A three-year-old boy presents for an emergent repair of an open distal radius fracture. His medical history is significant for asthma, obesity, and passive tobacco smoke exposure. He has had a runny nose and a productive cough over the past few days. Vital signs are notable for a temperature of 99.7 F and an oxygen saturation of 95%. Which of the following interventions is MOST likely to decrease his risk of a perioperative respiratory event?