257 Are Stethoscopes and Infection Control Enemies?

Abstract

The hands and the stethoscope share the same bacteria. While frequent hand washing is the clinical norm, stethoscope hygiene is rarely performed. The placement of disposable barriers on the stethoscope diaphragm has demonstrated to provide an aseptic point of contact, but their effect on auscultation has not been evaluated. Our purpose was to determine if the placement of an aseptic barrier on the stethoscope diaphragm (DiskCover, AseptiScope Inc, San Diego, CA) interferes with its acoustic capability. Using a simulation mannequin and a digital stethoscope (Littmann® 3200, 3M™, Maplewood, MN), we evaluated health care provider’s ability to determine 15 seconds of each of 4 auscultation sounds, with and without an aseptic barrier, the presence of which they were blinded. Digital files of sounds were recorded and analyzed on Logic Pro X to generate objective data of sound amplitude. This difference was analyzed using Wilcoxon Rank Sum test. We also compared the accuracy of auscultation between standard disposable stethoscopes to that of the recording stethoscope with a barrier, which was analyzed using McNemar test. In 800 auscultations, there were no differences in auscultation accuracy by physicians, with (n=400) and without (n=400) a barrier, and no differences in the digital acoustic output tracing (see Table 1). Of 220 auscultations, auscultation mis-diagnosis occurred in 10.9% (n=12/110) of the disposable stethoscope, vs 0% (0/110) with the barrier protected recording stethoscope. Physician’s preferences were uniformly for the aseptic barrier on the recording stethoscope. Aseptic barriers are acoustically invisible and offer a superior, physician preferred, alternative to disposable stethoscopes.Table 1Auscultation accuracy with and without an aseptic barrierAuscultatory soundAccuracy with aseptic barrier N (%)Accuracy without an aseptic barrier N (%)Digital tracing amplitude difference between with and without an aseptic barrier N (%)p-valueNormal heart sounds80(20)80(20)01.00Systolic Murmur100(25)100(25)01.00DiastolicMurmur100(25)100(25)01.00Wheeze120(30)120(30)01.00 Open table in a new tab