The Effect of Esophageal Stethoscope Insertion on the Cuff Pressure: a Prospective Observational Study

Background: High cuff pressure can induce ischemic injury to the trachea. An esophageal stethoscope can increase the cuff pressure. The purpose of this study was to evaluate the effect of an esophageal stethoscope insertion on the cuff pressure.Methods: Patients, who were scheduled for surgeries under general anesthesia, were enrolled in this prospective observational study. After induction of anesthesia, an anesthesiologist intubated a tracheal tube into the patient’s trachea and inflated the cuff manually. Then, an investigator checked the initial cuff pressure using a manometer. Next, the cuff pressure was adjusted to 24-26 mmHg. The cuff pressure was rechecked after insertion of an esophageal stethoscope. We recorded the change in cuff pressure by esophageal stethoscope.Results: One hundred twelve patients completed this study. The cuff pressure increased by an esophageal stethoscope in almost all patients and the mean cuff pressure change was 3.0 ± 3.4 cmH2O in all patients. Among all subjects, cuff pressure change over 5 cmH2O was recorded in 24 patients. When we compared the patient characteristics between patients whose cuff pressure changed over 5 cmH2O with that of other patients, females were more affected by insertion of an esophageal stethoscope, in terms of cuff pressure increase.Conclusion: Esophageal stethoscope insertion could increase cuff pressure, and females are more affected by it. Therefore, anesthesiologists should check the cuff pressure with a manometer after insertion of an esophageal stethoscope and readjust the pressure appropriately.Trial registration: ClinicalTrials.gov Identifier NCT03375554, registered on 12 December 2017 (https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0007N0H&selectaction=Edit&uid=U00026JX&ts=2&cx=-ivu5vz)