Safety of fibreoptic endoscopy: analysis of cardiorespiratory events.

Cardiorespiratory function during upper gastrointestinal endoscopy and colonoscopy was studied prospectively in 164 patients. Cardiorespiratory events, which were defined as oxygen saturation < 90 per cent, electrocardiographic changes, heart rate < 50 or > 100 beats/min and systolic blood pressure < 100 mmHg, occurred in 111 patients. In 24 of these, changes were attributed solely to intravenous sedation. In the remaining 140 patients, events were noted in 34 (52 per cent) of 66 upper gastrointestinal endoscopies and during 53 (72 per cent) of 74 colonoscopies. One patient suffered a myocardial infarction during colonoscopy. Although cardiorespiratory events were common (111 of 164; 68 per cent), the actual morbidity rate was low (one of 164; 0.6 per cent). Cardiorespiratory events were significantly more common in patients with a history of cardiac disease for both upper gastrointestinal endoscopy and colonoscopy (overall chi 2 = 7.41, 1 d.f., P < 0.05) and more common for oesophageal dilatation than for diagnostic endoscopy (chi 2 = 5.56, 1 d.f., P < 0.05). It is recommended that patients with a history of cardiac problems undergoing upper gastrointestinal endoscopy or colonoscopy and all those requiring therapeutic endoscopy should be monitored carefully to allow early detection of cardiorespiratory events, and that oxygen should be administered routinely.