Acute Respiratory Failure Due to Pneumocystis Pneumonia in Patients Without Human Immunodeficiency Virus Infection: Outcome and Associated Features

Objective: To examine outcome and associated factors of acute respiratory failure (ARF) in non-HIV-related Pneumocystis pneumonia (PCP) in patients admitted to a medical ICU between 1995 and 2002.

Design: A retrospective review of medical records and an APACHE (acute physiology and chronic health evaluation) III database.

Setting: Academic tertiary medical center.

Results: We identified 30 patients with non-HIV-related PCP and ARF. In-hospital, 6-month, and 1-year mortality rates were 67%, 77%, and 80%, respectively. Median age was 63.5 years. Median APACHE III score on day 1 was 65.5. Median ICU and hospital lengths of stay were 13 days and 21 days, respectively. All seven patients having a pneumothorax died. All but one patient had an elevated lactate dehydrogenase level (median, 563 U/L). The diagnosis was made using BAL in 28 patients and by transbronchial biopsy in the remaining 2 patients. All patients were immunosuppressed (eight were receiving corticosteroids, seven were receiving chemotherapy, and the remainder received both). Median immunosuppressive prednisone-equivalent dose was 40 mg (median length of treatment, 4.5 months). Not a single patient received PCP prophylaxis. All but one patient required intubation and invasive positive pressure ventilation (PPV). Hospital mortality was associated with high APACHE III scores on day 1 (p = 0.05), intubation delay (p = 0.03), length of PPV (p = 0.003), and development of pneumothorax (p = 0.033). Logistic regression analysis demonstrated that association of intubation delay with hospital mortality persisted after adjusting for severity of illness (p = 0.03).

Conclusions: Among patients with ARF secondary to non-HIV-related PCP, poor prognostic factors include high APACHE III scores, intubation delay, longer duration of PPV, and development of pneumothorax. None of the patients in this series received PCP prophylaxis prior to the development of pneumonia.