Whittington, A.M., Whitlow, G., Hewson, D., Thomas, C., & Brett, S.J. (2009). Bacterial contamination of stethoscopes on the intensive care unit.
What is the frequency of bedside stethoscope cleaning in one intensive care unit? What is the level of bacterial contamination of the bedside and personal stethoscopes? What is the impact of current user decontamination practice on such contamination?
Quantitative point-prevalence study.
One 12-bed mixed medical and surgical intensive care unit, U.K.
Twenty-four ICU nurses and 22 health care professionals carrying stethoscopes who visited patients in the ICU (12 physicians, nine physiotherapists and one non-ICU nurse).
Main outcome measures
Culture and sensitivity results from each stethoscope's diaphragms and earpieces pre- and post-cleaning.
On two separate days, three months apart, 12 nurses per each study day at each bedside completed an anonymous questionnaire asking the frequency and method of cleaning the bedside stethoscopes. The diaphragms and earpieces of 24 ICU bedside stethoscopes (12/day) were separately swabbed pre- and post-cleaning with a sterile cotton bud, moistened with sterile saline and inoculated onto blood and MacConkey agar plates. Nurses were asked to clean their bedside stethoscopes and their choice of cleaning materials noted. Additionally, any health care professionals (physicians, physiotherapists and nurse) entering the ICU on each of the study days who were carrying a stethoscope completed the anonymous questionnaire and had their stethoscopes swabbed before and after cleaning (n=22 over study period). Inoculated plates were incubated at 37[degrees]C for 24 hours and an experienced microbiologist blinded to the identity of the plates identified and quantified any cultured organisms using standard protocols. Potential pathogens underwent antibiotic sensitivity testing.
All non-medical staff stated they cleaned the bedside or personal stethoscopes at least once/day (91% of nurses cleaned the stethoscope with each use); only three of the 12 physicians involved cleaned their stethoscopes this frequently; 25% of physicians cleaned every one to six months, while 17% had never cleaned their personal stethoscope. Use of isopropyl alcohol swabs was the preferred method of cleaning (63%), with 17% using alcohol gel and 15% using detergent wipes. Of the 24 ICU bedside stethoscopes, two diaphragms and five earpieces were colonized with both non-resistant and resistant pathogenic bacteria (e.g., acinetobacter strains, MSSA and MRSA), while personal stethoscopes were also frequently colonized with multi-drug-resistant pathogenic bacteria. Cleaning did not completely eradicate MRSA or S. maltophilia from two stethoscopes.
Nurses and allied health professionals reported cleaning stethoscopes at least daily, contrasting with medical staff, one-third of whom only cleaned their stethoscopes at best every one to six months. Both the ICU bedside stethoscopes and personal stethoscopes commonly carry potentially pathogenic bacteria. Even after cleaning, several diaphragms and earpieces were still colonized, demonstrating the importance of the development of standards of cleaning for this instrument.
Hospital-acquired infection is a major cause of morbidity and mortality in critical care units throughout the world. In addition to the severe medical consequences, there are also large economical ones (Vincent, 2003). It is well known that health care practitioners' hands serve as a major route for transmission of nosocomial infections. Indeed, hand hygiene in health care has become a patient safety initiative undertaken by the World Health Organization (WHO, 2009). The challenge for clean care, however, must extend beyond our hands to the inanimate objects that are frequently touched by our hands and the patients' bodies. This study is one such example of a local unit's attempt to address this patient safety issue.
Because of this study's small sample size, it is recognized that generalizability is limited. Although Whittington et al.'s data represent only a snapshot from one unit in one institution, this relatively small workplace audit demonstrates that there are lessons to be learned, which can be shared with others. This research article brought reflection upon my own practice and those of my professional colleagues, and I am not so sure that the results are all that different. Stethoscope cleaning is inconsistently performed, and a quick informal survey with a convenience sample of nursing friends revealed that many critical care units/institutions have no standards for stethoscope cleaning. The draping of stethoscopes around necks is still a commonly seen practice, resulting in the risk of recontamination of the diaphragm from the unclean earpieces.
It cannot be assumed that a contaminated stethoscope will lead to the colonization of patients with that organism. However, as noted by the authors of this research, the risk-benefit balance for reducing the potential risks seems indisputable and greater emphasis needs to be placed on stethoscope cleaning as part of routine practice. The report of the study design allows for easy replication and is highly encouraged, particularly if the development of a policy and/or adherence to a policy and procedure is desired and/or if a unit is searching for sources of pathogen transmission and cross-contamination.
Vincent, J. (2003). Nosocomial infections in adult intensive care units. Lancet, 361, 2068-2077.
World Health Organization. (2009). WHO Guidelines on Hand Hygiene in Health Care. Geneva, Switzerland: Author.
Judy Rashotte, RN, PhD, Director, Nursing Research & Knowledge Transfer Consultant, Children's Hospital of Eastern Ontario, Ottawa, Ontario