The value of acoustic respiratory rate monitoring in a patient with postoperative hemorrhage after thyroidectomy: a case report.

Acoustic respiratory rate (RRa) monitoring is a non-invasive method of monitoring respiratory rate in spontaneously breathing individuals. The aim of this report is to highlight the clinical utility of this monitoring system in post-thyroidectomy patients by presenting a case of respiratory compromise due to post-thyroidectomy hematoma, in which the alarm of the respiratory rate monitor alerted the nursing staff about the complication. A 61-year-old woman who uneventfully underwent right thyroid lobectomy for adenomatous goiter under general anesthesia with endotracheal intubation was being monitored postoperatively using the RRa monitoring system. The alarm of the monitor suddenly indicated tachypnea, with an increase in respiratory rate from 8 to 30 breaths/min over less than 3 min, although with normal oxygenation (SaO2 99%). Physical examination revealed the presence of a hematoma due to postoperative bleeding, which was emergently treated surgically under general anesthesia with awake videolaryngoscopy-assisted endotracheal intubation, with adequate preparations for emergency tracheostomy, if required. Videolaryngoscopy before the intubation revealed mild laryngopharyngeal edema and tracheal displacement, although awake endotracheal intubation could be easily performed with a metallic tube. Thereafter, after anesthesia induction, the hematoma was drained, hemostasis was achieved, and the wound was closed after surgical drain insertion. The patient was extubated postoperatively without any further respiratory events. The information on respiratory rate disorders provided by RRa monitoring, including the tachypnea alarm, can contribute to early detection of postoperative respiratory complications and to avoiding life-threatening situations following certain operations, such as thyroidectomy.