Abstract
Pulmonary aspiration occurred in 16 out of 65 patients (24.6%) undergoing fibre-endoscopic examinations of the upper gastrointestinal tract under intravenous sedation, but it was rarely followed by serious complications. Aspiration was found to occur under sedation with diazepam alone, diazepam with atropine, and with chlormethiazole. The most important factors contributing to aspiration are the local pharyngeal anaesthesia and the mechanical interference of the fibrescope with laryngeal closure and swallowing. The patient is also at risk of aspiration after completion of the procedure and should remain recumbent until the local anaesthesia has worn off.