Preventing Nosocomial Infection in Cardiac Surgery by Topical Oro-Nasal Decontamination

Abstract & Commentary

By David J. Pierson, MD, Professor, Pulmonary and Critical Care Medicine, Harborview Medical Center University of Washington, Seattle, WA

Dr. Pierson reports no financial relationship relevant to this field of study.

This article originally appeared in the January 2007 issue of Critical Care Alert. It was edited by David J. Pierson, MD, and nurse planner Leslie A. Hoffman, PhD, RN. It was peer reviewed by William Thompson, MD. Dr. Hoffman reports no financial relationship relevant to this field of study; she works at the Department of Acute/Tertiary Care in the School of Nursing at the University of Pittsburgh. Dr. Thompson reports no financial relationship relevant to this field of study. He is Associate Professor of Medicine at the University of Washington in Seattle.

Source: Segers P, et al. JAMA. 2006;296:2460-2466.

Synopsis: In adult patients undergoing elective cardiac surgical procedures, perioperative decontamination of the nasopharynx and oropharynx with chlorhexidine solution substantially reduced nosocomial infections and nasal carriage of S aureus, and was associated with a mean reduction in hospital stay of 0.8 days.

Segers and colleagues of the University of Amsterdam conducted this randomized, double-blind clinical trial at a 480-bed community hospital that performs 1200 cardiac surgical procedures annually. They sought to determine whether the routine application of the disinfectant chlorhexidine to the nasopharynx and oropharynx of patients undergoing cardiac surgery would decrease the incidence of nosocomial infection, nasal carriage of Staphylococcus aureus, and the duration of hospital stay.

All patients over 18 years of age who underwent sternotomy for electively-scheduled cardiac procedures and gave consent during the 25-month study period were included. They were randomized to receive 0.12% chlorhexidine gluconate both as a nasal gel and as a 10-mL mouth rinse or an apparently identical placebo. Application of the experimental solutions began on hospital admission and continued 4 times daily until the nasogastric tube was removed postoperatively, usually the day after surgery. Nosocomial infections were diagnosed using accepted criteria from the Centers for Disease Control and Prevention (CDC), and nasal surveillance cultures for S. aureus were performed at fixed intervals. All patients underwent perioperative skin cleansing and administration of intravenous cefuroxime according to institutional protocols.

In this study, 991 patients were randomly administered chlorhexidine decontamination or placebo. The overall incidence of nosocomial infection was 19.8% in the chlorhexidine group as compared to 26.2% in the placebo group (absolute risk reduction [ARR], 6.4%; 95% confidence interval [CI], 1.1%-11.7%; P = 0.002). The most severe infections—lower respiratory tract infections and deep surgical site infections—were significantly less common in the active treatment group: ARR, 6.5% and 3.2%, respectively, P = 0.002 for each. The number needed to treat in order to prevent 1 nosocomial infection was 16. In addition, S. aureus nasal carriage was reduced by 57.5% in the patients who received chlorhexidine, as compared with 18.1% in the placebo group (P < 0.001). Total hospital stay for patients treated with chlorhexidine gluconate was 9.5 days, compared with 10.3 days in the placebo group (ARR, 0.8 days; 95% CI, 0.24-1.88; P = 0.04). One patient in the active treatment group experienced temporary discoloration of the teeth; there were no other reported adverse effects.

Commentary

Nosocomial infections occur in as many as 20% of patients who undergo cardiac surgery, and are an important cause of mortality, morbidity, prolongation of hospitalization, increased antibiotic utilization, and excess costs. The source of these infections is often the patient's own organisms, the suppression of which by means of topical decontamination would seem a logical and practical strategy for reducing their incidence.

This was a study in patients undergoing elective cardiac surgery, whose ICU stays were generally short. Whether beneficial effects of routine naso- and oropharyngeal decontamination with chlorhexidine similar to those obtained in this study would be observed in medical ICU patients or in a general surgical ICU population is not known at this point.

The treatment as used in this study was both safe and inexpensive. The reported daily cost for the decontamination regimen employed was $7.20. With an average duration of decontamination of 2 days, the cost to prevent one nosocomial infection was estimated to be $230. Costs would undoubtedly be higher using the prepackaged commercial kits for oral hygiene and decontamination that are currently being marketed in the United States; an estimation of the cost to prevent one infection, assuming clinical effectiveness similar to the efficacy demonstrated by Segers et al and using actual current costs in your hospital, would be a worthwhile exercise prior to widespread adoption of this treatment.