Sarcopenia Is Associated with Altered Rocuronium Onset and Neuromuscular Blockade Kinetics in Liver Transplant Recipients: A Prospective Observational Cohort Study.

Background: Sarcopenia is highly prevalent in end-stage liver disease and is associated with adverse perioperative outcomes. However, its association with rocuronium pharmacodynamics during liver transplantation (LT) remains insufficiently defined. Aim: This study aimed to evaluate the association between sarcopenia, neuromuscular blockade kinetics, and clinical outcomes in LT recipients. Methods: In this prospective observational cohort study, 139 adult LT recipients were classified as sarcopenic (n = 70) or non-sarcopenic (n = 69) based on EWGSOP2 criteria, including SARC-F, handgrip strength, and psoas muscle index (PMI). Rocuronium (1 mg/kg, ideal body weight) was administered at induction, and quantitative neuromuscular monitoring was performed using train-of-four (TOF). The primary outcome was time to complete neuromuscular blockade (T0). Secondary outcomes included intraoperative neuromuscular recovery parameters, perioperative clinical variables, and postoperative outcomes. Multivariable GLM analyses were performed to evaluate factors associated with sarcopenia and T0, while logistic regression models were used to assess factors associated with mortality. Results: Sarcopenic patients exhibited significantly reduced PMI (p < 0.001) and lower handgrip strength (p = 0.001). In the baseline binomial-logit GLM, age was independently associated with sarcopenia (OR = 1.034, p = 0.025). The onset of neuromuscular blockade was significantly prolonged in the sarcopenic group (T0: 100 vs. 80 s; p < 0.001). In the adjusted Gamma regression model, sarcopenia remained significantly associated with longer T0 after adjustment for age, sex, MELD score, BMI, and hemoglobin level (adjusted ratio = 1.232, 95% CI: 1.105-1.372, p < 0.001). Postoperatively, they demonstrated prolonged extubation time (10 vs. 7 h; p < 0.001), extended ICU stay (9 vs. 6 days; p < 0.001), and higher mortality (27.1% vs. 8.7%; p = 0.009). In multivariable logistic regression, sarcopenia was independently associated with mortality (OR = 3.26; p = 0.023), while each additional ICU day was associated with an approximate 9% increase in mortality risk in the secondary model. Conclusions: Sarcopenia was associated with altered rocuronium pharmacodynamics in LT recipients, primarily characterized by delayed onset of complete neuromuscular blockade, and this association persisted after adjustment for age and other baseline clinical variables. Sarcopenic recipients also showed prolonged extubation time, longer ICU stay, and higher mortality. These findings support the integration of sarcopenia into perioperative risk stratification and individualized neuromuscular management strategies in this high-risk population.