Healthcare-Associated Infections in Cardiac Surgery Patients With Prolonged Intensive Care Unit Stay.

BACKGROUND: Healthcare-associated infections (HAIs) are responsible for many deaths of hospitalized patients each year. Patients with prolonged hospitalization are at high risk for HAIs. Increased efforts have been made to decrease these infections, but a recent report from the Centers for Disease Control suggests that some HAIs may be increasing. We hypothesized that HAIs would remain frequent among cardiac surgery patients with prolonged intensive care unit stay and would be associated with increased mortality.

METHODS: We performed a retrospective cohort study of adult cardiac surgery patients with prolonged intensive care unit stay (more than 7 days) over a 3-year period. Mortality differences were calculated based on whether particular HAIs occurred. Multivariable logistic regression was used to examine risk factors associated with the development of HAI. The relationship between HAI and mortality was estimated using propensity score adjusted logistic regression analysis.

RESULTS: Of 2,595 patients, 388 (15.0%) had a prolonged intensive care unit stay. Of these patients, 48.5% had at least one HAI. Unadjusted inhospital mortality for patients with HAI was 28.7%, versus 13.0% for patients without. Red blood cell transfusion was associated with increased HAI risk. After propensity score adjustment, surgical site infection and central line associated blood stream infection were associated with increased mortality. The HAIs caused by vancomycin-resistant Enterococcus sp, methicillin-resistant Stapholococcus aureus, and multidrug-resistant organisms appeared to be associated with disproportionally high mortality.

CONCLUSIONS: Healthcare-associated infections remain frequent among cardiac surgery patients with prolonged intensive care unit stay and are associated with increased mortality. Evidence-based strategies are needed to reduce these infections.