Hazards of anaesthetic scavenging: case reports and brief review.

Two cases are presented of misadventure occurring in association with the use of anaesthetic scavenging equipment. The first case demonstrates how easily the scavenging line linking the venting port of a mechanical ventilator to the scavenging interface can become accidentally obstructed. The second case suggests that the proper use of scavenging equipment will effectively eliminate any possibility of recognising by smell an accidental overdose of volatile anaesthetic agent. Previous reports of scavenging hazards are briefly reviewed. It is concluded from this review that scavenging suction should be 'low-vacuum', that a relief valve must be included in the scavenging pathway proximal to any site of potential obstruction, and that the appearance and function of a scavenging interface must be simple and immediately obvious.