Standard stethoscopes were compared with an electronic stethoscope to examine breath sounds (Image source: Thinkstock)

Standard stethoscopes were compared with an electronic stethoscope to examine breath sounds (Image source: Thinkstock)

Anesthesiologists are known to wear stethoscopes around their neck. We use the stethoscope to make sure breath sounds are equal after a patient’s trachea has been intubated, to check lung physiology during anesthesia, and occasionally place the stethoscope earpiece on the ears of deaf patients and speak into the bell to amplify our own voices (if you haven’t tried it, you should). Commercially available electronic stethoscopes are more sensitive than the human ear. In one study, for example, an advanced electronic stethoscope device could detect microbruits within coronary arteries to help determine whether a patient had coronary artery disease.

In the study “Pulmonary Auscultation in the Operating Room: A Prospective Randomized Blinded Trial Comparing Electronic and Conventional Stethoscopes,” Dr. Clement Hoffmann, Department of Anesthesiology and Intensive Care Medicine, Percy Military Teaching Hospital, Clamart, France and colleagues compared use of two conventional stethoscopes (Holtex Ideal® and Littmann Cardiology III®) with an electronic stethoscope (Littmann Electronic Model 3200®). In 100 patients anesthesiologists were asked to assess breath sounds with each stethoscope. They were blinded and not allowed to touch the patient for the evaluation. A separate individual placed the stethoscope on the patient’s chest. The anesthesiologists were then asked to rate the quality of auscultation on a scale of 0 (I can hear nothing) to 10 (I can hear perfectly).

Auscultation quality was best with the Littmann Electronic Model 3200® , although the acoustic Littmann Cardiology III®) performed almost as well. The performance of the Holtex Ideal® was worse than with either of the Littmann stethoscopes. Even though sound quality was best with the electronic stethoscope, it’s not clear whether patient outcome would be improved by the better sound quality. Given these results, would more information come perioperatively from using an electronic stethoscope to assess heart and breath sounds? It’s too early to know, perhaps the acoustic stethoscope most of us use now will go the way of paper books.