An anesthetist is posed with puzzling case when a child scheduled for diagnostic upper endoscopy suffers bronchospasm during the procedure. Can you identify why the bronchospasm occurred? A 4-year-old child, 24 kg, is scheduled for a diagnostic upper endoscopy. Her major complaint is intermittent vomiting of unknown cause. Her medical history is significant for asthma.

She takes nebulized albuterol, but only when needed. On physical exam, you find nothing wrong and her lungs are clear to auscultation. On the day of surgery, she is treated prophylactically with 2.5 mg nebulized albuterol and oral midazolam is given with good effect. At the patient’s request, an inhalation induction is performed using sevoflurane (up to 8% inhaled concentration) and 50% N 2 O in oxygen. The patient falls asleep and an oral airway is inserted and positive-pressure ventilation is instituted by bag-mask…