1075. Risk Factors for Ventilator-Associated Events: A Case-Control Multivariate Analysis
Session: Poster Abstract Session: Surveillance of HAIs: Evaluating National Strategy
Friday, October 4, 2013
Room: The Moscone Center: Poster Hall C
  • Abstract 41987 Risk Factors for Ventilator-Associated Events.png (266.3 kB)
  • Background:

    In 2013 the CDC released new surveillance definitions for ventilaor-associated events, including the new entities of Ventilator-Associated Conditions (VAC) and Infection-related Ventilator-Associated Complications (IVAC). Both VAC and IVAC have been shown to predict increased duration of mechanical ventilation and higher hospital mortality rates, but little is known about their risk factors.


    We conducted a case-control study to elucidate potentially modifiable risk factors for VAC and IVAC.  We matched 110 patients with VAC to 110 control patients without VAC on the basis of age, sex, ICU type, comorbidities, and duration of mechanical ventilation prior to VAC.  We then compared cases to controls with regard to demographics, comorbidities, ventilator bundle adherence, sedative choices, route of nutrition, receipt of blood products, fluid balance, and modes of ventilator support.  We repeated the analysis for the subset of VAC patients that met IVAC criteria and their associated controls.


    Patients were well matched for baseline characteristics.  On multivariate logistic regression, significant risk factors for VAC were positive fluid balances (OR 1.2 per liter positive, 95% CI 1.04 -1.41) and percent of days on mandatory modes of ventilation (OR 1.1 per 10% increase, 95% CI 1.02-1.23). Risk factors for IVAC were benzodiazepines on admission (OR 5.7, 95% CI 1.3-40) and possibly paralytic medications (OR 2.9, 95% CI 0.96-11).  Traditional VAP bundle elements, including semi-recumbent positioning, oral care with chlorhexidine, venous thromboembolism prophylaxis, stress ulcer prophylaxis, daily spontaneous breathing trial and sedative interruptions did not significantly predict VAC or IVAC.


    Mandatory modes of ventilation and positive fluid balance are risk factors for VAC. Benzodiazepines and possibly paralytic medications are risk factors for IVAC.  Prospective studies are now needed to determine if interventions directed against these targets can lower VAC and IVAC rates.

    Sarah Lewis, MD1, Lingling Li, PhD2, Michael V. Murphy, BA2 and Michael Klompas, MD, MPH, FRCPC, FIDSA2, (1)Department of Medicine, Brigham and Women's Hospital, Boston, MA, (2)Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA


    S. Lewis, None

    L. Li, None

    M. V. Murphy, None

    M. Klompas, Premier Healthcare Alliance: Independent Contractor, Speaker honorarium

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.