Neuromuscular block in obese patients

Abstract

Neuromuscular blockers (NMBs) have an important role in anesthesia, especially in obese patients, to facilitate intubation and improve surgical conditions. However, there have been discrepancies in dosing due to physiological and pharmacokinetic alterations associated with obesity. The concept of normalized lean weight (NWW) is presented as an option to avoid overdosing and provide adequate latency and duration. The review focuses on the evidence on weight scales for BNM dosing. Pharmacokinetic alterations in the obese, such as changes in drug distribution and metabolism, and how this affects the dosing of non-depolarizing BNMs such as rocuronium, vecuronium and atracurium, as well as succinylcholine, are discussed. Studies comparing different weight scales and the efficacy of quantitative monitoring of neuromuscular blockade are highlighted. In addition, the importance of complete reversal of neuromuscular blockade at the end of surgery, especially in obese patients, is emphasized. Sugammadex is presented as the drug of choice to reverse residual blockade.