Impact of hyperoxia on patients hospitalized in an intensive care unit for acute heart failure

Background: Oxygen therapy remains a cornerstone of treatment for acute heart failure in patients with pulmonary congestion. While avoiding hypoxaemia has long been a goal of critical care practitioners, less attention has been paid to the potential hazard related to excessive hyperoxia. Aim: To evaluate the impact of early hyperoxia exposure among critically ill patients hospitalized in an intensive care unit for acute heart failure. Methods: In this preliminary study conducted in a Parisian intensive care unit, we assessed patients with acute heart failure admitted with pulmonary congestion and treated with oxygen therapy from 1 January 2015 to 31 December 2016. The hyperoxia group was defined by having at least one partial pressure of oxygen measurement > 100 mmHg on the first day following admission to the intensive care unit. The primary endpoint was 30-day all-cause mortality. Secondary endpoints were 30-day unplanned hospital admissions, occurrence of infections and intensive care unit and hospital lengths of stay. Results: Seventy-five patients were included. Forty-three patients (57.3%) presented hyperoxia, whereas 32 patients (42.7%) did not (control group). The baseline clinical characteristics did not differ between the two groups. The primary endpoint was not statistically different between the two groups (14.0% in the hyperoxia group vs 18.8% in the control group; P = 0.85). The secondary endpoints were also not significantly different between the two groups. In the multivariable analysis, hyperoxia was not associated with increased 30-day mortality (odds ratio 0.77, 95% confidence interval 0.24–2.41). Conclusion: In patients referred to an intensive care unit for acute heart failure, we did not find any difference in outcomes according to the presence of hyperoxia.