Autocycling and increase in intrinsic positive end-expiratory pressure during mechanical ventilation

Modern ventilators are complicated electronic instruments with microprocess ors and software, with the possibility of technical errors and problems suc h as autocycling. Despite autocycling being recognized as a problem in text books and reviews, there are few reports about autocycling in the literatur e. We report a case where a sudden increase in respiratory frequency due to autocycling resulted in a dangerous increase in intrinsic positive end-exp iratory pressure (intrinsic PEEP, PEEPi). We think our case illustrates tha t autocycling does occur, but that the exact underlying mechanism may be ha rd to document and understand for clinicians. To remedy this situation, we suggest that manufacture-independent technical expertise should be establis hed to evaluate incidents and suggest improvements.