How do you manage intraoperative bronchospasm in a patient with a history of asthma or Chronic Obstructive Pulmonary Disease (COPD)?

Intraoperative Bronchospasm Management

Immediately administer inhaled beta-2 agonist bronchodilators (albuterol 5-15 puffs via MDI with spacer or 2.5 mg nebulized) while deepening anesthesia and ensuring 100% oxygen delivery, as this combination provides the most rapid and effective relief of intraoperative bronchospasm in patients with asthma or COPD. 1, 2

Immediate Management Steps

First-Line Interventions

• Deepen anesthesia immediately to reduce airway hyperreactivity, as inadequate depth is a common trigger for bronchospasm 3
• Administer 100% oxygen to maintain saturation ≥90% and reduce risk of hypoxemia-related complications 3
• Remove potential triggers including surgical stimulation if possible 3

Bronchodilator Administration

For intubated patients:

• Administer 5-15 puffs of albuterol MDI (90 mcg/puff) through a spacer device (e.g., Aerovent) directly into the endotracheal tube 2
• Start with 5 puffs and titrate upward; studies show 10 puffs (900 mcg total) provides optimal bronchodilation in mechanically ventilated patients, with resistive pressure decreasing from 25.1±7.2 to 19.0±4.4 cm H₂O 2
• Alternatively, nebulize 2.5 mg albuterol (one full vial of 0.083% solution) through the endotracheal tube over 5-15 minutes 1

For patients with LMA:

• Use a valved holding chamber (VHC) rather than a simple adapter, as VHC increases drug delivery efficiency to 6.3% versus 0% with adapter alone 4
• Actuate the MDI during exhalation to maximize delivery efficiency 4
• Expect onset of bronchodilation within 11±4 minutes 5

Alternative Bronchodilator: Ipratropium Bromide

• Consider ipratropium bromide 120 mcg aerosolized through the endotracheal tube if beta-2 agonists are contraindicated or ineffective 5
• Provides significant reduction in peak inspiratory pressure within 5 minutes, with peak effects at 120 minutes 5
• Particularly useful as it does not cause tachycardia, unlike beta-2 agonists 5

Monitoring and Assessment

Ventilator Parameters to Track

• Monitor peak inspiratory pressure (PIP) and pause pressure to calculate resistive pressure (PIP - pause pressure) 2
• A PIP to pause gradient >15 cm H₂O indicates significant bronchospasm requiring treatment 2
• Expect resistive pressure to decrease within 5 minutes of effective bronchodilator administration 5, 2

Clinical Signs

• Assess for wheezing, increased airway resistance, and decreased oxygen saturation 3
• Monitor for cardiovascular instability including tachycardia or hypotension 3

Special Considerations for Asthma Patients

Preoperative Optimization (Prevention)

• Premedicate with bronchodilator before any procedure in asthmatic patients, as this prevents postoperative FEV₁ decline 3, 6
• Consider atropine pretreatment to attenuate lignocaine-induced bronchoconstriction, as lignocaine may paradoxically cause bronchospasm in asthmatics 3
• Use sedation with extreme caution in asthmatic patients, as the procedure itself may exacerbate bronchoconstriction 3

Intraoperative Technique

• Secure the airway with general anesthesia rather than using deep sedation without airway control, particularly for procedures that may mechanically compromise the airway 3, 6
• Consider regional anesthesia or peripheral nerve blocks for superficial procedures to avoid airway manipulation entirely 3, 6

Special Considerations for COPD Patients

Risk Stratification

• Patients with severe COPD (FEV₁ <40% predicted and/or SaO₂ <93%) have a 5% complication rate versus 0.6% in those with normal lung function 3
• Check arterial blood gas tensions preoperatively in severe COPD to identify baseline CO₂ retention 3

Oxygen and Sedation Management

• Avoid sedation if pre-procedure arterial CO₂ is elevated, as both oxygen supplementation and sedation may worsen hypercapnia 3
• Administer supplemental oxygen with extreme caution in CO₂ retainers 3

Refractory Bronchospasm Management

Escalation of Therapy

• If initial bronchodilator therapy fails, increase albuterol to 30 cumulative puffs (2700 mcg), though doses beyond 15 puffs rarely provide additional benefit 2
• Consider intravenous corticosteroids (e.g., methylprednisolone) for persistent bronchospasm, though onset is delayed 7
• For patients on oral corticosteroids within 6 months, administer 100 mg hydrocortisone IV during the surgical period 6

Ventilator Adjustments

• Use protective one-lung ventilation with tidal volume 6 mL/kg predicted body weight and PEEP 5-8 cm H₂O if applicable 8
• Ensure full reversal of neuromuscular blockade before extubation 3

Extubation Strategy

• Extubate while fully awake unless medically contraindicated, as this reduces risk of laryngospasm and recurrent bronchospasm 3, 6
• Place patient in semi-upright position for extubation and recovery 6
• Verify adequate spontaneous ventilation and airway reflexes before extubation 3

Critical Pitfalls to Avoid

Paradoxical Bronchoconstriction

• Be aware that albuterol itself can rarely cause paradoxical bronchoconstriction (documented in case reports), manifesting as worsening stridor and bronchospasm within 30 minutes of administration 7
• If bronchospasm worsens after albuterol, discontinue immediately and consider alternative bronchodilators like ipratropium 5, 7

Medication Toxicity

• Monitor for cardiovascular toxicity with high-dose beta-2 agonists, including hypotension (≥20 mm Hg decrease in systolic BP) and tachycardia 2
• Titrate bronchodilator dose to clinical effect rather than using fixed protocols 2

Differential Diagnosis Errors

• Consider non-bronchospasm causes of increased airway pressure: endotracheal tube malposition, aspiration, inadequate anesthesia depth, or mechanical obstruction 3
• If symptoms arise from a single organ system without tryptase elevation, an allergic reaction is less likely 3

Temperature Management

• Avoid hypothermia in the postoperative period, as it can trigger bronchospasm 6
• Maintain normothermia throughout the perioperative period 9