A study of the incorrect use of ventilator disconnection alarms.

Pressure-sensitive ventilator disconnection alarms may fail to function correctly when used with discharging compliance ventilators such as the Manley Blease. The increase in gas flow on disconnection generates raised pressure owing to the resistance provided by components of the breathing system. Thirty-four anaesthetists, who were unaware of the nature of the survey, were observed to see if previous recommendations for the correct adjustment of the ventilator alarm were being followed. It was found that 77% of alarms were incorrectly adjusted and would not have alarmed in the event of a true disconnection occurring.