The primary goals in managing bronchospasm are to reverse the bronchospasm and prevent hypoxemia. If bronchospasm occurs, immediately increase oxygen concentration to 100% and initiate manual bag ventilation to assess pulmonary compliance and identify causes of high circuit pressure.
Inhaled β2-agonists are the first-line treatment for rapid bronchospasm relief, as they activate β2-adrenergic receptors on airway smooth muscles. Ipratropium can be used alongside β2-agonists to reduce reflex-induced bronchoconstriction, particularly in life-threatening cases.
Deepening anesthesia may be necessary, as inadequate depth can trigger bronchospasm during endotracheal tube (ETT) placement or airway manipulation. Increasing the concentration of inhalational anesthetics, except desflurane (due to its airway irritant properties), is also effective. In cases of bronchospasm where ventilation is severely compromised, deepening anesthesia with an inhalational agent can be challenging. Adjunctive treatments include IV lidocaine, IV propofol, subcutaneous (SC) terbutaline, SC or IV epinephrine, and a nebulized β-agonist. When ventilation is significantly impaired, epinephrine should be administered in small titrated IV doses (10 to 50 mcg, escalating as needed) or 0.3 mg subcutaneously when IV access is not available, and anesthesia should be deepened with an IV agent until effective ventilation is restored.
Mechanical ventilation should focus on preventing and correcting hypoxemia, reducing tidal volumes to avoid high peak airway pressures and barotrauma, and tolerating hypercapnia if oxygenation is adequate. A longer expiratory time is recommended to allow full exhalation, reducing the risk of breath stacking and intrinsic PEEP, which can increase intrathoracic pressure and lead to hypotension.
| Step | Action |
|---|---|
| Immediate | Increase oxygen concentration to 100% and begin manual bag ventilation to assess pulmonary compliance and identify causes of high circuit pressure |
| First-line drug | Inhaled β2-agonists, which act on β2-adrenergic receptors on airway smooth muscle |
| Anticholinergic adjunct | Ipratropium alongside a β2-agonist to reduce reflex-induced bronchoconstriction, particularly in life-threatening cases |
| Deepen anesthesia | Increase the inhalational agent concentration — except desflurane, because of its airway irritant properties |
| Adjunctive drugs | IV lidocaine, IV propofol, subcutaneous terbutaline, subcutaneous or IV epinephrine, and a nebulized β-agonist |
| Ventilation severely impaired | Give epinephrine in small titrated IV doses (10 to 50 mcg, escalating as needed; 0.3 mg SC if no IV access) and deepen anesthesia with an IV agent until effective ventilation is restored |
| Ventilator settings | Reduce tidal volumes to avoid high peak airway pressures and barotrauma; tolerate hypercapnia if oxygenation is adequate |
| Expiratory time | Lengthen it to allow full exhalation, reducing breath stacking and intrinsic PEEP, which raise intrathoracic pressure and can cause hypotension |
