Negative Pressure Pulmonary Edema after Reversing Rocuronium-Induced Neuromuscular Blockade by Sugammadex

Negative pressure pulmonary edema (NPPE) is a rare complication that accompanies general anesthesia, especially after extubation. We experienced a case of negative pressure pulmonary edema after tracheal extubation following reversal of rocuronium-induced neuromuscular blockade by sugammadex. In this case, the contribution of residual muscular block on the upper airway muscle as well as large inspiratory forces created by the respiratory muscle which has a low response to muscle relaxants, is suspected as the cause. 1. Introduction Upper airway closure after tracheal extubation is a crucial event during general anesthesia. Postoperative negative pressure pulmonary edema is an uncommon but well-described complication of upper airway obstruction [1]. Most cases of NPPE develop under the presence of laryngospasm which occurs at the time of extubation due to incomplete recovery from anesthesia, secretion, or blood irritating the vocal cord [2]. Sugammadex, a modified gamma-cyclodextrin, is a novel selective agent that can reverse rocuronium-induced neuromuscular blockade [3]. It achieves reversal of muscle relaxation by complex formation with free muscle relaxant molecules. The manufacturer recommends administration of 2？mg/kg of sugammadex after the second twitch of train of four stimulation (TOF) is obtained and extubation after the presence of TOF ratio of over 0.9 [3]. We report a case of postoperative negative pressure pulmonary edema after reversal of muscle relaxation by sugammadex due to dissociated recovery from the neuromuscular agent between the upper airway smooth muscle and respiratory muscles such as the diaphragm. 2. Case Report A 41-year-old man with a weight of 70？kg and height of 163？cm underwent laparoscopic appendectomy for the diagnosis of acute appendicitis. He was generally healthy but had a history of asthma as a child. In the operating room, neuromuscular function was monitored using mechanomyography by train of four (TOF) built in the anesthesia monitor (S5 TM, GE Healthcare TM, Milwaukee, WI, USA). Calibration was performed at the right adductor pollicis. General anesthesia was induced by intravenous administration of propofol 120？mg and a bolus of remifentanil 0.05？mg followed by continuous infusion of remifentanil 0.2？μg/kg/min; rocuronium 60？mg facilitated tracheal intubation. Bilateral transversus abdominis plane (TAP) block using 0.375% ropivacaine (20？mL, each) was performed using the ultrasound technique. General anesthesia was maintained by sevoflurane 1–1.5% and continuous infusion of remifentanil 0.1-0.2？μg/kg/min, and