Association of time-to-treatment with outcomes of Pneumocystis pneumonia with respiratory failure in HIV-negative patients

The prevalence of pneumocystis pneumonia (PCP) and associated hypoxic respiratory failure is increasing in human immunodeficiency virus (HIV)-negative patients. However, no prior studies have evaluated the effect of early anti-PCP treatment on clinical outcomes in HIV-negative patient with severe PCP. Therefore, this study investigated the association between the time to anti-PCP treatment and the clinical outcomes in HIV-negative patients with PCP who presented with hypoxemic respiratory failure. A retrospective observational study was performed involving 51 HIV-negative patients with PCP who presented in respiratory failure and were admitted to the intensive care unit between October 2005 and July 2018. A logistic regression model was used to adjust for potential confounding factors in the association between the time to anti-PCP treatment and in-hospital mortality. All patients were treated with appropriate anti-PCP treatment, primarily involving trimethoprim/sulfamethoxazole. The median time to anti-PCP treatment was 58.0 (28.0-97.8) hours. Thirty-one (60.8%) patients were treated empirically prior to confirmation of the microbiological diagnosis. However, the hospital mortality rates were not associated with increasing quartiles of time until anti-PCP treatment (P = 0.818, test for trend). In addition, hospital mortality of patients received early empiric treatment was not better than those of patients received definitive treatment after microbiologic diagnosis (48.4% vs. 40.0%, P = 0.765). In a multiple logistic regression model, the time to anti-PCP treatment was not associated with increased mortality. However, age (adjusted OR 1.07, 95% CI 1.01-1.14) and failure to initial treatment (adjusted OR 13.03, 95% CI 2.34-72.65) were independently associated with increased mortality. There was no association between the time to anti-PCP treatment and treatment outcomes in HIV-negative patients with PCP who presented in hypoxemic respiratory failure.