Isolation of Aspergillus in critically ill patients: a potential marker of poor outcome

ObjectiveRecent reports have suggested a rising incidence of pulmonary aspergillosis in intensive care unit (ICU) patients. The aim of this study was to determine the clinical significance of isolating Aspergillus from respiratory samples of critically ill patients.DesignRetrospective review of medical records.SettingTertiary medical center that has a large cancer center.PatientsAll patients admitted to the ICU between January 1998 and August 2004, in whom Aspergillus was isolated from respiratory samples or lung tissue.InterventionNone.ResultsThe charts of 104 patients were reviewed. Aspergillus was isolated for a mean of 6.6 days after ICU admission. Thirty-three percent of patients had hematological malignancy, 10% had absolute neutropenia, 14% had bone marrow transplant, 11% had HIV infection, and 22% had chronic obstructive pulmonary disease. Upon admission to ICU, 79%, 43%, and 19% were on antibiotics, corticosteroids, or immunosuppressive therapy, respectively. Ninety percent of patients required mechanical ventilation. The mean Acute Physiologic and Chronic Health Evaluation II score on ICU admission was 20.6, with predicted mortality of 35.5%. However, the actual ICU mortality rate for the cohort was 50%. Twenty-eight percent of patients were diagnosed with probable or definite invasive pulmonary aspergillosis, and 72% had Aspergillus colonization. On univariate analysis, the significant clinical differences between the 2 groups were the presence of neutropenia (P < .05), immunosuppressants (P < .05), antibiotics (P < .05), or bone marrow transplant (P < .05). The differences in Acute Physiologic and Chronic Health Evaluation II score, the need for mechanical ventilation, ICU length of stay, and ICU mortality were not statistically significant. On multivariate analysis, the following factors were independently associated with invasive diseases, bone marrow transplantation (P < .01), hematological malignancy (P = .02), and broad-spectrum antibiotics (P = .02).ConclusionIsolation of Aspergillus in critically ill patients is a poor prognostic marker and is associated with high mortality irrespective of invasion or colonization. Those who are neutropenic, on immunosuppressive therapy, on broad-spectrum antibiotics, or had bone marrow transplantation are more likely to have invasive pulmonary aspergillosis.