Positive end expiratory pressure

Positive end expiratory pressure (PEEP) is the amount of pressure that remains at the end of the expiratory phase which can be set in mechanically ventilated patients.

Benefits of PEEP

• Increased FRC
• Prevents closing of alveoli, thereby reducing airway opening pressure
• Increase Palv, making West's zone move more caudally, thereby reducing physiologic shunt from Zone 3

Consequences of PEEP

• Barotrauma/volutrauma: Increased peak airway pressure at high PEEP
• Decreased venous return from IVC due to increased thoracic pressure
• Decreased pulmonary blood flow
  • In patients with pulmonary hypertension, can worsen R heart strain
• Elevation in ICP; decrease in cerebral perfusion pressure
  • CPP = MAP - ICP