Abstract Rationale Severe community acquired pneumonia (CAP) is a leading cause of acute respiratory failure requiring intensive care. Inhaled nitric oxide (iNO), a selective pulmonary vasodilator, transiently enhances oxygenation in refractory hypoxemia. Although iNO has been used as a rescue therapy in adults with acute respiratory distress syndrome and COVID-19 pneumonia, its effect on clinical outcomes remains uncertain. This study aims to evaluate the impact of iNO in ICU patients with severe CAP. Methods We conducted a retrospective cohort study of adults admitted to the medical ICU with severe CAP. Patients who received iNO over a 5-year period were identified (n = 25) and compared with a control group of patients with severe CAP admitted during the most recent year (n = 30). Demographics, comorbidities, illness severity (APACHE and PSI scores), oxygenation indices (PaO2/FiO2), and clinical outcomes—including duration of mechanical ventilation, renal replacement therapy requirements, ICU and hospital length of stay, and in-hospital mortality—were compared. Continuous variables were analyzed using Welch’s t-test, and categorical variables using Chi-square or Fisher’s exact test. Results Baseline characteristics, including age (61.7 ± 15.2 vs 63.4 ± 14.8 years, p = 0.62) and BMI (28.8 ± 5.5 vs 29.3 ± 5.0 kg/m², p = 0.74), were comparable between groups. Patients who received iNO had significantly lower baseline PaO2/FiO2 ratios (118 ± 46 vs 185 ± 59, p 0.01). In this group, the mean PaO2/FiO2 ratio increased from baseline by 65 mmHg (95% CI, 42-88; p 0.001) at 24 hours, indicating a transient improvement in oxygenation without difference in the primary outcomes. There were no significant differences between groups in duration of mechanical ventilation (8.6 ± 5.2 vs 7.8 ± 4.7 days, p = 0.49), ICU length of stay (10.3 ± 6.1 vs 9.2 ± 5.5 days, p = 0.51), hospital length of stay (17.0 ± 8.7 vs 15.4 ± 8.0 days, p = 0.56), or in-hospital mortality (40% vs 33%, p = 0.68). Conclusion In this retrospective cohort of 55 patients with severe community acquired pneumonia, inhaled nitric oxide improved oxygenation but did not confer measurable benefits in survival or resource utilization. These findings support the role of iNO as a short-term rescue therapy for refractory hypoxemia rather than a mortality-modifying intervention. Larger prospective studies are needed to identify patients who may benefit from iNO and clarify its long-term impact on outcomes. This abstract is funded by: None
Camacho et al. (Fri,) studied this question.