To effectively manage PEEP settings, consider the following practical guidelines:
Normal PEEP Parameters: Standard PEEP levels are 3-5 cm H2O for routine use (5 cm H2O is the usual intraoperative default, and zero PEEP is now discouraged), rising to 8-10 cm H2O or more for laparoscopy, Trendelenburg positioning, and obesity, and higher still in ARDS, where the ARDS Network PEEP/FiO2 tables pair PEEP from 5 to 24 cm H2O with the inspired oxygen fraction; most patients with moderate to severe ARDS end up at 10-15 cm H2O.
Contraindications: Use caution or avoid PEEP in patients with elevated intracranial pressure, unilateral lung disease, significant hypovolemia, or an untreated pneumothorax or bronchopleural fistula, where increased intrathoracic pressure could exacerbate their conditions.
Impact on Blood Flow: PEEP can increase intrathoracic pressure, reduce venous return, and cause hypotension. Monitor hemodynamic status closely, especially in patients with cardiovascular instability.
Examples in Practice: PEEP may be gradually increased for a patient with ARDS while monitoring for improved oxygenation and lung compliance. In contrast, in a patient with unilateral pneumonia, high PEEP might worsen hypoxemia by shunting blood to the affected lung, necessitating careful titration.
Laparoscopy and Trendelenburg: Pneumoperitoneum and head-down tilt push the diaphragm cephalad, lower functional residual capacity and compliance, and promote dependent atelectasis. Raising PEEP to 8-10 cm H2O (often higher in obese patients) after a recruitment maneuver restores oxygenation and compliance; the accompanying rise in plateau pressure mostly reflects the stiffer chest wall, so judge the lung by driving pressure rather than by plateau pressure alone.
Emergence and Extubation: Recruited lung is lost at the end of the case if PEEP is removed and 100% oxygen is given before extubation. Keep PEEP on until the airway is removed, use the lowest inspired oxygen fraction that is safe, and in high-risk patients (obesity, major abdominal surgery, hypoxemia) continue the pressure after extubation: in the Squadrone trial (2005), CPAP of 7.5 cm H2O after major abdominal surgery cut reintubation from 10% to 1% compared with oxygen alone.
| Consideration | Guidance |
|---|---|
| Routine PEEP range | 3–5 cm H2O for standard use |
| Laparoscopy, Trendelenburg, obesity | 8–10 cm H2O or more, titrated to compliance; the raised plateau pressure mostly reflects the chest wall |
| PEEP in ARDS | Set from the ARDS Network PEEP/FiO2 tables (5 to 24 cm H2O; usually 10 to 15 in moderate to severe disease) |
| Use caution or avoid | Elevated intracranial pressure, unilateral lung disease, significant hypovolemia, untreated pneumothorax or bronchopleural fistula, where increased intrathoracic pressure could worsen the condition |
| Effect on blood flow | PEEP raises intrathoracic pressure, reduces venous return, and can cause hypotension; monitor hemodynamics closely with cardiovascular instability |
| ARDS in practice | Increase PEEP gradually while watching for improved oxygenation and lung compliance |
| Unilateral pneumonia in practice | High PEEP may worsen hypoxemia by shunting blood to the affected lung, so titrate carefully |
