Outcome and prognostic factors in patients with HIV-negative pneumocystis pneumonia requiring mechanical ventilation

Introduction

Pneumocystis pneumonia (PCP) in HIV-negative patients frequently presents as fulminant respiratory failure and is associated with a high mortality rate when the patient requires mechanical ventilation. The aims of this study were to evaluate the outcome and prognostic factors in the patients with HIV-negative PCP requiring mechanical ventilation (MV).

Methods

We retrospectively reviewed the medical records and collected the HIV-negative patients who were microbiologically confirmed as PCP and required MV in ICU over a 10-year period in a tertiary care teaching hospital.

Results

A total of 51 patients were identified. Mean age was 55.4 ± 15.0 years. Mean APACHE II score at ICU admission was 25.7 ± 5.8. The 28-day mortality and in-hospital mortality were 45.8% and 66.7%, respectively. Between survivors and nonsurvivors, there were no significant differences in baseline characteristics, APACHE II score, PaO₂/FiO₂ ratio, and absolute neutrophil counts on ICU admission day. Also the mortality was not different in relation to the presence of barotrauma, application of non-invasive ventilation, timing of susceptible antibiotic administration, changing or not to salvage regimens, presence of cytomegalovirus co-infection and even the microbiologic persistency in follow-up specimens. Based on the types and intensity of previous immunosuppressive therapy, we classified patients into three subgroups: patients receiving low-dose steroid maintenance ± other immunosuppressive agents (LS), which represent previously stable organ transplants; another group consisting of patients receiving recent intensive chemotherapy (CTx); and the other group refers to patients receiving high dose (defined as >2 weeks at least 1 mg/kg dose) steroid therapy ± other immunosuppressive agents (HS). Significant differences of outcome were observed among the three different groups (28-day mortality: LS = 22.2%, CTx = 29.4%, HS = 71.4%, P = 0.01; 60-day mortality: LS = 33.3%, CTx = 64.7%, HS = 81.0%, P = 0.04).

Conclusions

Our data showed that the mortality of fulminant HIV-negative PCP requiring MV was significantly different according to the types and intensity of previous immunosuppressive treatment despite similar clinical features on ICU admission.