SAN FRANCISCO, CA—Patients with ventilator-associated pneumonia (VAP) due to methicillin-resistant Staphylococcus aureus (MRSA) achieved an earlier time to clinical stability when treated with linezolid vs. vancomycin, results of the IMPACT-HAP study reported at IDWeek 2013.
“These data suggest the number of days for patients to reach clinical stability can be used as an early clinical outcome in patients with ventilator-associated pneumonia,” noted Paula Peyrani, MD, of the Division of Infectious Diseases at the University of Louisville, Louisville, KY, and colleagues on behalf of the IMPACT-HAP Study Group.
Time to clinical stability is a well-defined early clinical outcome in hospitalized patients with community-acquired pneumonia, Dr. Peyrani noted, but it has not been evaluated in patients with ventilator-associated pneumonia. In this multicenter, retrospective, observational study, the investigators compared time to clinical stability in patients with MRSA ventilator-associated pneumonia treated with linezolid vs. vancomycin.
A total of 100 nonconsecutive patients requiring intensive care were enrolled from five US academic institutions; 50 were treated with linezolid and 50 with vancomycin. Data was collected from November 2008 to October 2012. Ventilator-associated pneumonia was defined according to the Centers for Disease Control and Prevention criteria, and MRSA ventilator-associated pneumonia was defined as that isolated from a tracheal aspirate or bronchoalveolar lavage.
“A patient was considered to reach clinical stability the day the four criteria were met,” Dr. Peyrani noted; these were afebrile for 24 hours, decrease in WBC >10%, improved PaO2/FiO2 ratio of >20%, and systolic blood pressure >90mmHg.
Among patients treated with linezolid, 64% reached clinical stability compared with 70% of the vancomycin-treated patients (P=0.671). Mean number of days to reach clinical stability was 5.8 days (SD 3.0) for patients treated with linezolid vs. 7.2 days (SD 3.7) for patients treated with vancomycin (P=0.040).
Study investigators were able to conclude that earlier time to clinical stability was achieved for patients with ventilator-associated pneumonia due to methicillin-resistant Staphylococcus aureus when treated with linezolid compared to vancomycin.