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Critical Incidents duringperioperative period
Dhawala PereraConsultant Anaesthetist
Military HospitalColombo
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Definition
An event which
had the potential
to leadto an undesirable outcome
if left to progress
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Crisis Management Algorithm
COVER ABCDA SWIFT CHECK
A Airway
B Breathing
C Circulation
D Drugs
C CirculationCapnographColour (Saturation)
O Oxygen Supply
Oxygen Analyser
V Ventilation (Ventilated Pts)Vaporisers
E Endotracheal TubeEliminate Machine
R Review Monitors
Review Equipment
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A Awareness, Air embolism, Air in pleura, Anaphylaxis
S Surgical complications, Stimulation and Sepsis
W Wound and Water Intoxication
I Infarct, Insufflation
F Fat syndrome and Full bladder
T Trauma, Tourniquet
C Catheter, Chest drain
H Hyper / Hypoglycaemia, Hyperthermia
E Embolism
C Cement
K K+
A
S
W
I
F
T
C
H
E
C
K
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Laryngeal spasm
Bronchospasm
Inadequate ventilation
Pulmonary Aspiration
Pulmonary oedema
Pneumothorax
Hypotension
Hypertension
Cardiac dysrrhythmias
Venous air embolism
Airway Problems
Respiratory Problems
Cardiovascular Problems
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Anaphylaxis
Intra-arterial injection of TPS
Malignant hyperpyrexia
Suxamethonium apnoea
local anaesthetic toxicity
Drug related complications
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ANAPHYLAXIS
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Anaphylaxis
Due to explosive release histamine & other mediatorsfrom mast cells
Causing : bronchoconstriction
Vasodilatation
Increased capillary permeability
Common with : i.v. induction agents
muscle relaxants
antibiotics
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Signs
Unexplained severe hypotension Tachycardia and cyanosis
Rashes, flushing or pallor, facial oedema
Bronchospasm and increased AWP
Pharyngeal, Laryngeal, Pulmonary or generalized oedema Oozing in the operating site
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Management
Stop of the drug immediately & change the infusion set
Call for help
Ventilate with 100 % O2 Intubate if unintubatedas laryngeal oedema may occur
Position the patient flat and elevate the lower limbs
Give Adrenaline 10 g/kg ( 1000 g = 1mg = 1ml of 1:1000)
if circulation is adequate
0.5-1.0 mg i.m. or in the tongue every 10 min.
if circulation is not adequate
0.5-1.0 mg i.v. (1mg in 10ml) over 1min. titrated
Intravenous volume expansion with crystalloids or colloids
Hydrocortisone 100-500mg i.v.
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Management contd.
H1 antagonists Promethezine 50mg
Chlopheniramine 10mg
H2 antagonists Ranitidine 50mg slow i.v.
Management of bronchospasm
Admit to HDU / ICU
Identify the causative agent and inform the patient
After 1 hr take 10ml of blood for serum tryptase
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LARYNGOSPASM
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LARYNGOSPASM
Inspiratory stridor
High pitched sound during inspiration
higher the pitch greater the obstructionsilent with complete obstruction
Paradoxical chest/abdominal movements (rocking boat effect)
with supra-sternal and sub-costal recession during inspiration
Increased inspiratory efforts/tracheal tug
Desaturation, bradycardia, central cyanosis
LOOK FOR
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LARYNGOSPASM
PRECIPITATING FACTORS
Airway irritation and / or obstruction
Blood/secretions in the airway
Intolerance of oro-pharyngeal airway
Regurgitation and aspiration
Excessive stimulation / "light" anaesthesia
surgical stimulation under light anaesthesia
removal of ETT under light anaesthesia
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Management
1. Cease stimulation / surgery
2. Optimize air entry
Try gentle chin lift/jaw thrust with 100% Oxygen
via pressurised system by closing expiratory valve
3. Request immediate assistance
4. If Partial SV If complete IPPV
5. Deepen anaesthesia with an IV agent if necessary6. Find & Treat the cause
Visualise and clear the pharynx/airway
? aspiration ? airway obstruction ? Light GA
7. Try mask CPAP/IPPV, if this is unsuccessful & DesaturatePropofol & Sux (0.25-0.3mg/kg)
mask CPAP/IPPV with 100% O28. ? Intubate & Ventilate
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FURTHER CARE
Careful postoperative review of the patient to:
confirm a clear airway
exclude pulmonary aspiration
exclude post obstructive pulmonary oedema
exclude distension of stomach
explain what happened to the patient.
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BRONCHOSPASM
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BRONCHOSPASM
Signs
Difficulty in ventilation
SV : wheezing with inadequate, laboured breathing
little thoracic movement
IPPV : high AWP with poor chest expansion
Rhonchi ( absent breath sounds if very severe)
Desaturation & Cyanosis
ETCO2 - rising
sloping expiratory phase
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BRONCHOSPASM
Use COVER ABC to exclude other causesendobronchial and oesophageal intubation
upper airway or tracheal obstruction
bilateral pneumothorax
IfBronchospasm + Hypotension
? Pulmonary oedema? Aspiration
? Anaphylaxis
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Causes
Bronchial asthma or preoperative wheezing Release of Histamine triggered by drugs
Morphine , Atracurium
Intubation or surgical stimulation under inadequate anaesthesia
Aspiration
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Management
Cease stimulation / surgery
Request immediate assistance
Manual ventilation using
slow gentle compressions with
a long expiratory periodto force 100% O2 into chest
Remove triggering factors : Light anaesthesia
Treat other causes : Anaphylaxis , Aspiration
Deepen anaesthesia with Ketamine and Halothane or Isoflurane
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Management contd.
Salbutamol 0.2mg slow i.v. or 3-20 g/min infusion or
5mg in 5ml nebulisation
aminophylline 250mg (5mg/kg) in 20ml slow i.v.
followed by an infusion of 0.6mg/kg/min
Hydrocortisone 200mg i.v.
Other drugs
Ipratropium 0.25mg nebulization
Ketamine 2mg/kg
MgSO4 2g slow i.v.
Adrenaline 1:10000
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Monitor
ECG
for arrhythmias due to
hypercarbia, hypokalaemia, aminophylline
Pulse
BP
SpO2
Clinical Auscultation
ABG
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High airway pressures
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Common problem
Potentially life threatening
Requires systematic approach after exclusion of obvious
and common causes
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Difficult to ventilate Decreased compliance in reservoir bag,
poor chest expansion,
low minute volume
High airway pressure/ alarm Abnormal CO2 trace
Hypoxia
Circulatory collapse
Presentation
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Check patient + review environment
ABC Oximeter, capnograph
Machine + circuit
Surgical activity
Hand ventilate 100% oxygen
Exclude obvious causes
Fighting ventilator - not paralysed Closed expiratory limb - ballooning of reservoir bag
Excessive tidal volumes / ventilator settings
Kinked tubing
Initial response
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Patient
Decreased chest wall compliance Decreased lung compliance
Increased airway resistance
Find the Cause & Treat
CausesNon patient
Circuit/ gas supply
Endotracheal Tube
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Gas supply
O2 flush stuck on
High pressure gas source
Excessive tidal volumes
Non Patient Problems
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Circuit
Blockage, compression, kinking or incorrect connection of: Scavenging,
reservoir bag,
filter,
Humidifier
APL valve,
PEEP valve
Ventilator, angle piece,
tube connector
Breathing hoses + valves etc
Non Patient Problems
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Kinked
Misplaced
OesophagealEndobronchial
Obstructed
Sputum, blood
Cuff herniation
Too small
Non Patient Problems
Endotracheal Tube
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Chest wall rigidity
MH or opioids
Prone / position
Obesity Kyphoscoliosis
Abdominal pressure
Distension
Laparoscopy
Gastroschisis repair
Inadequate paralysis/ fighting ventilator
Patient Problems
Decreased chest wall compliance
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Pneumothorax/ haemothorax
Atelectasis
Pulmonary oedema
Fibrosis
ARDS
Patient Problems
Decreased lung compliance
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Bronchospasm
Foreign body
Anaphylaxis/ anaphylactoid
Aspiration
Amniotic fluid embolism
Patient Problems
Increased airway resistance
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PNEUMOTHORAX
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Pneumothorax
Classification
Simple : the gas is not under tension
Open : continuing communication between source
of the gas and pleural cavity
closed : no communication
Tension Pneumothorax
the gas is under tension as gas flow in to the pleural cavity
is unidirectional. Valve mechanism
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High risk patients
Patient :
After chest trauma or
with lung disease. eg:emphysematous bullae
Surgery :
Kidney, thorax, diaphragm, neck or laparoscopic cholecystectomy
Anaes : Brachial plexus block,
CVP,
Barotrauma due to high pressure
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Signs
Difficulty in ventilation with high airway pressures
Desaturation
Unilateral breath sounds despite withdrawing ETT
Deviation of trachea to opposite side (tension pneumothorax) Hypotension, Tachycardia, arrhythmias
Distended neck veins, raised CVP
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Management
Omit N2O
100% O2
Simple Pneumothorax due to damage to pleura
Ventilate with large Vt and expand the lung during the last sutures IC tube may be necessary
Simple Pneumothorax due to damage to lung
Insert IC tube
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Mgt. : Tension Pneumothorax
If BP falls acutely Em. treatment is life saving
Insert 14G cannula in 2nd IC Space in mid clavicular line
to release the air
to improve ventilation and BP
until chest drain is inserted
Confirm and position of ICT with CXR
Observe the bottle for bubbling and / or swinging
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?? further deterioration
It may be due to:
Increased or continuing air leak
Kinked/blocked/capped/clamped underwater seal drain
Contra-lateral pneumothorax
Misplaced pleural drain tip
Trauma caused by drain insertion Misconnection of drain apparatus
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Further Care
If the problem persists,
Considercardiac tamponade
Consider peri-cardiocentesis and/or opening the chest.
Arrange a chest X-ray and look for:
-state of re-expansion of the lung
-mediastinal shift
-position of the tip of the drain
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HYPERTENSION
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Hypertension
DiagnosisIncrease of BP by >20% of the base line
Aetiology of Perioperative Hypertension
Sympathetic response Pre-existing hypertension
Hypercarbia
Drug effects
Cerebral ischaemia
Preload (Volume overload)
Afterload
h i
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Sympathetic response
Light anaesthesia
Painful stimulus
Emergence
Bladder distention Tourniquet
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Pre-existing hypertension
Essential hypertension
Renovascular
Pre-eclampsia
Autonomic dysreflexia
Other endocrine-e.g. phaeo, hyperthyroid
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Drug Effects
Vasopressors
Withdrawal
E.g. Clonidine
Beta blockers.
Methyldopa.
Interactions-e.g.MAOIs with
PethidineMetaraminol
Ephedrine
Cocaine
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Cerebral Ischaemia
Raised ICP
Carotid/Vertebral occlusion, e.g. from neck positioning
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High Afterload
Aortic cross clamp
Pneumoperitoneum
Hypothermia
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Management
Deepen anaesthesia
volatile agent, anxiolytics and analgesics
Identify the cause & treat
Identify and treat complications
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Treatment for Hypertension
Vasodilators
Alpha-blockers
Beta blockers
Especially if associated with tachycardia
Beware contraindications
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Dilators
Hydralazine:5-10 mg I.V. repeat every 20 min
GTN:
50mg in 50 mls Start @ 3ml/hr & titrate
Na Nitroprusside
Start @ 20 g/min & titrate
Or 0.5-8.0 g/kg/min
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Alpha-blockers
Clonidine:
150 g I.V. in divided doses
Phentolamine:
0.5-1mg increments
B Bl k
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Beta Blockers
Atenolol
1-2mg i.v. up to 10 mg
Esmolol
5g in 500ml 5% dextrose & titrated to heart rate
Indicated with associated
tachycardia,
evidence of cardiac ischaemia, or
known C.A.D
Consider contraindications:
Significant broncospasm
Suspected phaeochromocytoma
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Raised I.C.P.
Mannitol
0.5-2 g/kg I.V.
Moderate hyperventilation
Down to arterial pCO2 30mmHg Frusemide
5-10 mg I.V.
The aim is to preserve cerebral perfusion pressure
Followed by urgent neurosurgical intervention
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HYPOTENSION
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Hypotension
1. Capacity for Compensation
Old Age, Diabetes, Arteriosclerosis2. Oxygen Availability
Hb % , SpO2
3. Organ Dysfunction
Heart, Kidney
Critical BP requiring intervention depends on many factors
Hypotensionassociated with Desaturation is an EMERGENCY
High Risk Patients
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High Risk Patients
Patient :
Inefficient compensatory mechanisms
Hypertensive, Elderly, Cardiac compromised,Autonomic neuropathy, on antihypertensive therapy
Surgical :
Haemorrhage
Fluid loss from GIT
Anaesthesia :Drugs and interactions
Techniques
Positioning
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Diagnosis
30% decrease of BP from baseline BP
< 80mmHg
Causes
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Causes
Preload reduced
HaemorrhageconcealedReduced VR
compression of IVCUterus / Retractors
Head high position
Afterload reduced
Vasodilatation by drugs
SAB / EDB
Anaphylaxis
Sepsis
Contractility reduced
Myocardial ischaemia
Myocardial depression
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Management
Identify & treat The cause
Minimize effect of anaesthesiaReduce or omit Volatile agent
Increase FIO2 50%
If on IPPV reduce Vt & convert I:E ratio to 1:4
Correct hypovolaemiagive rapid fluid challenges and elevate legs
Vasopressors
Ephedrine
Metaraminol (0.005- 0.01 mg/kg i.v. )Phenylephrine (10mg/500ml)
titrated to effect
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HYPOXEMIA
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SaO2 < 90 %,
PaO2 < 60mmHg
HYPOXEMIA
Definition
Mechanisms
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Low FiO2
Inadequate VA
V/Q mismatch
Anatomic shunt
Excess metabolic O2 demand
Low cardiac output
Mechanisms
Clinical Causes
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Inadequate ventilation
Airway obstructionHypoventilation
Endobronchial intubation
Patients with increased A-a gradient
Pre-existing lung disease
Pneumothorax
Pulmonary oedema
AspirationAtelectasis
Pulmonary embolism
Low cardiac output
Clinical Causes
P i
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Check anaesthetic machine
O2 analyser & alarms
Adequate Ventilation (esp. tidal volume)
Monitor & adjust FiO2 High normal range tidal volume
Caution with spontaneous ventilation in lung disease
Prevention
Manifestations
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Pulse Oximetry
Malfunction can occur: check waveform &
probe positionHypothermia
Poor peripheral circulation
Artefacts: diathermy, motion, ambient lighting
Cyanosis
Dark blood in surgical field
Late signs
bradycardia ,
myocardial ischaemia & dysrrhythmias,
hypotension and
cardiac arrest
Management
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Assume low SpO2 = hypoxaemia
Increase FiO2Verify FiO2 increases
Check pulse, BP
Check EtCO2 & pulse oximeter
Hand ventilate - assess lung compliance, give large TV
Check chest movements & auscultate chest
Exclude endobronchial intubation
ABGs Posture sitting up
Management
Verify Pulse Oximeter
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Assess signal amplitude Check waveform
Check position
Correlate reading with diathermy
Shield probe Change site
Verify Pulse Oximeter
Persistent hypoxemia
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Extra-Pulmonary
Low cardiac output
Intracardiac shunting in CHD
yp
causes
Pulmonary Pneumothorax - consider CXR
Aspiration
Massive atelectasis
Pulmonary embolism Aspiration of foreign body
Acute pulmonary oedema
P i t t h i t
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Use aggressive pulmonary toilet
Suction ETT
Consider bronchoscopy
Consider addition of PEEP
Restore circulating blood volume
Maintain CO and Hb levels (Hb >100g/L)
Consider inotropes
Persistent hypoxemia management
Persistent hypoxemia Mgt. Contd.
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Inform surgeons (earlier if appropriate)
Check retractors
Transfer to supine position
Terminate surgery ASAP
Investigations in PACU
Incl. CXR, ABGs
Arrange transfer to ICU
Persistent hypoxemia Mgt. Contd.
Awake patient
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Look for cause
Inadequate Ventilation
airway,
depressed VA
Pulmonary and extra-pulmonary
Also diffusion hypoxaemia,
laryngospasm,
inadequate reversal,
Shivering
Management
High flow O2 - CPAP - re-intubation
Drug reversal relaxants, opioids
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Hypercapnia
I t th i CO i t bl
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In most other cases
(where the minute volume would otherwise be adequate),
the treatment, if any is required, is still simply to increase the
minute volume
In most cases, the increase CO2 per se is not a problem
(exception e.g. neurosurgery)
In most cases, the cause is simply hypoventilation
(i.e. V < ~100mls/min/kg)
Situations requiring specific Rx
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Malignant hyperpyrexia
thyroid storm
circuit problems ( = increased FiCO2)
exhausted soda lime
expiratory valve failure
inadequate fresh gas flow in partial rebreathing circuits
excessive circuit dead space (i.e. on patient side of Y-piece)
S tuat o s equ g spec c
(other than simply increasing ventilation)
MH Is it?Isnt it?
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Unfortunately, signs with higher +ve predictive values are not
available immediately
(e.g. increased CK, myoglobinuria, worsening metabolicacidosis)
Immediately available clinical signs are non-specific
(e.g. increased HR)
Beware masseter spasm, rigidity of other muscle groups, mottled
skin, increased TC (late sign)
Keep MH in mind if CO2 continues to rise despite adequate
minute ventilation
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Increased CO2 production
Decreased CO2 excretion
Increased CO2 delivery to lungs
Causes of hypercapnia
Increased CO2 production
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Increased temperature (including MH, Sepsis)
Hyperthyroidism (including thyroid storm)
Exogenous (e.g. CO2 pneumoperitoneum)
NaHCO3 administration
Tourniquet release
Shivering
Convulsions
Compensation for metabolic alkalosis
Increased CO2 production
Decreased CO excretion
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IPPV : inadequate ventilator settings Spontaneous ventilation : respiratory depressant drugs
Partial airway obstruction
Altered respiratory mechanics
e.g. decreased compliance due to
pneumoperitoneum,
obesity,
Trendelenburg
Decreased CO2 excretion
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Increased cardiac output
R to L shunt
Increased CO2 delivery to the lungs
Management
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Ensure adequate oxygenation
Ensure adequate ventilation
Check FiO2
Blood gases to confirm capnography Consider secondary causes, especially those requiring
specific Rx (MH, thyroid storm etc.)
Treat complications of hypercapnia
g
Ensure adequate ventilation
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Check airway (e.g. is LMA seated well ? )
Check circuit (e.g. ventilate manually any obstruction ? )
Check minute ventilation (e.g. ventilator settings or spirometry)
Ensure adequate ventilation
If FiCO2 raised:
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Check valves (e.g. expiratory valve stuck open)
Check if soda lime exhausted
Check if fresh gas flow inadequate
Complications of hypercapnia
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Hypertension, tachycardia
Pulmonary hypertension
Arrhythmias
Complications of hypercapnia
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Hypocapnia
Hypocapnia
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No ETCO2
Low ETCO2
Timing ?
Never or suddenly absent
Concurrent events ?
Surgical,
anaesthetic or
change in position
Timing ?
Always low,suddenly low or
falling
Concurrent events ?
No ETCO2
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Oesophageal intubation Accidental extubation
Disconnection
Equipment failure
has the machine and monitor been checked prior to induction?
Cardiac arrest
2
Low ETCO
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Airway Circuit
Ventilation
Gas exchange
Decreased production
Low ETCO2
Airway
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Oesophageal intubation
Accidental extubation
Airway
Circuit
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Air entrainment (leak)
Dilution with circuit gases (sampling problem)
Ventilation
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Ventilation settings
Overenthusiastic hand ventilation
Metabolic acidosis spontaneously ventilating patient
Ventilation
Gas Exchange
7/29/2019 Critical Incidentsduring Perioperative Period Sept 2011
104/106
104
Pulmonary embolismAir
Clot
Fat
Decreased cardiac output/arrest
Severe hypotension
Gas Exchange
Decreased Production
7/29/2019 Critical Incidentsduring Perioperative Period Sept 2011
105/106
105
Hypothermia
Hypothyroidism
Decreased Production
7/29/2019 Critical Incidentsduring Perioperative Period Sept 2011
106/106
Thank you !