The Danger of Inferior Auscultation Tools

Background

The potential for heart failure, and thus the need for accurate auscultation, represents real risks in patients undergoing certain specific cancer treatments. As the need to prevent pathogen exposure by unclean stethoscopes cannot be addressed by simply washing the diaphragm with alcohol (leaving pathogens in as many as 28%), strategies to protect the immunocompromised patient have included single use aseptic diaphragm barriers, or single patient used disposable stethoscopes. Since the auscultation quality of these strategies are poorly described, we sought to determine their diagnostic accuracy in identifying potential cardiovascular sounds of heart failure.

Methods

Using a simulation mannequin, we performed a prospective randomized trial to determine the ability of physicians to identify sounds using the following auscultation strategies: a single patient use disposable stethoscope (Proscope 665, ADC Inc, Hauppauge, New York), a high fidelity Littman 3200 recording stethoscope (3M, Inc, St. Paul, MN), and a high fidelity Littman 3200 recording stethoscope with a DiskCover barrier (Aseptiscope, Inc, San Diego, CA) in place. Physicians, randomized to auscultation strategy, performed blinded auscultation on a simulation mannequin to identify various sounds.

Results

Overall, 28 physicians performed 910 auscultation examinations. A total of 800 were performed using the Littman 3200 stethoscope (400 with, and 400 without, the DiskCover barrier), and 110 auscultations using the single patient disposable stethoscope. Diagnostic accuracy was 100% with the Littman stethoscope, with identical accuracy with or without the DiskCover barrier in place. When using the disposable stethoscope there were 12 diagnostic errors; a 10.9% error rate. All single use stethoscope diagnostic errors were of heart murmurs (9 systolic and 3 diastolic).

Conclusions

The disposable single patient stethoscope used in this study resulted in a potential misdiagnosis number needed harm of 10 and suggests these inferior tools should not be used in patients. Using a high fidelity stethoscope with a disposable barrier was acoustically invisible, provided 100% diagnostic accuracy, and provided an aseptic patient contact.