BACKGROUND
Suspected pneumonia is the most common indication for antibiotics in hospitalized patients but frequently overdiagnosed. We explored whether normal oxygenation could be used as an indicator to support early discontinuation of antibiotics.
METHODS
We retrospectively identified all patients started on antibiotics for pneumonia in 4 hospitals with oxygen saturations ≥95% on ambient air, May 2017-February 2021. We propensity-matched patients treated 1-2 days vs 5-8 days and compared hospital mortality and time-to-discharge using subdistribution hazard ratios (SHRs). Secondary outcomes included readmissions, 30-day mortality, C.difficile infections, hospital-free days, and antibiotic-free days.
RESULTS
Amongst 39,752 patients treated for possible pneumonia, 10,012 had median oxygen saturations ≥95% without supplemental oxygen. Of these, 2,871 were treated 1-2 days and 2,891 for 5-8 days; 4,478 patients were propensity-matched. Patients treated 1-2 vs 5-8 days had similar hospital mortality (2.1% vs 2.8%, SHR 0.75, 95% CI 0.51-1.09) but less time-to-discharge (6.1 vs 6.6 days, SHR 1.13, 95% CI 1.07-1.19) and more 30-day hospital-free days (23.1 vs 22.7, mean difference 0.44, 95% CI 0.09-0.78). There were no significant differences in 30-day readmissions (16.0% vs 15.8%, OR 1.01, 95% CI 0.86-1.19), 30-day mortality (4.6% vs 5.1%, OR 0.91, 95% CI 0.69-1.19), or 90-day C.difficile infections (1.3% vs 0.8%, OR 1.67, 95% CI 0.94-2.99).
CONCLUSIONS
One quarter of hospitalized patients treated for pneumonia had oxygenation saturations ≥95% on ambient air. Outcomes were similar with 1-2 vs 5-8 days of antibiotics. Normal oxygenation levels may help identify candidates for early antibiotic discontinuation. Prospective trials are warranted.