Swimming-Induced Pulmonary Edema: Pathophysiology and Risk Reduction With Sildenafil.

Area of Science:

• Cardiovascular Physiology
• Pulmonary Medicine
• Exercise Physiology

Background:

• Swimming-induced pulmonary edema (SIPE) is a poorly understood condition affecting swimmers and divers.
• Pathophysiology is unclear, often occurring in young, healthy individuals.

Purpose of the Study:

• To test if SIPE-susceptible individuals have higher pulmonary artery and wedge pressures during submerged exercise.
• To determine if sildenafil can reduce these elevated pressures.

Main Methods:

• Instrumented 10 SIPE-susceptible subjects and 20 controls with arterial and pulmonary artery catheters.
• Subjects performed moderate cycle ergometer exercise submerged in 20°C water.
• SIPE-susceptible subjects repeated exercise after 50 mg oral sildenafil.

Main Results:

• SIPE-susceptible individuals exhibited significantly higher mean pulmonary artery pressure (34.0 vs 22.5 mm Hg) and pulmonary artery wedge pressure (18.8 vs 11.0 mm Hg) during exercise compared to controls.
• Cardiac output was lower in SIPE-susceptible subjects (13.8 vs 17.9 L·min⁻¹).
• Sildenafil administration normalized pulmonary artery pressures in SIPE-susceptible subjects without adverse hemodynamic effects.

Conclusions:

• SIPE is confirmed as a form of hemodynamic pulmonary edema.
• Sildenafil's ability to reduce pulmonary vascular pressures suggests its potential utility in preventing SIPE.