The evolution of modern medicine has led to a critical reliance on stethoscopes in the daily care of our patients. Stethoscopes, also considered to be the “third hand,” are used routinely by almost all healthcare providers across a variety of patients and hospital locations with more than 5.5 billion auscultations each year in the U.S. Despite advances in alternative diagnostics, the stethoscope remains a mainstay in bedside care, yet it is commonly utilized on serial patients while remaining unprotected.
In various observed interactions, the stethoscopes were disinfected only 18% to 55% of the time, and only a small percentage of these interactions were verified as conforming to the latest CDC guidelines. It has now been validated that this third hand carries the same burden of quality and quantity of organisms as the provider’s other two hands, even after following the current disinfection practices. These include the microbes commonly associated with healthcare-associated infections (HAIs), spores, difficult to treat organisms like multidrug resistant bacteria, viruses, and emerging resistant fungi like Candida auris.
Many of us who handle stethoscopes everyday realize that practices regarding stethoscope hygiene are subjective, remain poorly defined, are inconsistently applied, and therefore may not be very effective. Isopropyl alcohol is one of the most commonly available antiseptics in U.S. hospitals. Not only it is ineffective against infectious agents like Clostridioides difficile spores and norovirus, but it can also increase the risk of nosocomial spread of HAI-causing organisms by increasing sporulation rate of C. difficile and inducing tolerance against multidrug resistant-organisms like Enterococcus faecium and Acinetobacter baumannii. Therefore, interventions like washing the stethoscope or cleaning it with bleach or alcohol swabs may not be enough to prevent stethoscopes from becoming an effective vector in the spread of these organisms. One alternative option is a dedicated or disposable stethoscope; however, this can be associated with poor functionality and risk of misdiagnosis of up to 11-33%.
While the 2022 hand hygiene practice recommendations from the Society for Healthcare Epidemiology of America, Infectious Diseases Society of America, and Association for Professionals in Infection Control and Epidemiology (SHEA-IDSA-APIC) represent a significant advance in understanding of hand hygiene in prevention of various HAIs, the guidance is sparse for the stethoscope. The new guidelines state, “Use gloves for all contact with the patient and environment as indicated by standard and contact precautions during care of individuals with organisms confirmed to be less susceptible to biocides,” but without mention of the stethoscope. Inadequate stethoscope hygiene and associated lapses in infection prevention represent a significant risk to patients and healthcare outcomes and has the potential to negate the substantial progress in hand hygiene practices with the overall goal of reducing morbidity and mortality associated with various HAIs.
So, what are some potential solutions? Since the diaphragm is the main part of the stethoscope that comes in contact with the patient, a disposable stethoscope barrier is one potential answer. In one study, such barriers were effective in preventing the growth and nosocomial transmission of most bacteria and yeasts that might contaminate stethoscope diaphragms, while allowing practitioners to use their own stethoscope. Furthermore, this resulted in no disruption of practitioner workflow and increased perceived patient safety.
Innovations in this field of stethoscope hygiene are expected to increase as the national regulations around antimicrobial stewardship are strengthening, thus putting the fight against rising antimicrobial resistance at the intersection of clinical practice, infection control, laboratory innovation, antimicrobial stewardship, and patient satisfaction.
Prevention remains the cornerstone of current infection control practices and is now emerging as a pivotal intervention for antimicrobial stewardship programs. Each patient auscultation offers a potential opportunity for prevention of spread of nosocomial organisms where a barrier protecting the stethoscope — just like an established gown and glove barrier protection — may be a promising new addition to current best clinical practices. The under-appreciated risk mitigation offered by optimal stethoscope hygiene is the next important universal answer in our fight against antimicrobial resistance.
Abhay Dhand, MD, is an infectious diseases physician at New York Medical College/Westchester Medical Center in Valhalla, New York.