Wrong antibiotic prescriptions, drug resistance driving Acinetobacter patient deaths?

Studies at hospitals around the world have found that between 30 and 70 percent of patients who acquire Acinetobacter bacterial pneumonia will die, but the reason for that wide variation in patient survival from hospital to hospital has remained elusive.

Now, a new study suggests one important cause for higher patient death rates may be hospitals’ use of the wrong antibiotics – failing to use lab tests to determine which antibiotics are effective against a given patient’s strain of Acinetobacter when prescribing antibiotic therapies.

The retrospective study of medical records for 116 patients with hospital-acquired Acinetobacter pneumonia in South Korea identified Acinetobacter multidrug resistance and pan-drug resistance (bacterial resistance to all available antibiotic drugs) as leading risk factors for patient deaths. Over 60 percent of the infections studied involved multidrug-resistant Acinetobacter, the authors reported, and 15.5 percent were pan-drug resistant strains.

While initial antibiotic therapy did not predict patient survival, inappropriate subsequent “definitive” antibiotic therapies — the use of antibiotics shown by lab tests to be ineffective against a pneumonia patient’s particular strain of Acinetobacter — was a significant risk factor for patient death.

“The results of this study showed that the inadequately treated patients had a significantly higher mortality rate than adequately treated patients, after the results of the culture samples were obtained at the time of the diagnosis of pneumonia,” the authors report. “In contrast to the inappropriate definitive antimicrobial therapy, inappropriate initial empirical therapy was not identified as an independent predictor of mortality by the multivariate analysis, even though it was a significant risk factor for mortality by the univariate analysis.”

The authors reported that they and their employers had no financial conflicts of interest related to this study.

Further reading:

Joung MK, Kwon KT, Kang CI, et al. Impact of inappropriate antimicrobial therapy on outcome in patients with hospital-acquired pneumonia caused by Acinetobacter baumannii. J. Infection. 2010 Sept.;61(3):212-218.