Inhaled Pulmonary Vasodilators — Nitric Oxide & Inhaled Prostacyclin

What these drugs do — and what they do not

Inhaled pulmonary vasodilators are delivered in the inspired gas. Preferential distribution of nitric oxide and prostacyclin to ventilated areas of the lung causes selective pulmonary vasodilation, improved ventilation/perfusion matching and decreased hypoxaemia.^[13] In severe ARDS, both inhaled prostacyclin and nitric oxide produced selective pulmonary vasodilation and a rise in PaO2, and nitric oxide reduced intrapulmonary shunt at every dose tested.^[14]

The clinical problem is the gap between physiology and outcome. In adult ARDS, inhaled nitric oxide (iNO) gives a statistically significant but transient improvement in oxygenation and does not reduce mortality; the Cochrane review found the evidence insufficient to support it in any category of critically ill patients with acute hypoxaemic respiratory failure.^[2][9] Its best-supported uses are outside adult ARDS: right-ventricular failure after major cardiac surgery, where inhaled pulmonary-selective vasodilators are described as essential therapeutics, and term or near-term infants with hypoxic respiratory failure.^[11][7]

References28ShowHide

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