Nosocomial Acinetobacter pneumonia: Treatment and prognostic factors in 356 cases.

BACKGROUND AND OBJECTIVE: Acinetobacter baumannii and A. baumannii/calcoaceticus complex are commonly encountered pathogens in nosocomial infections. This study aimed to evaluate the treatment and prognostic risk factors in nosocomial pneumonia caused by these microorganisms.

METHODS: The study was conducted retrospectively in Uludag University Hospital and included 356 adult non-neutropenic patients with nosocomial pneumonia.

RESULTS: Of the subjects, 94.9% (n = 338) had ventilator-associated pneumonia. The clinical response rate was 57.2%, the 14-day mortality 39.6% and the 30-day mortality 53.1%. The significant independent risk factors for the 30-day mortality were severe sepsis (OR, 2.60; 95% CI: 1.49-4.56; P = 0.001), septic shock (OR, 6.12; 95% CI: 2.75-13.64; P < 0.001), APACHE II score ≥ 20 (OR, 2.12; 95% CI: 1.28-3.50; P = 0.003) and empiric monotherapy (OR, 1.63; 95% CI: 1.00-2.64; P = 0.048). Multi-trauma (OR, 2.50; 95% CI: 1.11-5.68; P = 0.028) was found to be a protective factor. In patients with a clinical pulmonary infection score (CPIS) > 6 on the third day of treatment, both the 14- and 30-day mortality rates were high (P < 0.001, P < 0.001). Also, the 14- and 30-day mortality rates were significantly higher in the patients treated with empiric monotherapy compared with combination therapy (48/93 (51.6%)-46/123 (37.4%), P = 0.037 and 62/93 (66.7%)-65/123 (52.8%), P = 0.041, respectively) in pneumonia caused by imipenem-resistant strains.

CONCLUSION: Mortality rates were high in pneumonia caused by imipenem-resistant A. baumannii or A. baumannii/calcoaceticus complex. In the units with a high level of carbapenem resistance, antibiotic combinations should be considered for empiric therapy.