Auto-PEEP: an impediment to weaning in the chronically ventilated patient

Auto-positive end expiratory pressure (auto-PEEP) is a physiologic event that is a recently recognized phenomenon common to mechanically ventilated patients. Auto-PEEP occurs when forces exist that limit expiration and the subsequent elimination of positive pressure from the lungs. If positive pressure is retained, a potential reduction in cardiac output and increase in complications from barotrauma arise. Because of possible physiologic problems associated with it, auto-PEEP can potentially interfere with weaning from mechanical ventilation. Nursing measures that can reduce the effect of auto-PEEP during weaning are centered on improving the inspiratory/expiratory flow patterns. These efforts include manipulating mechanical ventilator settings and reducing causes of increased respiratory rates (e.g., pain and anxiety). Since auto-PEEP was only recently identified as a potential impediment to weaning from mechanical ventilation, the nurse must be aware of the need to assess for the presence of auto-PEEP in these patients.