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Aseptic Disposable Stethoscope Barrier

Acoustically Invisible and Superior to Disposable Stethoscopes
      To The Editor:
      Health care-associated infections (HAIs) occur in ∼1.7 million patients annually, and 100,000 patients die, at a cost of $147 billion.
      • Marchetti A.
      • Rossiter R.
      Economic burden of healthcare-associated infection in US acute care hospitals: societal perspective.
      Overall, 85% of stethoscopes (the physician’s third hand) are contaminated with the identical pathogens as found on the hands.
      • Longtin Y.
      Contamination of stethoscopes and physicians’ hands after a physical examination.
      Although hand hygiene is emphasized, cleaning stethoscopes between patients occurs in as few as 10% of encounters.
      • Boulée D.
      • Kalra S.
      • Haddock A.
      • Johnson T.D.
      • Peacock W.F.
      Contemporary stethoscope cleaning practices: what we haven't learned in 150 years.
      Unfortunately, Centers for Disease Control and Prevention (CDC) guidelines rely on outdated strategies, instructing providers to clean their own stethoscopes, an intervention that has repeatedly been a dismal failure. Contemporary methods to decrease stethoscope-mediated transmission of pathogens include single-use disposable aseptic diaphragm barriers placed on high-fidelity stethoscopes
      • Vasudevan R.
      • Shin J.H.
      • Chopyk J.
      • et al.
      Aseptic barriers allow a clean contact for contaminated stethoscope diaphragms.
      (Figure) or auscultation with a disposable single-use stethoscope. How these strategies affect the stethoscope’s auscultory function has not been previously described. Our purpose was to evaluate the auscultation impact of a disposable aseptic barrier and the physician’s preferences vs a disposable stethoscope.
      Figure thumbnail gr1
      FigureStethoscope barrier dispenser and stethoscope with barrier.
      We performed an institutional review board-exempt prospective evaluation assessing the sound transmission effects of an aseptic barrier (DiskCover, AseptiScope Inc, San Diego, California) placed on a stethoscope diaphragm. Using the Littmann 3200 recording stethoscope (3M, Maplewood, Minnesota) and a simulation mannequin (iSTAN, CAE, Sarasota, Florida), 28 physicians performed auscultations in prespecified locations, for 15 seconds of respiratory wheezes, normal heart sounds, systolic murmurs, and diastolic murmurs. Physicians were blinded to the barriers' presence and received sounds in random order. Digital audio files were analyzed for amplitude differences (Logic Pro X, Apple Inc., Cupertino, California), with and without the barrier. Physicians reported subjective sound-quality differences. Unblinded physicians then used Littmann stethoscopes with barriers and disposable stethoscopes (Proscope 665, ADC Inc, Hauppauge, New York) without barriers, with auscultation accuracy recorded. To compare amplitude differences among groups, the Wilcoxon rank sum test was used, and McNemar’s test was used to compare diagnostic accuracy.
      Of 800 matched observations, with and without DiskCover barriers, there were no differences in sound amplitude (P=1.0), and this was consistent for all sounds. Diagnostic accuracy of 110 auscultations using the Littman/DiskCover barrier was 100%. However, 110 disposable Proscope stethoscope auscultations had an error rate of 10.9% (12 of 110), with misinterpretation of 9 systolic murmurs as occurring during diastole and 3 diastolic murmurs identified as occurring during systole. In subjective evaluation, 95% of physicians reported a preference for their personal stethoscope with a DiskCover barrier vs the disposable Proscope stethoscope.
      Ultimately, the advantages of the DiskCover barrier are significant when it is considered that stethoscopes are dirty, and the bacteria cultured from them routinely carries significant pathogens.
      • Zachary K.C.
      • Bayne P.S.
      • Morrison V.J.
      • Ford D.S.
      • Silver L.C.
      • Hooper D.C.
      Contamination of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci.
      Our findings that the DiskCover is acoustically invisible and does not alter high-fidelity auscultation must be considered as an aseptic barrier costs only a few cents compared with several dollars for a disposable stethoscope. Our selection of a stethoscope barrier is restricted to only those with published infection-control efficacy. As no other barrier has published demonstration of performance, our acoustic results are limited to the DiskCover barrier.

      References

        • Marchetti A.
        • Rossiter R.
        Economic burden of healthcare-associated infection in US acute care hospitals: societal perspective.
        J Med Econ. 2013; 16: 1399-1404
        • Longtin Y.
        Contamination of stethoscopes and physicians’ hands after a physical examination.
        Mayo Clin Proc. 2014; 89: 291-299
        • Boulée D.
        • Kalra S.
        • Haddock A.
        • Johnson T.D.
        • Peacock W.F.
        Contemporary stethoscope cleaning practices: what we haven't learned in 150 years.
        Am J Infect Control. 2019; 7: 238-242
        • Vasudevan R.
        • Shin J.H.
        • Chopyk J.
        • et al.
        Aseptic barriers allow a clean contact for contaminated stethoscope diaphragms.
        Mayo Clin Proc Innov Qual Outcomes. 2020; 4: 21-30
        • Zachary K.C.
        • Bayne P.S.
        • Morrison V.J.
        • Ford D.S.
        • Silver L.C.
        • Hooper D.C.
        Contamination of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci.
        Infect Control Hosp Epidemiol. 2001; 22: 560-564