday heart) binging precipitates arrhythmias atrial fib, PAT, PVCs treatment: abstinence medications depending on severity t rhabdomyolysis presents as acute weakness associated with muscle tenderness usually occurs after prolonged immobilization increased creatinine kinase, hyperkalemia myoglobinuria - may lead to acute renal failure treatment: IV fluids, forced diuresis (mannitol) t fever look for a source of fever atypical pneumonias (Gram negatives, anaerobes, TB) meningitis peritonitis hepatitis not a benign finding in an alcoholic alcoholics are slightly immunosuppressed

Notes

VIOLENT PATIENTS

t SAFETY FIRST - yourself, patient, staff, other patients t always consider and rule out organic causes (as they can be fatal) t leading organic causes are EtOH, drugs, and head injuries

Differential Diagnosis t organic drugs/toxins/withdrawal metabolic (electrolyte abnormalities, hypoglycemia, hypoxia) infections (sepsis, encephalitis, brain abscess etc...) endocrine (Cushings, thyrotoxicosis) CNS (head injuries, tumour, seizure, delirium and dementia) t functional/psychiatric situational crisis schizophrenia, bipolar disorder (manic), personality disorder Prevention t be aware and look for prodromal signs of violence prior history of violence or criminal behavior anxiety, restless defensiveness, verbal attacks t de-escalate the situation early - may not always work address the patients anger empathize

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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS . . . CONT.

Restraints t physical present option to patient in firm but non-hostile manner demonstrate sufficient people to carry it out restrain supine or on side suction and airway support available in case of vomiting t pharmacologic often necessary - may mask clinical findings and impair exam haloperidol 5-10 mg IM (be prepared for dystonic reactions, especially with multiple does of neuroleptics over a short period) + lorazepam 2 mg IM look for signs of anticholinergic OD first (see Toxicology Section) t once restrained, search person/clothing for drugs and weapons History t antecedent and precipitating events and locale t drugs prescription over-the-counter (antihistamines, anticholinergics, stimulants) recreation/abuse/steroids withdrawal reaction t past medical history (especially diabetes mellitus) t past psychiatric history and past legal history t patients insight t ask family/friends what they think is wrong Physical Exam t vitals temperature often increased in delirium or toxic psychosis hypothermia may have altered mental status t signs of trauma - especially head and neck t neurologic exam, including brief mental status t signs of drug toxicity and needle marks t signs of hypoglycemia Investigations t screening bloodwork: CBC, lytes, glucose, creatinine, BUN, osmolality t selective drug and toxin screen (see Toxicology Section)

Notes

SUICIDAL PATIENT (see Psychiatry Notes) SEXUAL ASSAULT

t involve local/regional Sexual Assault Team

General Management Principles t ABCs first t ensure patient is not left alone and ongoing emotional support provided t set aside adequate time for exam (usually 1 1/2 hours) t obtain consent for: medical exam and treatment collection of evidence disclosure to police > notify police as soon as consent obtained t use Sexual Assault Kit to ensure uniformity and completeness t samples > labelled immediately > passed directly to police t offer community crisis resources (e.g. shelter, hotline) History t who ? how many ? when? t where did penetration occur? t what happened ? any weapons or physical assault? t post-assault activities (urination, defecation, change of clothes, shower, douche, etc ...)

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AN APPROACH TO SELECTED COMMON ER PRESENTATIONS . . . CONT.

t gynecologic history gravity, parity last menstrual period contraception last voluntary intercourse (sperm motile 6-12 hours in vagina, 5 days in cervix) allergies and past medical history Physical Exam t evidence collection is always secondary to treatment of serious injuries t never retraumatize a patient with the examination t general examination mental status sexual maturity patient should remove clothes and place in paper bag document abrasions, bruises, lacerations, torn frenulum/broken teeth (indicates oral penetration) t pelvic exam and specimen collection ideally before urination or defecation examine for seminal stains, hymen, signs of trauma collect moistened swabs of dried seminal stains hair clippings with dried semen pubic hair combings and cuttings posterior fornix secretions if present or aspiration of saline irrigation immediate wet smear for motile sperm air-dried slides for immotile sperm, acid phosphatase, ABO group Pap smear endocervical culture for gonorrhea and chlamydia speculum exam lubricate with water only vaginal lacerations, foreign bodies t other specimens to be obtained fingernail scrapings anus/mouth cultures and smears if appropriate saliva sample from victim VDRL - repeat in 3 months if negative serum -HCG blood for ABO group, Rh type baseline serology (e.g. hepatitis, HIV) Treatment t medical suture lacerations tetanus prophylaxis gynecology consult for foreign body, complex lacerations treat as presumed positive for gonorrhea and chlamydia trichomonas may start prophylaxis for hepatitis B and HIV pre and post counselling for HIV testing t pregnancy prophylaxis offered patient exposed midcycle is at highest risk ethinyl estradiol 100mg and norgestrel 1mg or equivalent (Morning after pills) stat with antiemetic prn repeat in 12 hours t psychological high incidence of psychological sequelae have victim change and shower after exam completed follow-up with MD in rape crisis centre within 24 hours best if patient does not leave ED on own Male Victims t approach is the same t attention to mouth and rectum
Emergency Medicine 32

Notes

MCCQE 2000 Review Notes and Lecture Series

TOXICOLOGY
APPROACH TO THE OVERDOSE PATIENT
Principles of Toxicology t All substances are poisons ... The right dose separates a poison from a remedy t 5 questions to consider with all ingestions is this a toxic ingestion? can the agent be removed? what is alternate treatment? would decontamination be dangerous? what options are available? t suspect overdose when altered level of consciousnes /coma young patient with life-threatening arrhythmia trauma patient bizarre or puzzling clinical presentation

Notes

ABCs OF TOXICOLOGY

t basic axiom of care is symptomatic and supportive treatment t can only address underlying problem once patient is stable A Airway B Breathing C Circulation (consider stabilizing the C-spine) D1 Drugs ACLS as necessary to resuscitate the patient universal antidotes D2 Draw bloods D3 Decontaminate (protect yourself!) E Expose (look for specific toxidromes)/Examine the Patient F Full vitals, ECG monitor, Foley, x-rays, etc... G Give specific antidotes, treatments GO BACK!! Reassess t treatments which will never hurt any patient and which may be essential

D1 - UNIVERSAL ANTIDOTES

Oxygen t do not deprive a hypoxic patient of oxygen no matter what the antecedent medical history (i.e. even COPD and CO2 retention) t if depression of hypoxic drive > intubate and ventilate t only exception: paraquat or diquat exposure (inhalation or ingestion) Thiamine (Vitamin B1) t give 100 mg IV/IM to all patients prior to IV/PO glucose t a necessary cofactor for glucose metabolism, but do not delay glucose if thiamine unavailable t purpose is to prevent Wernicke-Korsakoff syndrome Wernickes encephalopathy - ophthalmoplegia, ataxia, global confusion untreated, may progress to Korsakoffs psychosis (disorder in learning and processing of new information) treatment: high dose thiamine (1000 mg/day x 3 days) most features usually irreversible t populations at risk for thiamine deficiency alcoholics anorexics hyperemesis of pregnancy t in ED, must assume all undifferentiated comatose patients are at risk Glucose t give to any patient presenting with altered LOC t do dextrostix prior to glucose administration (if time permits) t 0.5-1.0 g/kg immediately (D50W in adults, D25W in children)

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TOXICOLOGY . . . CONT.
Naloxone t antidote for opioids t used in the setting of the undifferentiated comatose patient t loading dose adults 2 mg initial bolus IV/IM/SL/SC or via ETT 8-10 mg (0.1 mg/kg) if no response after 5 minutes and narcotic use still suspected known chronic user, suspicious history, or evidence of tracks 0.01 mg/kg (to prevent acute withdrawal) child 0.01 mg/kg initial bolus 0.1 mg/kg if no response and still suspect narcotic t maintenance dose may be required because half-life of naloxone much shorter than many narcotics (half-life of naloxone is 30-80 minutes) continuous infusion at 2/3 of original effective dose per hour, titrate to effect

Notes

D2 - DRAW BLOODS

t essential bloods CBC, electrolytes, urea, creatinine glucose (and dextrostix), PT/PTT ABGs, measured O2 sat osmolality ASA, acetaminophen levels t potentially useful bloods drug levels Ca2+, Mg2+, PO43 protein, albumin, lactate, ketones and liver tests

Serum Drug Levels t treat the patient, not the drug level t where the levels make a difference if in toxic range methanol ethylene glycol carboxyhemoglobin methemoglobin iron lithium acetaminophen ASA theophylline phenobarbital digoxin t available on most general serum screens alcohols except ethylene glycol sedative/hypnotics including barbiturates ASA acetaminophen t specific requests ethylene glycol benzodiazepines (qualitative only) bromide ethchlorvynol (obsolete sleep drug) t urine screens also available (qualitative only) Important Concepts t anion gap (AG) Na+ (Cl + HCO3), normal range ~10 ~14 mmol/L unmeasured cations: Mg2+, Ca2+ unmeasured anions: proteins, organic acids, PO43, sulfate

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TOXICOLOGY . . . CONT.
t metabolic acidosis increased AG (differential of causes, toxic causes circled) Alcoholic ketoacidosis Methanol Uremia Diabetic ketoacidosis Phenformin/paraldehyde INH/iron Lactate (any drug that causes seizures or shock) Ethylene glycol CO, CN ASA Toluene decreased AG error electrolyte imbalance (increased Na+/K+/Mg++) Li, Br elevation increased serum protein (albumin, IgG, multiple myeloma) normal AG increased K+: pyelonephritis, obstructive nephropathy, RTA IV, TPN decreased K+: small bowel losses, acetazolamide, RTA I, II t osmolal gap (measured - calculated) osmoles normally about 10 mOsmol/L or less calculated osmolality = 2 Na+ + BUN + blood glucose (mmol/L) increased osmolal gap alcohols (ethanol, methanol, ethylene glycol) glycerol, mannitol, sorbitol acetone others t oxygen saturation gap (measured - calculated) O2 saturation measured by absorption spectrophotometry calculated from Hb/O2 saturation curve increased O2 saturation gap carboxyhemoglobin methemoglobin sulfhemoglobin

Notes

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TOXICOLOGY . . . CONT.
Table 7. Use of the Clinical Laboratory in the Initial Diagnosis of Poisoning
Test ABGs Finding hypoventilation (elevated Pco2) hyperventilation electrolytes anion-gap metabolic acidosis hyperkalemia hypokalemia hypoglycemia elevated osmolar gap Selected Causes

Notes

CNS depressants (opioids, sedative-hypnotic agents, phenothiazines, and EtOH) Salicylates, CO, other asphyxiants A MUDPILE CAT digitalis glycosides, fluoride, potassium theophylline, caffeine, beta-adrenergic agents, soluble barium salts, diuretics oral hypoglycemic agents, insulin, EtOH EtOH, methanol, ethylene glycol, isopropyl alcohol, acetone TCAs, quinidine, other class Ia and Ic antiarrhythmic agents quinidine and related antiarrhythmics, terfenadine,astemizole calcium antagonists, digitalis glycosides, phenylpropanolamine CHIPES Calcium, Chloral hydrate, CCl4, Heavy metals, Iron, Potassium, Enteric coated, Salicylates, and some foreign bodies Acetaminophen (may be the only clue to a recent ingestion)

glucose osmolality and osmolar gap ECG

wide QRS complex prolongation of QT interval atrioventricular block

abdominal x-ray

radiopaque pills or objects

serum acetaminophen

elevated level (>140 mg/l 4 hours after ingestion)

D3 - DECONTAMINATION
t PROTECT YOURSELF FIRST Ocular Decontamination t saline irrigation to neutral pH t alkali exposure requires opthalmology consult Dermal Decontamination t remove clothing t brush off toxic agents t irrigate all external surfaces Gastrointestinal Decontamination t activated charcoal (AC) absorption of drug/toxin to charcoal prevents availability and promotes fecal elimination single dose will prevent significant absorption of many drugs and toxins exceptions are acids, alkalis, cyanides, alcohols, Fe, Li dose = 1 g/kg body weight or 10 g/g drug injested cathartics probably no longer have any clinical indication multidose activated charcoal (MDAC) can increase drug elimination without charcoal, gut continuously absorbs toxins; MDAC interrupts the enterohepatic circulation of some toxins and binds toxin diffusing back into enteral membrane from the circulation dose various regimes continue until nontoxic or charcoal stool
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TOXICOLOGY . . . CONT.
t whole bowel irrigation 500 cc (child) to 2000 cc (adult) of balanced electrolyte solution/hour by mouth until clear effluent per rectum indications awake, alert patient who can be nursed upright delayed release product drug/toxin not bound to charcoal drug packages - if any evidence of breakage > emergency surgery contraindications evidence of ileus, perforation, or obstruction t endoscopic removal indicated for drugs that are toxic that form concretions that are not removed by conventional means t gastric lavage: historical

Notes

E - EXAMINE THE PATIENT

t important to examine for : vital signs (including temperature), skin (needle tracks, colour), mucous membranes, odours and CNS t head-to-toe survey, including C-spine signs of trauma signs of seizures (incontinence, tongue biting, etc...) signs of infection (meningismus) signs of chronic alcohol abuse signs of drug abuse (track marks, nasal septum erosion) mental status

SPECIFIC TOXIDROMES
Narcotics, Sedatives/Hypnotics, Alcohol Overdose t signs and symptoms hypothermia bradycardia hypotension respiratory depression dilated/constricted pupils CNS depression Sympathomimetics t signs and symptoms increased temperature CNS excitation (including seizures) tachycardia nausea and vomiting hypertension diaphoresis dilated pupils t drugs amphetamines caffeine cocaine ephedrine (and other decongestants) LSD PCP theophylline thyroid hormone ASA toxicity looks like sympathomimetic overdose sedative/hypnotic withdrawl (including alcohol) also similar Drug / Substance Withdrawal t withdrawal state generally opposite to the physiological effect of the drug t signs and symptoms of sedative withdrawal increased temperature agitation tachycardia tremor hypertension hallucinations dilated pupils seizures diaphoresis t drugs sedatives/hypnotics alcohol
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TOXICOLOGY . . . CONT.
Cholinergic t signs and symptoms (DUMBELS) Diaphoresis, diarrhea, decreased blood pressure Urination Miosis Bronchorrhea, bronchospasm, bradycardia Emesis, excitation of skeletal muscle Lacrimation Salivation, seizures t drugs cholinergics (nicotine, mushrooms) anticholinesterases (physostigmine, organophosphates) Anticholinergics t signs and symptoms hyperthermia Hot as a Hare dilated pupils Blind as a Bat decreased sweating Dry as a Bone vasodilatation Red as a Beet agitation Mad as a Hatter tachycardia hypo/hypertension ileus urinary retention t drugs antidepressants Flexeril Tegretol antihistamines (e.g. Gravol, diphenhydramine) antiparkinsonians antipsychotics antispasmotics belladonna alkaloids (e.g. atropine, scopolamine) Extrapyramidal t signs and symptoms dysphonia rigidity and tremor dysphagia torticollis laryngospasm trismus oculogyric crisis t drugs major tranquilizers Hemoglobin Derangements t signs and symptoms increased respiratory rate decreased level of consciousness seizures cyanosis (unresponsive to O2) t causes carbon monoxide poisoning (carboxyhemoglobin) drug ingestion (methemoglobin, sulfhemoglobin) Metal Fume Fever t signs and symptoms abrupt onset of fever, chills, myalgias metallic taste in mouth nausea and vomiting headache fatigue (delayed respiratory distress) t caused by fumes from heavy metals (welding, brazing, etc...)

Notes

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TOXICOLOGY . . . CONT.
G - GIVE SPECIFIC ANTIDOTES AND TREATMENTS
Table 8. Toxins and Antidotes
Toxin Acetaminophen Anticholinergics Benzodiazepines Beta-blockers Calcium Channel blockers Carbon Monoxide Cyanide Digitalis Heparin Iron Methanol/Ethylene glycol Nitrites Opioids Organophosphates Salicylates TCAs Warfarin Antidote/Treatment N-acetylcysteine *Physostigmine Flumazenil Glucagon Calcium chloride or gluconate, glucagon 100% oxygen, hyperbaric O2 Lilly kit (amyl nitrite, then sodium nitrite): Na thiosulfate stop dig, use FAB fragments, restore K+ Protamine Sulfate Deferoxamine Ethanol Methylene Blue Naloxone Atropine, Pralidoxime alkalinize urine, restore K+ Sodium bicarbonate Vitamin K; (FFP if necessary) * No longer available in Canada

Notes

SPECIFIC TREATMENTS
ASA Overdose t acute and chronic (elderly with renal insufficiency) t clinical hyperventilation (central stimulation of respiratory drive) metabolic acidosis tinnitus, confusion, lethargy coma, seizures, hyperthermia, non-cardiogenic pulmonary edema, circulatory collapse t blood gases: 1. respiratory alkalosis 2. metabolic acidosis 3. respiratory acidosis t treatment decontamination 10:1 charcoal:drug ratio close observation - serum level alkalinization of urine as in Table 10 to enhance elimination may require K+ supplements for adequate alkalinization consider hemodialysis when severe metabolic acidosis (intractable) increased levels end organ damage (unable to diurese) Table 9. Urine Alkalinization in ASA Overdose
Plasma pH alkaline alkaline acid Urine pH alkaline acid acid Treatment D5W - 1/4 NS with 20 mEq KCl/L + 2 amp HCO3/L at 2-3 cc/kg/hr D5W - 1/4 NS with 40 mEq KCl/L + 3 amps HCO3/L at 2-3 cc/kg/hr D5W with 80 mEq KCl/L + 4 amps HCO3/L

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TOXICOLOGY . . . CONT.
Benztropine (Cogentin) t useful for acute dystonic reaction/dystonia t has euphoric effect and potential for abuse t for acute dystonic reaction 1-2 mg IM/IV then 2mg PO bid x 3 days Calcium Gluconate t for hypotension with Ca++ antagonists t for hydrogen fluoride burns Ca gluconate gel topical or intradermal or both intravenously for systemic hypocalcemia, hyperkalemia Cholinergic Overdose t atropine anticholinergic / antimuscarinic for anticholinesterase poisonings and cholinergic poisonings with muscarinic symptoms 0.03 mg/kg to max 2 mg/dose (may repeat q 10-15 min until secretions dry) t pralidoxime (Protopam, 2-PAM) cholinesterase reactivation, nicotinic symptoms time limited to 24 hours organophosphate poisonings only 25-50 mg/kg over 5 min IV q6h up to 1-2 g for adults Diphenhydramine t for acute dystonic reactions 1-2 mg/kg IM/IV then 25 mg PO qid x 3 days Ethanol t used to block the metabolism of methanol and ethylene glycol preventing toxicity t dialysis if ethanol treatment unsuccessful FAB (Digibind) t for acute overdose of digoxin t use in combination with activated charcoal t indications life threatening arrhythmias unresponsive to conventional therapy (ventricular fibrillation, ventricular tachycardia, conduction block) 6 hr serum digoxin > 19 nmol/L (therapeutic < 2.6) initial serum K+ > 6 mmol/L history of ingestion > 10 mg adult, 6 mg child t dose 1 vial = 40 mg Digibind neutralizes 0.6 mg digoxin cost of one vial = $200 empirically: 20 vials onset of action 30 minutes renal elimination half life 16-20 hours Flumazenil t specific benzodiazepine (BZ) antagonist t indications iatrogenic BZ oversedation to reverse BZ anesthesia t contraindications known seizure disorder mixed OD (especially if TCA suspected) BZ dependence or chronic use t dose adult: 0.3 mg IV (q5minutes to maximum 1.0 g) child: 10 g/kg (as above, maximum 0.3 mg) t CAUTION most BZ have prolonged half life compared to flumazenil if re-sedation occurs, repeat doses or IV infusion may be indicated
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Notes

MCCQE 2000 Review Notes and Lecture Series

TOXICOLOGY . . . CONT.
Fomepizole (4-mp) t for ethylene glycol overdoses Glucagon t for propranolol, Ca++ antagonist overdoses works as non-beta-adrenergic receptor agonist to increase production of cAMP, thereby increasing contractility 50-100 mg/kg (5-10 mg for adults) slow IV push, then IV at 70 g/kg/hour t for insulin OD (if no access to glucose) 1-2 mg IM Glucose t for oral hypoglycemics, insulin, ethanol, ASA, hepatotoxins t can be given IV, PO or via NG N-acetylcysteine for Acetaminophen Overdose t in metabolizing acetaminophen, cytochrome P450 creates a toxic metabolite that is scavenged by anti-oxidant glutathione, which leads to exhaustion of glutathione stores. N-acetylcysteine substitutes for glutathione to prevent liver damage. minimum toxic dose of acetaminophen: 150-200 mg/kg increased risk of toxicity if: chronic EtOH and/or anti-convulsant drugs t clinical: no symptoms serum acetaminophen level, see nomogram evidence of liver/renal damage - delayed > 24 hours increased AST, PT decreased glucose, metabolic acidosis, encephalopathy indicates a poor prognosis t treatment decontamination serum acetaminophen level 4 hours post ingestion measure liver enzymes and PT/PTT use the Rumack-Matthew Nomogram N-acetylcysteine according to dosing nomogram Oxygen t critical for CO poisoning t hyperbaric O2 (efficacy unclear) suggested for pregnant and unconscious patients with CO poisoning t hyperbaric O2 (efficacy unclear) suggested for cyanide, hydrogen sulfide poisoning, etc... Sodium Bicarbonate (HCO3) t for TCAs t indications with TCAs prolongation of QRS > 0.16 msec ventricular arrhythmias conduction delays seizures at pH ~7.55 t dose: 1 mEq/kg q 10-15 min bolus slowly (no indication for continuous infusion) Vitamin K1 t for coumadin, rat poison overdose t dosage protocol (adjust to INR ratios as needed) PT 25-30 withhold drug PT 30-40 K1 2.5-5.0 mg PO PT 40-50 admit Vit K1 10 mg IV over 10 min require 1 mg/mL to drive coagulation factor synthesis onset ~ 2 hours PT > 50, bleeding give stored plasma (~3000 mL plasma for 70 kg male) need 1000 ml to restore 33% factors increased Vit K dosing (q4h) may require phenobarbital, factor IX concentrate, repeated charcoal, exchange transfusion
MCCQE 2000 Review Notes and Lecture Series

Notes

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TOXICOLOGY . . . CONT.
pH ALTERATION
t see Table 10 t if toxin has potential for ion-trapping at physiologically achievable pH t urine alkalinization urine pH 7.5-8.0 potentially useful for salicylates, phenobarbital evidence of usefulness for phenobarbital is equivocal

Notes

EXTRA-CORPOREAL DRUG REMOVAL (ECDR)

Criteria for Hemodialysis t toxins that have water solubility low protein binding low molecular weight adequate concentration gradient small volume of distribution (VD) or rapid plasma equilibration t removal of toxin will cause clinical improvement t advantage is shown over other modes of therapy t greater morbidity from prolonged supportive care t predicted that drug or metabolite will have toxic effects t impairment of normal routes of elimination (cardiac, renal, or hepatic) t clinical deterioration despite maximal medical support t useful for toxins at the following blood levels: alcohols methanol: > 15.6 mmol/L ethylene glycol: > 8 mmol/L salicylates acute: > 7.28.7 mmol/L (within 6 hours of ingestion) chronic: > 4.34.8 mmol/L lithium acute: > 4.0 mmol/L (within 6 hours of ingestion) chronic: > 2.5-4.0 mmol/L bromine: > 15 mmol/L phenobarbital: 430650 mmol/L chloral hydrate (> trichloroethanol): > 200 mg/kg Criteria for Hemoperfusion t as for hemodialysis t absorbent has greater drug binding capacity than protein or tissue t useful for theophylline: > 330 mmol/L (chronic), > 550 mmol/L (acute) short acting barbiturates (secobarbital) non-barbiturate sedative-hypnotics (phenytoin, carbemazepine, disopyramide, paraquat, methotrexate, Amanita phalloides)

DISPOSITION FROM THE EMERGENCY DEPARTMENT

t discharge home vs. prolonged ED observation vs. admission t methanol, ethylene glycol delayed onset admit and watch clinical and biochemical markers t tricyclics prolonged/delayed cardiotoxicity warrants admission to monitored (ICU) bed if asymptomatic and no clinical signs of intoxication 6 hour Emergency Department observation adequate with proper decontamination sinus tachycardia alone (most common finding) with history of OD warrants observation in ED

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TOXICOLOGY . . . CONT.
t hydrocarbons/smoke inhalation pneumonitis may lag 6-8 hours consider observation for repeated clinical and radiographic examination t ASA, acetaminophen if borderline level, get second level 2-4 hours after first t oral hypoglycemics admit all patients for minimum 24 hours if hypoglycemic Psychiatric Consultation t once patient medically cleared, arrange psychiatric intervention (if required) t beware - suicidal ideation may not be expressed older, solitary male, incarcerated individual

Notes

ACLS ALGORITHMS
ABCs CPR until defibrillator attached VF/VT on defibrillator monitor defibrillate (up to 3 times if VF/VT persists after shock) (200J, 200-300J, 360J) persistent or recurrent VF/VT continue CPR intubate establish IV access Epinephrine 1mg IV push repeat every 3-5 minutes defibrillate (360 J) if VF/VT persists, administer drugs of probable benefit: Lidocaine 1.0-1.5 mg/kg IV push. Repeat in 3-5 minutes to maximum total dose of 3mg/kg Bretylium 5 mg/kg IV push. Repeat in 5 minutes at 10mg/kg, maximum total dose 35 mg/kg Amiodarone 150 mg IV over 10 minutes; can be repeated (not included in current AHA ACLS guidelines) Magnesium sulfate 1-2 g IV in torsades de pointes or suspected hypomagnesemia or severe refractory VF Procainamide 30 mg/minute in refractory VF, maximum total dose 17 mg/kg Defibrillate (360J) after each dose of medication (i.e. drug-shock, drug-shock, etc...)

Figure 3. Algorithm for Ventricular Fibrillation and Pulseless Ventricular Tachycardia

Adapted from American Heart Association Advanced Cardiac Life Support. JAMA 268:2217, 1992. Reproduced with permission.

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ACLS ALGORITHMS . . . CONT.

Pulseless Electrical Activity includes: electromechanical dissociation idioventricular rhythms ventricular escape rhythms bradyasystolic rhythms postdefibrillation idioventricular rhythms continue CPR, intubate, obtain IV access assess blood flow using Doppler ultrasound if blood flow present treat for severe hypotension (IV fluids, norepinephrine, dopamine) if blood flow absent consider possible causes and treat: hypovolemia hypoxia cardiac tamponade tension pneumothorax hypothermia massive pulmonary embolism drug overdose (tricyclics, digitalis, -blockers, Ca++ channel blockers) hyperkalemia acidosis massive acute MI Epinephrine 1 mg IV push, repeat every 3-5 minutes if no response consider one of the following epinephrine protocols: 2-5 mg IV push every 3-5 minutes 1 mg - 3 mg - 5 mg IV push (3 minutes apart) 0.1 mg/kg IV push every 3-5 minutes if bradycardia present, absolute (< 60 beats/minute) or relative, give Atropine 1 mg IV, repeat every 3-5 minutes up to a total of 0.04 mg/kg

Notes

Figure 4. Algorithm for Pulseless Electrical Activity Algorithm

Adapted from American Heart Association Advanced Cardiac Life Support. JAMA 268:2217, 1992. Reproduced with permission.

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ACLS ALGORITHMS . . . CONT.

CPR, intubate, obtain IV access confirm asystole in more than one lead consider possible causes: hypoxia hyperkalemia hypokalemia preexisting acidosis drug overdose hypothermia consider immediate transcutaneous pacing

Notes

Epinephrine 1 mg IV push, repeat every 3-5 minutes Atropine 1 mg IV, repeat every 3-5 minutes up to a total of 0.04 mg/kg if unsuccessful, consider: high dose epinephrine protocol sodium bicarbonate termination of efforts

Figure 5. Algorithm for Asystole

Adapted from American Heart Association Advanced Cardiac Life Support. JAMA 268:2217, 1992. Reproduced with permission.

ABCs, secure airway, oxygen, IV access, attach monitor history, physical exam, 12-lead ECG, portable chest X-ray serious signs or symptoms? chest pain, shortness of breath, decreased level of consciousness low BP, shock, pulmonary congestion, CHF, acute MI No type II 2 AV heart block? 3 AV heart block? No observe Yes pacer insertion TCP in interim Yes Atropine 0.5-1.0 mg transcutaneous pacemaker (TCP) Dopamine 5-20 g/kg/minute Epinephrine 2-10 g/minute Isoproterenol 2-10 g/minute

Figure 6. Algorithm for Bradycardia

Adapted from American Heart Association Advanced Cardiac Life Support. JAMA 268:2217, 1992. Reproduced with permission.

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ACLS ALGORITHMS . . . CONT.

ABCs, secure airway, oxygen, start IV, attach monitor history, physical exam, 12-lead ECG, portable chest X-ray patient unstable? (chest pain, SOB, decreased LOC, low BP, shock, pulmonary edema, CHF, MI) No or borderline Yes if ventricular rate >150 beats/minute prepare for immediate cardioversion

Notes

atrial fibrillation or flutter

paroxsymal supraventricular tachycardia consider vagal manoeuvre Adenosine 6 mg IV push, if no response in 1-2 minutes, use 12 mg IV push (may repeat once) complex width?

wide-complex tachycardia of uncertain type Lidocaine 1-1.5 mg/kg push every 5-10 minutes Lidocaine 0.5-0.75 mg/kg IV push, up to total dose 3 mg/kg Adenosine 6 mg IV push, if no response in 1-2 minutes, use 12 mg push (may repeat once)

ventricular tachycardia

consider: Diltiazem -blocker Verapamil Digoxin Narrow BP normal or high BP low or unstable

Lidocaine 1-1.5 mg/kg push every 5-10 minutes Lidocaine 0.5-0.75 mg/kg IV push, up to total dose 3 mg/kg Procainamide 20-30 mg/minute up to total 17 mg/kg Bretyllium 5-10 mg/kg over 8-10 minutes, up to total 30 mg/kg over 24 hours

Wide Lidocaine 1-1.5 mg/kg IV push Procainamide 20-30 mg/minute up to total 17 mg/kg synchronized cardioversion

Verapamil 2.5-5 mg IV then 5-10 mg IV after 15-30 mins consider Digoxin, -blocker Diltiazem

Figure 7. Algorithm for Tachycardia

Adapted from American Heart Association Advanced Cardiac Life Support. JAMA 268:2217, 1992. Reproduced with permission.

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