Phonocardiopulmography: the future of perioperative auscultation

Traditionally, anesthesiologists have recommended performing auscultation of breath and heart sounds with a precordial or esophageal stethoscope during anesthesia. The stethoscope is generally considered the most important single device used for monitoring. Unfortunately, many anesthesiologists neglect the perioperative use of a stethoscope, even though it provides a wealth of information about the circulatory system, heart, and lungs. Although point-of-care ultrasound appears to offer greater diagnostic value in some situations, it is premature to dismiss the stethoscope, and its diminished perioperative role should be reconsidered. Recent technological advances have allowed changes in the roles of these modalities to help attending anesthesiologists perform easy assessments using clinically meaningful information from auscultation. The phonocardiopulmogram (PCPG), a real-time visual acoustic monitor, is a rediscovered and renovated technique that allows non-invasive continuous heart-lung function monitoring. However, the novel role of the PCPG as a continuous acoustic monitor, particularly for S1 and S2 heart sounds and their respiratory variations, remains relatively unexplored. This device may convey information about cardiac contractility, cardiac output, and fluid responsiveness. Furthermore, continuous lung sound visualization has potential as a monitoring modality during anesthesia, including during bronchospasm and endobronchial intubation. With its ease of use and intuitive mechanism, the PCPG can be applied during general anesthesia and follow-up in both post-anesthesia and intensive care unit settings, particularly for the detection of acute adverse events during the perioperative period.