Impact of inhaled nitric oxide on clinical outcomes in severe acute respiratory distress syndrome with associated right ventricular dysfunction.

A significant number of patients with acute respiratory distress syndrome (ARDS) develop right ventricular (RV) dysfunction, which is an independent poor prognostic marker in ARDS; currently there are no well-established treatment approaches directed at this ARDS subphenotype. This study aimed to determine whether inhaled nitric oxide (iNO), when used for refractory hypoxemia, was associated with differences in clinical outcomes among patients with ARDS-associated RV dysfunction as compared to patients with normal RV function. This was a retrospective single-center cohort analysis of 52 patients with ARDS with normal and dysfunctional RVs who were treated with iNO. The outcomes of interest were death during hospitalization, 28-day mortality, and initiation of renal replacement therapy. There was no significant mortality difference during hospitalization or 28 days between the RV dysfunction and normal RV group while hospitalized or 28-days post-admission. In a Cox proportional hazards model adjusting for length of iNO treatment, each additional hour of iNO showed a small yet significant mortality benefit of 2.5 % (HR = 0.975, 95 % CI: 0.957-0.993, p < 0.01) across both groups. There was no significant difference in need for renal replacement therapy, length of hospitalization or ICU stay, or vasopressor requirements between the groups. Although ARDS-associated RV dysfunction is frequently associated with poorer outcomes as compared to patients with ARDS and normal RV, the use of iNO may even the gap in mortality. Longer duration of treatment with iNO may improve survival. These data justify further investigation into the use of iNO for this subphenotype of ARDS.