Sildenafil attenuates pulmonary arterial pressure but does not improve oxygenation during ARDS

Objective Pulmonary hypertension is a characteristic feature of acute respiratory distress syndrome (ARDS) and contributes to mortality. Administration of sildenafil in ambulatory patients with pulmonary hypertension improves oxygenation and ameliorates pulmonary hypertension. Our aim was to determine whether sildenafil is beneficial for patients with ARDS. Design Prospective, open-label, multicenter, interventional cohort study. Setting Medical-surgical ICU of two university hospitals. Patients Ten consecutive patients meeting the NAECC criteria for ARDS. Interventions A single dose of 50 mg sildenafil citrate administered via a nasogastric tube. Main results Administration of sildenafil in patients with ARDS decreased mean pulmonary arterial pressure from 25 to 22 mmHg ( P = 0.022) and pulmonary artery occlusion pressure from 16 to 13 mmHg ( P = 0.049). Systemic mean arterial pressures were markedly decreased from 81 to 75 mmHg ( P = 0.005). Sildenafil did not improve pulmonary arterial oxygen tension, but resulted in a further increase in the shunt fraction. Conclusion Although sildenafil reduced pulmonary arterial pressures during ARDS, the increased shunt fraction and decreased arterial oxygenation render it unsuitable for the treatment of patients with ARDS.