The Laryngeal-closure Reflex and Nitrous Oxide-Oxygen Analgesia

Abstract

Nitrous oxide-oxygen sedation is in daily use in dental practice, following the pioneering work of practitioners such as Langa.1 With this technique, nitrous oxide is administered in analgesic concentrations, together with oxygen, using special apparatus with built-in oxygen fail-safe devices.2 Although no fatality or severe complication from this technique has been reported, it has been suggested by Pleasauts3 that the pharyngeal protective reflexes may be deminished. If this is so, then material from the oral cavity could be inhaled during dental treatment using nitrous oxide—oxygen sedation, which is an inherently dangerous situation. This study was undertaken to see whether nitrous oxide-oxygen sedation caused any depression of the pharyngo-laryngeal reflexes.