Mechanical ventilation: simplifying the terminology.

Abstract

There is presently considerable ambiguity and confusion relating to ventilator terminology. This can be eliminated using a simple approach, visualising mechanical ventilation as an inspiratory pump, and defining trigger, limit, and cycling in this context. The trigger is the signal that starts a breath by opening the inspiratory valve, the limit is the factor which controls the way gas flows into the lung, and the cycle is the signal that stops the breath by closing the inspiratory valve and opening the expiratory valve. By identifying these three basic parameters, one can precisely dissect and interpret any of the vast ventilatory terminology.