Bronchoscopy and nitrous oxide pollution.

The purpose of the investigation was to assess the extent of nitrous oxide pollution during bronchoscopy (rigid ventilation bronchoscope) and further to elucidate the possible reduction in air pollution during local scavenging of leaking gas by a suction catheter placed in the pharynx. The study included 14 adult patients. The leakage of anaesthetic gas was 11.4 +/- 3.2 l min-1 and the median value of the nitrous oxide concentration in the breathing zone of the endoscopist was greater than 300 ppm. Air pollution could not be reduced significantly by scavenging with a suction catheter. The use of inhalation anaesthetics is therefore inadvisable during bronchoscopy in adults unless sufficient anaesthetic scavenging can be established. Other ways of reducing air pollution are discussed and the use of total intravenous anaesthesia or local anaesthesia is advocated.