Severe Bronchospasm

Question 1

What are the signs of severe bronchospasm?

Answer 1

“Tight” bagging progressing to difficulty to ventilate

High airway pressures

Decreased expiratory tidal volume

Upsloping expiratory capnograph, progressing to markedly reduced EtCO2

Wheeze progressing to silent chest

Desaturation

Tachypnoea, tachycardia, hypotension (dec VR from inc ITP)

Question 2

When is bronchospasm most likely to occur?

Answer 2

Severe bronchospasm most commonly occurs immediately after intubation

If delayed onset - be suspicious of another diagnosis

Question 3

What are differential diagnoses for bronchospasm?

Answer 3

Circuit - kink, HME filter block, valve problem

Airway - kinked/blocked, malposition

Patient - light (biting, fighting ventilator), laryngospasm, anaphylaxis, aspiration, pneumothorax, pulmonary oedema

Question 4

Outline immediate an immediate management strategy for severe bronchospasm

Answer 4

1. Exclude airway/circuit problems - if in doubt, replace the airway
2. Call for help
3. Hand ventilate with 100% O2 and deepen anaesthesia with Propofol 2-5mL bolus; or consider change to Sevoflurane
4. Place in-circuit nebuliser or metered dose adaptor distal to HME filter and deliver Salbutamol
5. 5mg Salbutamol in neb, 500mcg Ipratropium in neb, 6-8 puffs of MDI and rpt q3m (or Glycopyrrolate 400mcg IV)
6. Monitor response on EtCO2, airway pressure, SpO2
7. If unresponsive - Salbutamol IV bolus 250mcg slowly (5-10mcg/kg in kids), then infusion OR
8. Aminophylline 5mg/kg over 15mins
9. If in extremis - Adrenaline IV 0.1-10mcg/kg - will cause tachycardia and hypertension and risk of arrythmia OR
10. Ketamine 1mg/kg then infusion OR
11. Magnesium 2gm over 5mins

Question 5

Discuss an appropriate ventilation strategy for a pt with severe bronchospasm

Answer 5

Aim is long expiratory phase and minimal PEEP to reduce hyperinflation

Slow RR

Prolonged expiratory time (I:E ratio 1:4)

Permissive hypercapnia

Intermittent disconnection from ventilator to prevent autoPEEP

Question 6

What are the drug choices and doses for managment of severe bronchospasm

Answer 6

• Propofol 2-5mLs to deepen sedation
• Sevoflurane
• Salbutamol 5mg neb, 6-8puff MDI, 250mcg IV bolus (5-10mcg/kg in kids), infusion 5-20mcg/min
• Aminophylline 5mg/kg bolus, infusion 0.5mg/kg/hr
• Adrenaline 0.1-10mcg/kg bolus (10mcg-100mcg), infusion 0.1mcg/kg/min
• Ketamine 1mg/kg
• Magnesium 2gm over 5mins
• Heliox
• Hydrocortisone 1-2mg/kg (100mg IV)

Question 7

What monitoring may be useful in a pt with severe bronchospasm?

Answer 7

Standard monitoring (ECG, SpO2, EtCO2 etc)

Arterial line for serial ABGs

Question 8

After the episode of severe bronchospasm settles - what next?

Answer 8

• Continue IV hydrocortisone (100mg IV)
• Decide whether it is appropriate to extubate - transfer to ICU vs extubating deep in OT
• Avoid use of anticholinesterase and histamine releasing drugs and NSAIDs
• Monitor K+ closely
• Document
• Exclude any possible differential diagnoses (anaphylaxis, aspiration)
• Will require medical review