Answer:

The causes of intraoperative wheezing and increased airway pressure include the following:

• Mechanical obstruction of endotracheal tube

  • Kinking

  • Secretions or blood

  • Overinflation of tracheal tube cuff

• Inadequate depth of anesthesia

  • Active expiratory efforts

• Pulmonary edema

• Pneumothorax (especially consider in a patient with emphysema and blebs)

• Aspiration pneumonitis

• Pulmonary embolism

• Endobronchial intubation

• Acute asthmatic attack

• Anaphylaxis

Anaphylaxis is a rare event but should be considered in all patients with intraoperative bronchospasm. The most common causes of intraoperative allergies include neuromuscular blocking drugs (NMBDs), latex, and antibiotics. Cardiovascular (hypotension) and cutaneous (flushing, urticaria) manifestations along with bronchospasm are the most common presenting signs of anaphylaxis during anesthesia. In the setting of bronchospasm with hypotension, even without cutaneous signs, anaphylaxis is high on the differential. Administration of likely inciting agents should cease; epinephrine 5 to 10 µg, diphenhydramine, and steroids should be given. An infusion of epinephrine may be necessary. A tryptase level should be sent to confirm the diagnosis, and the patient should be notified in writing of the potential reaction so that follow-up allergy testing can be obtained.

• Hepner DL, Castells MC. Anaphylaxis during the perioperative period. Anesth Analg. 2003;97:1381-1395.
• Hines RL, Marschall KE, eds. Stoelting’s Anesthesia and Co-existing Disease. 7th ed. Philadelphia, PA: Elsevier; 2018:22.
• Woods BD, Sladen RN. Perioperative considerations for the patient with asthma and bronchospasm. Br J Anaesth. 2009;103(suppl 1):i57-i65.