Ask the Experts - Pulmonary Vasodilators
Can we use pulmonary vasodilators (like sodium nitroprusside) in acute respiratory distress syndrome (ARDS) if there are no facilities to use nitric oxide?

Shalini Dhir, MD

There are few data regarding the efficacy of inhaled pulmonary vasodilators in ARDS (nitric oxide, PGE₁, PGI₂). In spite of numerous clinical trials, none of these therapies has shown benefit in a randomized, prospective trial, and none is recommended for use by the American Thoracic Society consensus conference. Nonspecific vasodilators like sodium nitroprusside tend to worsen oxygenation by eliminating hypoxic pulmonary vasoconstriction and vasodilating parts of the pulmonary circulation that may not be well ventilated, resulting in worsening of ventilation/perfusion matching. When used intravenously, sodium nitroprusside tends to cause excessive systemic hypotension, which may also worsen overall oxygenation. At this time, these therapies cannot be recommended, and patients with acute lung injury and ARDS should receive routine supportive care in addition to mechanical ventilation with a lung-protective strategy.