critical incidentsduring perioperative period sept 2011

7/29/2019 Critical Incidentsduring Perioperative Period Sept 2011

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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



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Kinked

Misplaced

OesophagealEndobronchial

Obstructed

Sputum, blood

Cuff herniation

Too small


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



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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


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



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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)


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


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Pulmonary embolismAir

Clot

Fat

Decreased cardiac output/arrest

Severe hypotension

Gas Exchange

Decreased Production


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Hypothermia

Hypothyroidism

Decreased Production


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Thank you !

critical incidentsduring perioperative period sept 2011

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