Autocycling During Noninvasive Positive Pressure Ventilation Producing a Prolonged Severe Apnea and Syncope.

Autocycling is a form of patient-ventilator asynchrony that can occur during mechanical ventilation. In the case described, autocycling during noninvasive ventilation led to severe hyperventilation and subsequently produced a prolonged central apnea that resulted in syncope. This case represents the first description of a severe adverse event from autocycling during noninvasive ventilation.