393. Incidence and Outcomes of ICU-Acquired Multi-Drug Resistant Organism Infections in the Critically Ill Geriatric Population
Session: Poster Abstract Session: Gram Negative Infection - Epidemiology and Prevention
Friday, October 21, 2011
Room: Poster Hall B1
  • IDSA poster - geri infxns.pdf (685.1 kB)
  • Background: The elderly have more interactions with health care institutions, predisposing them to colonization with multi-drug resistant organisms (MDRO), and prompting suggestions that elderly patients should receive broader-spectrum empiric antibiotics when infection is suspected.  We hypothesized that the elderly have a higher incidence of ICU-acquired MDRO infections and poorer outcomes.

    Methods: A single-institution, 14-year prospectively-collected database of all surgical ICU-acquired infections was reviewed.  Univariate analyses of demographics, incidence of MDRO infections, and mortality for patients <65 years ("adult") versus ≥65 years ("elderly") were performed using Chi-square or student's t-tests.  Multivariate analysis was used to determine the effect of being elderly on the frequency of MDRO infections and for mortality in patients with and without MDRO-infections.

    Results: Analysis identified 3413 ICU-acquired infections.  Demographics are shown (Table).  By multivariate analysis, MDRO infection is associated with immunosuppression, prior transfusions or infections, and days from admission to diagnosis, but not being elderly (OR 0.98, 95% CI 0.82-1.17, p>0.1).  Being elderly was a predictor of mortality for both MDRO (2.561, [1.80-3.65], p<0.001) and non-MDRO infections (3.71, [2.94-4.68], p<0.001), but the OR did not differ significantly between the two, suggesting that the increased mortality for all infections among the elderly is not related to MDRO. 

    Conclusion: Being elderly is associated with neither a more frequent ICU-acquired MDRO infections nor higher mortality compared to younger adults or patients with non-MDRO infections.  These data suggest that chronological age should not influence empiric antimicrobial therapy in the ICU.


    Adults (≤64)

    n = 2409

    Elderly (≥65)

    n = 1004



    13.3 ± 0.1

    11.9 ± 0.2



    653 (27.1)

    197 (19.6)


    Previous Infection

    1407 (58.4)

    607 (60.5)


    Prior Transfusion

    2077 (86.2)

    850 (84.7)


    Days, admission to treatment

    21.8 ± 0.5

    24.4 ± 1.1



    679 (28.2)

    277 (27.6)


    All Mortality

    482 / 2409 (20.0)

    400 / 1004 (39.8)


    Mortality, MDRO

    190 / 679 (28.0)

    125 / 277 (45.1)


    Mortality, no MDRO

    292 / 1730 (16.9)

    275 / 727 (37.8)


    Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

    Amani Politano, MD, MS, Tjasa Hranjec, MD, MS and Robert Sawyer, MD, Department of Surgery, University of Virginia, Charlottesville, VA


    A. Politano, None

    T. Hranjec, None

    R. Sawyer, Merck: Consultant, Consulting fee
    pfizer: Consultant, Consulting fee
    ethicon: Consultant, Consulting fee
    3M: Consultant, Consulting fee

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.