IntroductionPulmonary collapse after intubation is common, and it is caused by a variety of factors.Case PresentationA 21-year-old man presented at our operation room to undergo an appendectomy. Except for a history of cigarette smoking, his history was negative. Anesthesia was induced with 100% oxygen and sevoflurane, remifentanil infusion, and propofol. Neuromuscular block was obtained with rocuronium. The tip and cuff of a tracheal tube were lubricated with a topical metered-dose of 8% Lidocaine pump spray. After intubation, SPO2 suddenly decreased. The chest x-ray revealed right upper lobe atelectasis. Fiber optic bronchoscopy showed that a large amount of yellow sticky mucus had been secreted into the right main bronchus.ConclusionsIn Japan, 8% Lidocaine pump spray contains menthol and ethanol as additives. These additives, particularly menthol, might have led to excessive mucus production, although we did not analyze the mucus secretion.