Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 7 3 2021 07 31 129 131 Hidekazu Ito Department of Anesthesiology, Aichi Developmental Disability Center Central Hospital, 713-8 Kagiya-cho, Kasugai-city, Aichi, Japan. Shoji Mizuno Department of Anesthesiology, Aichi Developmental Disability Center Central Hospital, 713-8 Kagiya-cho, Kasugai-city, Aichi, Japan. Kenji Iio Department of Anesthesiology, Aichi Developmental Disability Center Central Hospital, 713-8 Kagiya-cho, Kasugai-city, Aichi, Japan. 2021 02 24 2021 03 13 Background: The precordial stethoscope is a traditional and non-invasive monitoring method during pediatric general anesthesia. In this preliminary cross-sectional study, we aimed to investigate the characteristics of lung and heart sounds via precordial stethoscope and determine the optimal site for auscultation in children below 2 years of age. Methods: This study involved 68 patients who underwent general anesthesia with tracheal intubation. Auscultation sounds via precordial stethoscope were recorded in MP3 format at the following three sites: Site A-region between the clavicle and nipple on the left midclavicular line; Site B-region between the nipple and costal arch on the left midclavicular line; and Site C-point on the left midaxillary line that was horizontally leveled with Site B. Eight blinded evaluators individually and randomly scored lung and heart sounds on a 10-point scale (0: cannot hear at all and 10: can hear clearly). Results: Lung sound scores at Sites A, B, and C were 8.0 (7.0–9.0), 4.5 (2.9–6.0), and 7.0 (5.5–8.5), respectively, while heart sound scores at Sites A, B, and C were 3.5 (2.0–6.0), 6.5 (4.0–8.0), and 1.0 (0.4–2.0), respectively. Statistically significant differences were found in all pairs of sites. Conclusion: We suggest that Site A, where anesthesiologists can hear both the lung and heart sounds, is the optimal site of precordial stethoscope attachment during general anesthesia for intubated children below 2 years of age. https://aacc.tums.ac.ir/index.php/aacc/article/view/341