Intrinsic PEEP: a cause of inspiratory muscle ineffectivity.

Intrinsic PEEP has been described as an inspiratory threshold load to the inspiratory muscles that could increase the work of breathing. We report a patient who presented ineffective inspiratory efforts to trigger the ventilator; when we applied PEEP in similar amounts of measured intrinsic PEEP, his inspiratory efforts became able to trigger the ventilator, suggesting that the inspiratory load was alleviated.