The impact of nosocomial infections on patient outcomes following cardiac surgery.
OBJECTIVE
To evaluate the relationship between nosocomial infections and clinical outcomes following cardiac surgery, and to identify risk factors for the development of nosocomial infections in this patient population.


METHODS
Prospective cohort study.


METHODS
Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital.


METHODS
Six hundred five consecutive patients undergoing cardiac surgery.


METHODS
Prospective patient surveillance and data collection.


METHODS
Occurrence of nosocomial infections, multiorgan dysfunction, hospital mortality, and risk factors for the acquisition of nosocomial infections.


RESULTS
One hundred thirty-one (21.7%) patients acquired at least one nosocomial infection following cardiac surgery. Four independent risk factors for the development of a nosocomial infection were identified: the duration of mechanical ventilation, postoperative empiric antibiotic administration, the duration of urinary tract catheterization, and female gender. Thirty (5.0%) patients died during their hospitalization. The mortality rate of patients acquiring a nosocomial infection (11.5%) was significantly greater than the mortality rate of patients without a nosocomial infection (3.2%) (odds ratio [OR]=4.0; 95% confidence interval [CI]=2.7 to 5.8; p<0.001). Multiorgan dysfunction was found to be the most important independent determinant of hospital mortality (adjusted OR=23.8; 95% CI=13.5 to 42.1; p<0.001) along with the aortic cross-clamp time (adjusted OR=2.3; 95% CI=1.7 to 3.0; p=0.002) and severity of illness as measured by APACHE II (acute physiology and chronic health evaluation) (adjusted OR=1.1; 95% CI=1.1 to 1.2; p=0.019). Ventilator-associated pneumonia, clinical sepsis, female gender, the cardiopulmonary bypass time, and severity of illness were identified as independent risk factors for the development of multiorgan dysfunction. Among hospital survivors, patients acquiring a nosocomial infection had longer hospital lengths of stay compared to patients without a nosocomial infection (20.1+/-13.0 days vs 9.7+/-4.5 days; p<0.001).


CONCLUSIONS
Nosocomial infections, which are common following cardiac surgery, are associated with prolonged lengths of hospitalization, the development of multiorgan dysfunction, and increased hospital mortality. These data suggest potential interventions for the prevention of nosocomial infections following cardiac surgery that could substantially improve patient outcomes and decrease medical care costs.
Kollef
M H
MH
Department of Internal Medicine, Pulmonary and Critical Care, Washington University School of Medicine, St. Louis, MO 63110, USA. marin@wupulm3.wustl.edu
Sharpless
L
L
Vlasnik
J
J
Pasque
C
C
Murphy
D
D
Fraser
V J
VJ
D018806:APACHE; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D015331:Cohort Studies; D016001:Confidence Intervals; D003428:Cross Infection / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D005069:Evaluation Studies as Topic; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000209:etiology / Q000503:physiopathology; D016017:Odds Ratio; D011014:Pneumonia / Q000150:complications; D011159:Population Surveillance; D011182:Postoperative Care; D011446:Prospective Studies; D012121:Respiration, Artificial; D012307:Risk Factors; D018805:Sepsis / Q000150:complications; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D014546:Urinary Catheterization
D000900:Anti-Bacterial Agents