In intraoperative pulmonary edema due to LV failure, what is the role of PEEP?

• A. It should be avoided
• B. It helps improve oxygenation and reduces work of breathing
• C. It worsens edema
• D. It has no effect

Answer: (B)

PEEP helps in this situation by keeping the airways open at the end of expiration, which recruits more alveoli, increases the functional residual capacity, and reduces the intrapulmonary shunt. This improves oxygenation and makes breathing less work-intensive for the patient. In cardiogenic pulmonary edema from LV failure, improved alveolar recruitment translates into better gas exchange, so oxygenation improves. The slight rise in intrathoracic pressure from PEEP can also reduce venous return and LV preload, which can help lower pulmonary capillary pressures and edema, though too much PEEP can decrease cardiac output. In the intraoperative setting, a moderate amount of PEEP is typically used to enhance oxygenation and reduce the work of breathing while closely monitoring hemodynamics.