title: "Pseudo auto-PEEP"? A new cause for discrepancy between the end-expiratory occlusion plateau pressure and airway opening pressure.
abstract: The purpose of this study is to describe an unexpected degree of differences between expiratory occlusion plateau pressure (EPO) and airway opening pressure (Pawo) measured level of intrinsic positive end-expiratory pressure above externally applied (auto-PEEP) that was found in six critically ill patients. In six patients (ten studies), the presence and degree of auto-PEEP found during the EPO maneuvers was not confirmed by Pawo measurements. In five studies, flow tracings showed prolonged near zero flow toward end expiration and a slow rise to plateau during the EPO maneuver. Because of the static nature of the EPO determination, a rise in pressure could conceivably be caused by the presence of subcutaneous or mediastinal emphysema and retrograde flow across the airway defect during exhalation. We suggest another cause for auto-PEEP-dynamic hyperinflation from extrapulmonary flow limitation.
authors: Division of Surgical Critical Care, Albany Medical College, NY 12208.
authors: Z
authors: Z
authors: Bilen
authors: I L
authors: IL
authors: Cohen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D011175:Positive-Pressure Respiration; D012123:Pulmonary Ventilation; D012128:Respiratory Distress Syndrome / Q000503:physiopathology* / Q000628:therapy