Coma- Causes, Diagnosis,
Treatment and Management
2019
Definition
• The patient is not arousable at all to verbal or physical
stimuli, and no attempt is made to avoid painful or
noxious stimuli
• light coma-respond to noxious stimuli
• deep coma-patient do not respond at all
• The level or grade of consciousness to be assessed:
1)GCS
2)The AVPU scale :
A---alert & aware
V---responds to verbal stimuli
P---responds to painful stimuli
U---unresponsive
Terminology
• Delirium :a state of disturbed consciousness with motor
restlessness and disorientation
• Confusion: inability to maintain a coherent sequence of
thoughts, usually by in attention and disorientation
• Obtundation: awake but not alert, psychomotor
retardation is present
• Drowsiness or lethargy/ Stupor:be aroused by noxious
stimuli only ; little motor or verbal acti-vity once aroused
Initial assessment of the comatose
patient
Coma may vary in degree
in its deepest stages no reaction of any kind is obtained;
corneal, pupillary, pharyngeal, tendon and plantar
reflexes are all absent.
Despite the clear descriptions of coma, quantification is
difficult.
So Glasgow coma scale is almost universally used for
this purpose. This measure must be charted from time
to time while the patient is under observation.
Initial assessment of the comatose
patient
• Coma may vary in degree
• in its deepest stages no reaction of any kind is obtained;
• corneal, pupillary, pharyngeal, tendon and plantar
reflexes are all absent.
• Despite the clear descriptions of coma, quantification is
difficult.
So Glasgow coma scale is almost universally used for
this purpose. This measure must be charted from time to
time while the patient is under observation.
GCS
• Eye opening (E)Scale
• Spontaneous4
• To loud sound3
• To pain2
• Nil1
Best motor response (M)
• Obeys 6
• Localizes 5
• Withdraws (flexion) 4
• Abnormal flexion positioning 3
• Extension 2
• Nil1
Verbal response (V)
• Oriented 5
• Confused 4
• Inappropriate words 3
• Incomprehensible sounds 2
• Nil 1
Causes of coma
• Brainstem lesions- infarction, hemorrhage, encephalitis,
abscess, meningitis, bacterial toxemia, tumor, trauma,
neurosurgical intervention.
• Metabolic abnormalities- diabetes mellitus
(hyperglycemia), hypoglycemia, hepatic failure, renal
failure, respiratory failure, cardiac failure, hyponatremia,
hypokalemia, hypoxia, hypothyroidism.
• Drugs and physical agents- anesthetic agents, drug
overdose and alcohol ingestion, hypothermia and
hyperthermia.
History
• seek historical data from friends , family , or others
• The rate of onset of neurologic or behavioral changes abrupt onset
favors the CNS hemorrhage or ischemia , or a cardiogenic cause ;
• gradual onset favors a metabolic problem such as electrolyte
disturbance
• history of trauma or on ongoing medical illness
• Suicidal- past attempts at self-harm , and any history of substance
abuse are critical consideration
Physical Examination
• ABCD – primary Assessment focused on minimizing
the secondary insult
1. Hypoxia
2. Hypercarbia
3. Hypotension
4. Hypertension
5. Hyperthermia
6. Hypoglycemia
Assessment con…
• Secondary assessment – focused physical
examination, investigation, treatment -
• Tertiary assessment – detail physical
examination and identification of the
possible, reversible causes
Physical Examination
• Hypothermia : sepsis , hypothyroidism , or enviromental
exposure
• Hyperthermia : CNS infection , sepsis , heat stroke ,
thyrotoxicosis , stroke , exposure to certain
toxins(salicylates,anticholinergics,or
sympathomimmetics)
• systolic BP of over 200 mmHg , with a diastolic BP over
130 mmHg suggested ICH , thyrotoxicosis , or exposure
to sympathomimmetic agents
Physical Examination
• Bradycardia : ↑ICP , hypothyroidism , toxins OD or of
calcium channel blockers or ß-blockers
• Breathing smell : may suggest fetor hepaticus ,
uremia , acetone ,or alcohol
• Respiratory patterns:
a) apneustic: upper pons
b) Bradypnea
c) Cheyne-Stokes respiration : bilateral dysfunction of the
hemispheres or diencephalon;
Physical Examination
Posture :
• Decorticate: diencephalon disorder
• Decerebrate: vestibular nuclei in the medulla
and the vestibulospinal tracts are intact
• In general , patient with decorticate posture has
the better prognosis than the decerebrate
posture in the response to pain
Investigations and Diagnosis of Coma
• Urine- for sugar, albumin and acetone.
• Blood- blood count, estimation of blood glucose, electrolyte
level, blood urea level, blood nitrogen level, blood levels of
common intoxicants, blood smear for malaria parasite and
blood culture.
• Cerebrospinal fluid- for evidence of hemorrhage, meningitis
or encephalitis.
• Analysis of vomit or gastric lavage.
• X-ray skull for evidence of any fracture to show erosion of
sells which would suggest increased intra-cranial pressure,
infection of sinuses…
Investigations and Diagnosis of Coma
• Chest X-ray may reveal carcinoma (metastasis),
bronchiectasis, abscess, cerebral embolism.
• CT-scan or MRI-
• Coma with focal signs or evidence of head injury-whether focal
signs indicate a brainstem or supratentorial lesion. A normal
scan may be seen in patients with hypoglycemia or hepatic
coma.
• Coma without focal signs but with meningeal irritation- brain
imaging for subarachoid hemorrhage.
• Cerebral angiography- useful aid in brain tumor and sub-dural
hematoma.
• EEG- may provide evidence of sub-clinical epilepsy.
Management of Coma
• Removal or control of cause- e.g. gastric lavage and
diuretics in narcotic poisoning.
• Ensure proper respiration- oxygen, ventilation
• When there is deep coma; secretions and vomiting
inhaled into lungs, will soon result in death. The patient
must be nursed in the semi-prone or lateral position with
frequent changes from one side to the other.
• Ensure proper circulation- parentral fluids intravenous
glucose or blood transfusion, vasopressor drug like
dopamine if low blood pressure or shock.
Management of Coma
• Care of bowels and bladder- indwelling catheter,
saline or soap water enema.
• Care of skin- frequent change of position in bed,
alcohol or spirit rub and powdering of skin and
care of mouth.
• Control of secondary infection with antibiotics
especially in presence of fever.
• Early NGT feeding when ever possible
• Neurosurgical intervention- if coma progression
raises the possibility of herniation.
Reading
• Physiology of consciousness
• Path physiology of coma
