The use of sugammadex in obese patients

Abstract

To the Editor, We read with great interest the paper by Le Corre et al. on recurarization after reversal of rocuronium-induced neuromuscular block (NMB) with sugammadex. The authors reported a case of respiratory failure in an obese patient requiring sedation and tracheal intubation in the postoperative period. This situation occurred despite initial reversal of NMB to a train-of-four (TOF) ratio [ 0.9 with sugammadex 1.74 mg kg. We congratulate the authors for successful management of this case, and we take this opportunity to underscore an important aspect of the perioperative management of NMB in obese patients. Upper airway obstruction (UAO) in obese patients, which may be caused by the residual effects of the neuromuscular blocking agents (NMBAs), may lead to upper airway collapse and respiratory impairment in the postoperative period. To avoid these complications, a recovery to a TOF ratio C 0.9 at the adductor pollicis muscle is generally recommended. However, there is evidence that upper airway dysfunction and partial UAO may occur in some individuals even with recovery of the TOF ratio to C 0.9. The pharyngeal muscles are particularly susceptible to the residual effects of NMBAs. The impairment of the integrity of the upper airway may put obese individuals at risk for upper airway collapse and increase the risk for postoperative respiratory complications. In our view, the recovery of a TOF ratio of 0.9 should be considered insufficient, particularly in obese patients who have a pharyngeal lumen reduced in size due to peripharyngeal fatty tissue deposition and are at increased risk of UAO. We recommend to wait until a TOF ratio of 1.0 has been attained before proceeding with tracheal extubation in obese patients and to consider this value the goal for an adequate recovery from NMB in this patient population. In our experience, sugammadex now represents the best pharmacological approach to reach the threshold of 1.0 quickly and to reduce the risk of postoperative UAO and its associated morbidity. To achieve this outcome, however, it is necessary to adjust the dose of sugammadex to the level of spontaneous recovery (i.e., 2 mg kg at reappearance of T1-T2) 3,4 and base sugammadex dosing on total body weight, despite some recent evidence of efficacy of doses calculated on ideal body weight. Using the correct use of sugammadex changes the intraoperative management of NMB, but it also reduces the risk of residual paralysis or recurarization in obese patients.