Fault in a Selectatec manifold resulting in awareness

The Selectatec Vaporising System is a quick change system consisting of anaesthetic vaporisers of the Tec 3 and Tec 4 models and the compatibility manifold block on which these are seated on the anaesthetic machine backbar. There have been reports of difficulties with the seating and locking of the vaporisers which can cause a leak and failure of vapour delivery. The Faculty of Anaesthetists, Royal Australasian College of Surgeons (now Australian and New Zealand College of Anaesthetists) issued a hazard alert in March 1991 drawing attention to this potential fault. We present two cases of awareness associated with failure of internal seals within a Selectatec compatibility manifold block which did not have a detectable leak.