What is the first line treatment for intraoperative (intraop) bronchospasm?

Management of Intraoperative Bronchospasm

The first-line treatment for intraoperative bronchospasm is intravenous epinephrine (50-100 μg) if no other vasopressors or bronchodilators have been given, along with inhaled beta-agonists such as albuterol. 1

Initial Management Algorithm

Step 1: Recognition and Assessment

• Identify bronchospasm: wheezing, increased airway pressures, difficulty ventilating
• Assess severity:
  • Moderate (Grade II): Increased airway resistance but adequate ventilation
  • Severe (Grade III): Life-threatening with significant hypoxemia
  • Critical (Grade IV): Respiratory arrest

Step 2: Immediate Interventions

1. For Grade II (moderate) bronchospasm:

   • IV epinephrine 20 μg 1
   • If unresponsive after 2 minutes, administer 50 μg 1
   • Administer crystalloid 500 mL as rapid bolus 1

2. For Grade III (severe) bronchospasm:

   • IV epinephrine 50 μg if no other vasopressors/bronchodilators have been given 1
   • If unresponsive to other vasopressors/bronchodilators, administer 100 μg 1
   • If unresponsive after 2 minutes, administer 200 μg 1
   • Administer crystalloid 1 L as rapid bolus 1

3. For Grade IV (respiratory arrest):

   • Follow local advanced life support guidelines including IV epinephrine 1 mg 1
   • Initiate cardiac compressions if inadequate cardiac output 1

Step 3: Additional Bronchodilator Therapy

• Administer inhaled beta-agonists (albuterol/salbutamol) via the breathing circuit 2, 3

  • 2.5-5 mg nebulized through the endotracheal tube 2
  • For MDI delivery: 5-10 puffs (90 μg per puff) through a spacer device 4

• Consider adding ipratropium bromide if inadequate response to beta-agonists 2, 5

  • 120 μg aerosolized through endotracheal tube 5

Management of Refractory Bronchospasm

If bronchospasm persists after 10 minutes:

1. Escalate epinephrine therapy:

   • Double the bolus dose 1
   • Consider epinephrine infusion (0.05-0.1 μg/kg/min) 1
   • Start epinephrine infusion if more than three boluses have been administered 1

2. Additional interventions:

   • Consider IV bronchodilators (e.g., ketamine, IV salbutamol) 1
   • Deepen anesthesia with volatile anesthetics if hemodynamically stable 1
   • Ensure adequate hydration (up to 20-30 mL/kg) 1

Special Considerations

• For patients on beta-blockers:

  • Bronchospasm may be more severe and refractory to treatment 1
  • Consider IV glucagon (1-2 mg) 1

• For anaphylaxis-induced bronchospasm:

  • Follow anaphylaxis protocol with higher doses of epinephrine 1, 6
  • After adequate epinephrine and fluid resuscitation, consider IV antihistamines 1

• For pediatric patients with URI:

  • Consider prophylactic inhaled salbutamol before anesthesia in children under 6 years 1
  • Dose: 2.5 mg for children <20 kg, 5 mg for children >20 kg 1

Monitoring and Follow-up

• Monitor oxygen saturation, end-tidal CO2, airway pressures
• Observe for at least 6 hours after resolution of symptoms 1
• Consider tryptase testing if anaphylaxis is suspected 1

Pitfalls to Avoid

1. Delayed administration of epinephrine - Don't hesitate to use epinephrine for severe bronchospasm; delays increase morbidity and mortality
2. Inadequate fluid resuscitation - Ensure sufficient volume replacement, especially in anaphylaxis-related bronchospasm 1
3. Relying solely on inhaled beta-agonists - For severe cases, IV epinephrine is essential 1
4. Overlooking anaphylaxis - Consider anaphylaxis in any case of sudden bronchospasm, especially if accompanied by hypotension or urticaria 6
5. Inadequate dosing of MDI medications - When using MDI in ventilated patients, higher doses (up to 15 puffs) may be needed for effect 4

By following this algorithm and avoiding common pitfalls, intraoperative bronchospasm can be effectively managed to minimize morbidity and mortality.