Rocuronium infusion requirements and plasma concentrations at constant levels of neuromuscular paralysis during three phases of liver transplantation.
STUDY OBJECTIVE: To develop a rapid online test of graft liver function during liver transplantation. DESIGN: Prospective, observational study. SETTING: University hospital transplant unit. PATIENTS: 17 adult patients with end-stage liver disease who underwent liver transplantation surgery. INTERVENTIONS: Rocuronium infusion dose requirements and plasma concentrations to maintain constant levels of neuromuscular paralysis during three phases of liver transplantation and their relationship with early postoperative liver function tests were studied. MEASUREMENTS: Infusion dose requirements of rocuronium, assay of rocuronium plasma concentrations using gas chromatography-mass spectrometry, and intensity of neuromuscular blockade were measured. MAIN RESULTS: A 24% decrease in rocuronium infusion requirements was observed during the an-hepatic phase. Rocuronium requirement during the neohepatic phase was increased only modestly or remained unchanged in 14 of the 16 patients who had normal graft function in the immediate postoperative period. Rocuronium plasma concentrations for maintaining constant levels of paralysis were significantly lower during the neohepatic phase than during the paleohepatic and anhepatic phases, indicating that there is likely to be a change in pharmacodynamics during this phase. Significant reduction in rocuronium infusion requirements during the neohepatic phase was observed in the only patient who had poor graft function in the early postoperative stage, suggesting that the reduced infusion requirement to maintain a constant neuromuscular paralysis may be related to the functional state of the graft liver after reperfusion. CONCLUSIONS: A significant reduction in rocuronium infusion requirement during the neohepatic phase may be suggestive of impaired organ function after reperfusion of the graft liver. Rocuronium may serve as a potential online indicator of graft liver function during liver transplantation by measurement of its infusion requirements during transplantation.