II. Indications
- Pulmonary condition with widespread alveolar collapse
-
Adult Respiratory Distress Syndrome (ARDS)
- PEEP increases Lung Compliance
- PEEP decreases intrapulmonary shunting
- Increases PO2 and allows lower FIO2 below 60%
- May increase dead space ventilation
- Overdistends normal lung
-
Pulmonary Edema
- PEEP allows decrease in FIO2 below 60%
- PEEP may increase extravascular lung water
III. Indications: Disproved uses of PEEP
- Localized Lung Disease (e.g. lobar Pneumonia)
- PEEP may worsen Hypoxemia
- Overdistends normal lung
- Directs Blood Flow to diseased lung
- PEEP not recommended
- Unless selectively applied to diseased lung
- PEEP may worsen Hypoxemia
- Prophylactic PEEP
- PEEP does not reduce ARDS Incidence
- Routine PEEP
- PEEP does not appear indiscriminately beneficial
- Mediastinal Bleeding
- PEEP does not protect against mediastinal bleeding
IV. Physiology
- PEEP maintains small end-expiratory pressure
- Helps to prevent alveolar collapse
- Promotes alveolar-capillary gas exchange
- Increases lung function parameters
- Increases Functional Residual Capacity (FRC)
- Increases Cardiac Output with low airway pressures
- May result in increased Oxygen Delivery
V. Dosing: PEEP Table (ARDSNet, Low PEEP Version)
- Usual PEEP setting: 5 to 10 cm H2O
-
ARDS-NET PEEP Adjustment based on FIO2 for mechanically ventilated patients
- PEEP Levels >15 cm H2O are rarely required and are associated with complications (Barotrauma)
- Strategy listed here correlates to the ARDSNet lower PEEP version
- FIO2: 0.3
- PEEP: 5 cm H2O
- FIO2: 0.4
- PEEP: 5 to 8 cm H2O
- FIO2: 0.5
- PEEP: 8 to 10 cm H2O
- FIO2: 0.6
- PEEP: 10 cm H2O
- FIO2: 0.7
- PEEP: 10 to 14 cm H2O
- FIO2: 0.8
- PEEP: 14 cm H2O
- FIO2: 0.9
- PEEP: 14 to 18 cm H2O
- FIO2: 1.0
- PEEP: 18 to 24 cm H2O
- PEEP Levels >15 cm H2O are rarely required and are associated with complications (Barotrauma)
VI. Complications
- Decreased Cardiac Output
- Associated with higher airway pressures
- Associated with decreased ventricular filling
- Barotrauma
- Fluid Retention
- Intracranial Hypertension
VII. References
- Marino (1991) ICU Book, Lea & Febiger, p. 375-9