Research and Evidence for Clinicians and Health Care Providers

Disposable Stethoscope Covers Prevent Stethoscope Contamination and Overcome Barriers to Stethoscope Hygiene

Healthcare associated infections (HAI) are a threat to patient safety and cause significant morbidity and mortality. Recognition of HAIs as a patient safety and public health concern has led to increased emphasis on comprehensive prevention and control strategies. Stethoscopes are strongly implicated as vectors facilitating the dissemination of microorganisms and viruses [1–3]. Lack of stethoscope hygiene is a widespread issue as there is no standardized stethoscope hygiene protocol and rates of systematic stethoscope sanitation remain low. Furthermore, dedicated disposable stethoscopes, often used in care of patients on contact precaution, have poorer acoustic qualities than most practitioners’ personal stethoscopes and have been identified as a potential source of nosocomial pathogens [4,5]. Resultantly, healthcare providers often breach contact precaution protocols by opting to use their personal stethoscope instead of the provided dedicated disposable stethoscope. These gaps in infection control have important implications for control of HAI and patient safety.

Several studies indicate stethoscope surfaces carry pathogenic bacteria including methicillin-resistant Staphylococcus aureus (MRSA) [6–10] and vancomycin-resistant enterococci [5,11,12]. Pathogenic organisms survive on these surfaces for over 18 hours, representing a viable temporal window for multiple transmissions [13]. Stethoscopes come into direct contact with patient’s skin, hospital surfaces, physician clothing and are used repeatedly throughout the day, most often without even intermittent sanitation. In several outbreak investigations, the organism of interest has been isolated from the stethoscope surface [14–16].

The diaphragm of the stethoscope and even tubing have been shown to harbor bacterial levels comparable to a well-known vector of infection transmission, the clinicians hands after a physical examination [10]. In a study of simulated patient examinations, stethoscope diaphragms acquired and transferred MRSA and clostridium difficile colonies at a frequency comparable to gloved hands [17]. Research suggests that from an infection control and patient satisfaction standpoint, stethoscopes should be treated as an extension of the physician’s hands.

Common methods of disinfection are not readily applicable to stethoscopes. Alcohol-based sanitizers damage the stethoscope diaphragm and tubing and have limited effectiveness against non-enveloped viruses, some enveloped viruses, gram-positive bacteria and spores, including adenovirus, H1N1, C. difficile and Cryptosporidium parvum, respectively [18–24]. C. difficile spores can be transmitted even after use of alcohol-based sanitizers, hence gloves, a physical barrier, and soap and water based washing are the most effective methods of preventing transmission of infection when caring for C. difficile infected patients [25–27]. An investigation of increases in norovirus illnesses in northern New England found that preferential use of alcohol-based sanitizers over soap and water for hand hygiene was associated with an increased risk of norovirus outbreak [21]. Furthermore, mechanical action is needed for alcohol to be effective against non-enveloped viruses (i.e., mechanical removal rather than inactivation), thus providers must use an alcohol wipe and spend approximately 15 seconds rubbing each portion of the stethoscope. Soap and water sanitization of stethoscopes is not feasible as submersion of stethoscopes in water has potential to interfere with the instrument’s functionality and is strongly discouraged by most manufacturers. Furthermore, studies report contradictory results of the effectiveness of soap and water washing of stethoscopes [3,13,28]. Disposable stethoscope covers overcome the aforementioned limitations to disinfection by precluding stethoscope contamination and pathogen transfer through utilization of a sound-permissive physical barrier that does not interfere with the instrument’s functionality.

Despite the prevalent belief among healthcare providers that stethoscopes are capable of transmitting infection, most surveys indicate 70% to 90% of physicians do not systematically disinfect their stethoscope between patient examinations [2,8,13,29–31]. A survey of nurses, nurse practitioners and physicians at a large academic pediatric hospital found seventy-six percent of respondents believe that infection transmission occurs via stethoscopes, however only 24% report disinfecting their stethoscope after every patient contact. According to the study, perceived barriers to stethoscope sanitation among nurses and physicians include concern about stethoscope wear and tear, lack of access to disinfection materials, lack of visual reminders and lack of time [31].

In the aforementioned study, healthcare providers were concerned about stethoscope wear and tear [31]. Alcohol and chlorhexidine solutions damage stethoscope diaphragms and tubing leading to accelerated stethoscope deterioration. Unlike alcohol and detergent disinfectant solutions, disposable stethoscope covers prevents contamination through a barrier between patient skin and the stethoscope diaphragm without compromise in sound quality. Thus, there is no potential for chemical or mechanical damage to the stethoscope. Healthcare providers also cited lack of visual reminders [31]. The appearance of a disposable stethoscope cover on a stethoscope is conspicuous thus disposable covers provide a clear visual reminder of stethoscope hygiene. The presence of a disposable cover on the stethoscope also visually demonstrates to patients that a guard has been put in place for their protection. Patient satisfaction may increase when disposable stethoscope covers are used as a case study recently found that the implementation of a hospital cleanliness package that included increased contact precautions, hand hygiene and communication led to gains in Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores [32].

The remaining two concerns cited included lack of time and access to disinfection materials. While alcohol-based sanitizers must be applied and mechanically spread with mild friction over each portion of the stethoscope for 15 seconds, appropriately designed covers take approximately five seconds to place on a stethoscope at a price point comparable to alcohol wipes. Much like paper covers for exam tables and disposable specula for otoscopes, disposable stethoscope covers offer a convenient, easily remembered, cost-effective mechanism to prevent pathogen transmission.

In addition to general infection control, disposable stethoscope covers can improve quality of care while reducing supply costs by replacing low-quality disposable stethoscopes used for contact precautions with providers’ high-quality stethoscopes outfitted with a full-length disposable cover.

Contact precautions are a set of standards used to prevent pathogen transmission in healthcare settings. These precautions are generally applied to patients with prior history or known colonization with a pathogenic organism. Patients on contact precaution receive dedicated noncritical medical equipment such as stethoscope, electronic thermometer and blood pressure cuff [33]. Providers caring for patients on contact precaution are required to use appropriate personal protective equipment including disposable isolation gowns and gloves [33]. The effectiveness of contact precaution measures is dependent on healthcare provider adherence to protocols [33]. It is common knowledge that healthcare providers often opt to utilize their personal high-quality stethoscope without subsequent sanitation instead of the low-quality dedicated disposable stethoscope thereby breaching standard infection control practices. Disposable stethoscopes are a fraction of the cost of regular stethoscopes and healthcare providers often note diminished ability to auscultate effectively using a disposable stethoscope. A recent study demonstrated that using disposable stethoscopes to care for patients on contact precaution could compromise identification of important auscultation findings, especially crackles and stridor.4

Dedicated disposable stethoscopes have been identified as a potential source of nosocomial pathogens. These stethoscopes are used by all providers caring for a given patient resulting in multiple opportunities for disposable stethoscope ear tips to become contaminated and spread pathogens to healthcare providers resulting in an occupational safety hazard for healthcare providers and increased risk of pathogen transmission to patients. A study demonstrated that pathogenic bacteria other than the organism prompting contact precautions could contaminate disposable stethoscope ear tips, colonize the healthcare provider’s ears and be spread to other patients during subsequent interactions [5]. Full-length disposable covers allow providers to auscultate patients in a manner compliant with contact precautions without sharing potentially contaminated dedicated equipment or incurring the costs of purchasing dedicated disposable stethoscopes.

Disposable stethoscope covers are a cost-effective and practical solution to preventing cross-contamination facilitated by stethoscopes. They address each of the perceived barriers to stethoscope sanitation and visually convey the prioritization of hygiene and infection control to patients.

References

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