Characteristics and Outcomes of Acinetobacter baumannii Infections in Critically Ill Patients with Cancer: A Matched Case-Control Study

To describe the characteristics and outcomes of Acinetobacter baumannii (AB) infections in critically ill cancer patients and to evaluate the impact of AB on mortality and length of stay (LOS).

In a 4-year case-control study of critically ill cancer patients, we identified 161 patients with AB infections and 232 matched patients who were treated in the intensive care unit (ICU) during the same time period, but had no AB cultures. The case and control groups were matched for APACHE II, age, gender, type of malignancy, and mechanical ventilation. Most AB isolates were carbapenem-resistant (n=142, 88.2%). The majority of positive cultures were collected from the respiratory tract (58%) and blood (21.8%). The median ICU LOS and mortality rate for patients with AB infections were higher than those for the control group (12 days [IQR 6-23] vs. 3 days [IQR 1-7], p<0.0001 and 73.3% vs. 61.5%, p=0.015, respectively). AB infection was independently associated with ICU LOS and mortality: OR 1.108 (95% CI, 1.077-1.139), OR 1.658 (95% CI, 1.017-2.703), respectively.

AB infections in critically ill cancer patients were independently associated with increased mortality and increased ICU LOS. Measures to improve the outcomes of critically ill cancer patients infected with AB are necessary.