PERIOPERATIVE

MONITORING

PROF. Dr. dr. Made Wiryana, SpAn. KIC. KAO

Konsep Dasar Anestesia

• Anestesia: hilangnya kesadaran

• Analgesia: hilangnya rasa nyeri
• “Triad of General Anesthesia”
• Tidak sadar ( sedasi/hipnosis)
• Tidak nyeri ( analgesia )
• Tidak bergerak ( relaksasi /supresi refleks)
Konsep Dasar Managemen Anestesia

• Resusitasi
• Terapi suportif
• Monitoring ketat
 Preoperative management
• Previous adverse responses related • Central Nervous System
to anesthesia • Cerebrovascular insufficiency
• Seizures
• Allergic Reactions
• Sleep apnea
Prolonged skeletal muscle paralysis
•
• Delayed awakening
• Cardiovascular System
• Nausea and vomiting • Exercise Tolerance
• Adverse responses in relatives • Angina
• Prior MI
• HTN
• Claudication
• Lungs • Kidneys
• Exercise Tolerance • Nocturia
• Dyspnea and Orthopnea • Pyuria
• Cough and Sputum Production
• Cigarette consumption
• Pneumonia • Skeletal and Muscular Systems
• Recent upper resp. tract infection • Arthritis
• Osteoporosis
• Liver • Weakness
• Alcohol Consumption
• Hepatitis
• Endocrine System • Reproductive System
• Diabetes mellitus • Menstrual History
• Thyroid gland dysfunction • STD’s
• Adrenal gland dysfunction
• Dentition
• Coagulation • Dentures
• Bleeding tendency • Caps
• Easy bruising
• Hereditary coagulopathies
 Intraoperative monitoring:
Introduction
The most primitive method of monitoring the patient 25
years ago was continuous palpation of the radial
pulsations throughout the operation!!
What is the value of knowing this?
To understand & appreciate the value of clinical
monitoring.
RULE: your clinical judgement/assessment is much
BETTER & much more VALUABLE than the digital
monitor.
To appreciate that modern monitors have made life
much easier for us. They are present to make
monitoring easier for us NOT to be omitted or
ignored.
Intraoperative monitoring:
Introduction
Why do we need intraoperative monitoring???
• To maintain the normal physiology & homeostasis throughout
anesthesia and surgery: induction, maintenance & recovery as
much as possible. To ensure the well being of the pt.
• Surgery is a very stressful condition → severe sympathetic
stimulation, HTN, tachycardia, arrhythmias.
• Most drugs used for general & regional anesthesia cause
hemodynamic instability, myocardial depression, hypotension
& arrhythmias.
• Under GA the pt may be hypo or hyperventilated and may
develop hypothermia.
• Blood loss → anemia, hypotension. So it is necessary to
recognise when need of blood transfusion (transfusion point).
Intraoperative monitoring:
Introduction
The FOUR BASIC Monitors:
• We are NOT authorised to start a surgery in the
absence of any of these monitors:
• ECG.
• SpO2: arterial O2 saturation.
• Blood Pressure: NIBP (non-invasive), IBP (invasive).
• ± [Capnography].
• The most critical 2 times during anesthesia are:
INDUCTION - RECOVERY.
• Exactly like “flying a plane” induction (= take off) &
recovery (= landing). The aim is to achieve a smooth
induction & a smooth recovery & a smooth
intraoperative course.
(1) ECG
Intraoperative monitoring: (1) ECG
Value:
Heart rate.
Rhythm (arrhythmias) usually best identified from lead II.
Ischemic changes & ST segment analysis.
Timing of ECG monitoring: Throughout the surgery: before
induction until after extubation & recovery.
Types & connections of ECG cables:
3-leads: Red=Right YeLLow=Left Black=Apex (can
read leads: I, II, III)
5-leads: Red=Right YeLLow=Left Black=under red
Green=under yellow White=central (can read any of
the 12 leads: I, II, III, avR, avL, avF, V1-V6).
Intraoperative monitoring: (1) ECG
• RULES:
• QRS beep ON must be heard at all times. NO
silent monitors.
• Remember that your clinical judgement is
much more superior to the monitor. Check
peripheral pulsations.
• Cautery → artefacts & fallacies in ECG (noise/
electrical interference) → check radial
(peripheral) pulsations.
• Arrythmias → check radial (peripheral)
pulsations.
(2) SpO2
Intraoperative monitoring: (2) SpO2
It is the most important monitor. It gives a LOT of
information about the pt.
Definition: % of oxy-Hb / oxy + deoxy-Hb.
Timing of SpO2 monitoring: throughout the surgery:
before induction till after extubation & recovery. It is
the LAST monitor to be removed off the pt before the pt
is transferred outside the operating room to recovery
room. SpO2 monitoring should be continued in recovery
room.
Waveform of pulse oximeter = plethysmography
(arterial waveform). It indicates that the pulse oximeter
is reading the arterial O2 saturation. Without the
waveform pulse oximeter readings are unreliable &
incorrect.
Intraoperative monitoring: (2) SpO2
Value:
SpO2: arterial O2 saturation (oxygenation of the pt).
HR.
Peripheral perfusion status (loss of waveform in
hypoperfusion states: hypotension & cold extremeties).
Gives an idea about the rhythm from the plethysmography
wave (arterial waveform). (Cannot identify the type of
arrhythmia but can recognize if irregularity is present).
Cardiac arrest.

N.B. Pulse oximeter tone changes with desaturation

from high pitched to low pitched (deep sound). So
just by listening to the monitor you can recognize: (1)
HR (2) O2 saturation.
Intraoperative monitoring: (2) SpO2
Readings:
• Normal person on room air (O2 = 21%) ˃ 96%.
• Patient under GA (100% O2) = 98-100%.
• It is not accepted for O2 saturation to ↓ below 96%
with 100% O2 under GA. Must search for a cause.
• < 90% = hypoxemia.
• < 85% = severe hypoxemia.
Intraoperative monitoring: (2) SpO2
RULES:
 Keep the sound of the pulse oximeter ON at ALL
times.
 Pay attention to the sound of the pulse oximeter.
NO silent monitors.
 ALWAYS Remember that your clinical judgement is
much more superior to the monitor. Check pt
colour for cyanosis: lips, nails.
 If hypoxemia occurs immediately check the correct
position of the probe on the pt and check the pts
colour: nails & lips, then manage accordingly &
CALL 4 HELP.
(3) Blood Pressure
Artery line
Intraoperative monitoring: (3) BP
• NIBP: (non-invasive ABP monitoring = automated). Gives
readings for: systolic BP, diastolic BP & MAP: Systolic/ diastolic
(mean).
• Value: to avoid and manage extremes of hypotension & HTN.
Systolic BP-Diastolic BP- MAP.
• Avoid ↓ MAP < 60 mmHg (for cerebral & renal perfusion) &
avoid ↓ diastolic pressure < 50 mmHg (for coronary
perfusion).
• Risks of HTN episodes: → (CVS): myocardial ischemia,
pulmonary edema, (CNS): hemorrhagic stoke, hypertensive
encephalopathy. While hypotensive episodes: (CVS):
myocardial ischemia, (CNS): ischemic stroke, hypoperfusion
state metabolic acidosis, delayed recovery, renal shutdown.
Intraoperative monitoring: (3) BP
RULE:
• YOUR clinical judgement is always superior to the monitor.
Must check peripheral pulse volume from time to time (Radial
A, or Dorsalis Pedis A, or Superficial Temporal A) regularly
every 10 minutes.
• Palpation of Radial A → systolic BP ˃ 90 mmHg.
• Palpation of Dorsalis Pedis A → systolic BP ˃ 80 mmHg.
• Palpation of Superficial Temporal A → systolic BP ˃ 80
mmHg.
• i.e If Radial A pulsations are lost = systolic BP is < 90 mmHg.
• If dorsalis pedis & superficial temporal pulsations are lost =
systolic BP is < 80 mmHg.
• Check pt colour for pallor: lips, tongue, nails, conjunctiva.
Intraoperative monitoring: (3) BP
IBP: (invasive arterial blood pressure monitoring)
It is beat to beat monitoring of ABP via an arterial cannula.
Indicated in: major surgeries, during deliberate hypotensive
anesthesia, during the use of inotropes, cardiac surgery, in
surgeries involving extreme hemodynamic changes/instability eg.
pheochromocytoma, repeated ABG sampling.
(4) Capnography (CO2)
Intraoperative monitoring: (4) CO2
Phases of the capnogram:
Balseline: A-B
Upstroke: B-C
Plateau: C-D
End-tidal: point D
Downstroke
Intraoperative monitoring: (4) CO2
Normal range: 30-35 mmHg. (Usually lower than
arterial PaCO2 by 5-6 mmHg due to dilution by dead
space ventilation).
Value (data gained from capnography & ETCO2):
 ETT: esophageal intubation.
 Ventilation: hypo & hyperventilation, curare cleft (spontaneous
breathing trials).
 Pulmonary perfusion: pulmonary embolism.
 Breathing circuit: disconnection, kink, leakage, obstruction,
unidirectional valve dysfunction, rebreathing, exhausted soda
lime.
 Cardiac arrest: adequacy of resuscitation during cardiac arrest,
and prognostic value (outcome after cardiac arrest).
Intraoperative monitoring: (4) CO2
Factors affec ng EtCO2: what ↑ what ↓ EtCO2?
Individual System Monitoring

Position of ETT.
Respiratory System.
CVS & Hemodynamic Monitoring.
CNS: Awareness.
Temperature.
Monitoring after Extubation & Recovery.
(A) Correct Position of ETT
(B) Respiratory Monitoring
 Clinical monitoring:
 Colour: cyanosis: nails, lips, palms, conjunctiva.
 Chest rise & fall (inflation).
 Vapour in ETT (absent in ventilators with humdifiers/if
filter is used).
 Airway pressure.
 Ventilator bellows (return to full inflation during
expiratory phase).
 Ventilator sound: during resp cycle. Abnormal sounds eg.
leakage, disconnection, high airway pressure, alarms.
Pin Safety System Index dan kode
warna
Pneumatic ventilator
Vaporizer
(B) Respiratory Monitoring
• N.B. Various alarms by the ventilator:
NEVER ignore an alarm by the ventilator!
• Low airway pressure: leakage, disconnection.
• High airway pressure: kink, biting of the tube,
bronchospasm, slipped → esophagus.
• Low expired tidal volume: leakage.
• Apnea alarm: disconnection.
• O2 sensor failure: (unfortunately common in many of
our ventilators).
• Flow sensor failure: (unfortunately common in many of
our ventilators).
(B) Respiratory Monitoring
Respiratory Monitors:
 O2 Saturation.
 Capnography EtCO2.
 Airway pressure.
 ABG samples.
(C) CVS Hemodynamic Monitoring
Clinical monitoring:
• Colour: pallor (lips, tongue, nails) = anemia, shock.
• Palpate peripheral pulsations every 10 minutes (Radial A,
Dorsalis pedis A, Superficial temporal A).
• Capillary refilling time: compress nail bed until it is
blanched. After release of pressure refilling should occur
within 2 seconds. If ˃ 5 seconds = poor peripheral
perfusion/circulation.
• UOP:
• Values: it is an indicator of: 1) good hydration 2) good tissue (renal)
perfusion 3) good renal function. [Urine is the champagne of
anesthetists and urologists!!].
• Indications: 1) lengthy surgery ˃ 4 hrs 2) major surgery with major
blood loss 3) C-section: to monitor injury to the bladder or ureter.
• Normal: 0.5-1 ml/kg/hr.
• When the catheter is inserted u must always note the baseline urine
volume at the start of operation.
(C) CVS Hemodynamic Monitoring
Management of oliguria or anuria:
• Check that the line is not kinked or disconnected.
• Palpate the urinary bladder (suprapubic fullness), or
ask the surgeon to palpate it.
• Raise BP (MAP ˃ 80 mmHg): renal perfusion.
• IV fluid challenge.
• Diuretics.
• N.B. Sometimes trendlenberg position (head down)
causes ↓ UOP. Reversal of this posi on results in
immediate flow of urine.
(D) CNS: Awareness
Clinical monitoring:
Signs of pt awareness:
Movement, grimacing (facial expression).
Pupils dilated.
Lacrimation.
Tachycardia.
HTN.
Sweating: is always an alarming/warning sign. Causes:
 Awareness.
 Hypoglycemia.
 Hypercapnia.
 Thyroid storm (thyrotoxic crisis).
 Fever.
Always check the concentration of ur vaporizer & make sure
that ur vaporizer is not empty
Bispectral Index (BIS)
IOC
(E) Temperature Monitoring
• Clinical monitoring: ur hands.
• Monitors: temperature probe: nasopharyngeal,
esophageal.
• AVOID hypothermia < 36oC. Why? & How?
• Especially in pediatrics & geriatrics (extremes of
age).
• Why is it necessary to avoid hypothermia?
(complications of hypothermia):
• Cardiac arrhythmias: VT & cardiac arrest.
• Myocardial depression.
• Delayed recovery (delays drug metabolism).
• Delayed enzymatic drug metabolism.
• Metabolic acidosis ( ssue hypoperfusion → anerobic glycolysis
→ lac c acidosis) & hyperkalemia.
• Coagulopathy.
(F) Monitoring After Extubation &
Recovery
• After extubation: immediately fit the face mask on the pt
(with a slight chin lift) and observe the breathing bag:
• Good regular breathing with adequate tidal volume
• No transmission to the bag → ( respiratory obstruction or apnea )
• BP: within 20% of baseline.
• SpO2: ˃ 92%
• Breathing: regular, adequate tidal volume.
• Muscle power: sustained head elevation for 5 seconds, good
hand grip, tongue protrusion.
• Level of consciousness: fully conscious = 1) obeying orders, 2)
eye opening, 3) purposeful movement.
• MOST IMP: Pt MUST be able to protect his own airway.
To Summarize:
“How do I monitor the patient in OR?”
The 4 basic monitors displayed on the screen:
1) ECG.
2) BP.
3) SpO2.
4) ± Capnogram (EtCO2).
Normal target values for an adult under GA:

• HR: 60-90 (˃ 90 = tachycardia. < 60 = bradycardia).

• BP: 90/60 – 140/90. MAP ˃ 60 mmHg (cerebral & renal
autoregulation). Diastolic BP ˃ 50 mmHg (coronary
perfusion pressure).
• SpO2 ˃ 96% on 100% O2.
• EtCO2 = 30-35 mmHg.
LISTEN
 Listen to the monitor the whole time:
 To the pulse oximeter tone to identify: 1-Heart rate 2-
O2 saturation from the tone (pitch) of pulse oximeter.
 To the sound of the ventilator, to any abnormal sounds,
any alarms.
 RULE: NO silent monitors. ALWAYS keep the HR
sound on. If ur monitor is silent (sound is not
working) u have to look at your monitor the
WHOLE time.
LööK
• Every 5 minutes to note the new BP reading.
• If there is any change in the tone of the pulse
oximeter.
• If there is any irregularity in heart rate & during
the use of diathermy.
Clinical Check / 10 minutes
1) Chest inflation.
2) Ventilator bellows: descend and return to become fully
inflated.
3) Airway pressure.
4) Palpate peripheral pulsations (radial A, or dorsalis pedis A, or
superficial temporal A):
 For pulse volume.
 During the use of cautery.
 In doubt of ECG rhythm (arrythmias).
 In case monitor or ECG disconnected.
5) Pt colour (nails): cyanosis, pallor.
6) Vaporizer:
a) Check concentration opened.
b) Level of the volatile agent (if needs to be filled).
RULES NEVER to FORGET:
• Never start induction with a missing monitor: ECG, BP,
SpO2.
• Never remove any monitors before extubation & recovery.
• NEVER ignore an alarm by the ventilator.
• ALWAYS remember clinical sense & judgement is better &
superior to any monitor. The monitor is present to help u
not to be ignored and not to cancel ur brain.
• Last but by no means least:
• ALWAYS remember that there is NO such thing as “all
monitors disconnected” → check that ur pt is ALIVE!!
Immediately check peripheral & carotid pulsations to make
sure that ur pt is not ARRESTED!! Once u have ensured pt
safety reattach ur monitors once again.