Inhaled Nitric Oxide vs Epoprostenol During Acute Respiratory Failure: An Observational Target Trial Emulation

The inhaled vasodilators nitric oxide and epoprostenol may be initiated to improve oxygenation in mechanically ventilated patients with severe acute respiratory failure (ARF); however, practice patterns and head-to-head comparisons of effectiveness are unclear.

What are the practice patterns and comparative effectiveness for inhaled nitric oxide and epoprostenol in severe ARF?

Using a large US database (Premier Healthcare Database), we identified adult patients with ARF or ARDS who were mechanically ventilated and started on inhaled nitric oxide, epoprostenol, or both. Leveraging large hospital variation in the choice of initial inhaled vasodilator, we compared the effectiveness of inhaled nitric oxide with that of epoprostenol by limiting analysis to patients admitted to hospitals that exclusively used either inhaled nitric oxide or epoprostenol. The primary outcome of successful extubation was modeled using multivariate Fine-Grey competing risk (death or hospice discharge) time-to-event models.

Among 11,200 patients (303 hospitals), 6,366 patients (56.8%) received inhaled nitric oxide first, 4,720 patients (42.1%) received inhaled epoprostenol first, and 114 patients (1.0%) received both therapies on the same day. One hundred four hospitals (34.3%; 1,666 patients) exclusively used nitric oxide and 118 hospitals (38.9%; 1,812 patients) exclusively used epoprostenol. No differences were found in the likelihood of successful extubation between patients admitted to nitric oxide-only hospitals vs those admitted to epoprostenol-only hospitals (subdistribution hazard ratio, 0.97; 95% CI, 0.80-1.18). Also no differences were found in total hospital costs or death. Results were robust to multiple sensitivity analyses.

Large variation exists in the use of initial inhaled vasodilator for respiratory failure across US hospitals. Comparative effectiveness analyses identified no differences in outcomes based on inhaled vasodilator type.