Establish The Regressive Equation Of Vecuronium Infusion Rate During Acute Hypervolemic Hemodilution

Objective: To investigate the effect of acute hypervolemic hemodilution (AHHD) on the pharmacodynamics of vecuronium by continuous infusion and derive the regressive equation of vecuronium infusion rate during AHHD. Methods: Thirty two patients, ASA â…  â…¡, scheduled for otolaryngologic surgery, were divided into two groups randomly( AHHD group and control group). The patients were monitored by TOF-Watch(?)SX in the both groups. In the AHHD group, AHHD was performed after general anesthesia. Ten minutes after AHHD, 0.1 mg·kg^-1 loading dose of vecuronium was given. The return of T₁ was awaited and the patients then received a 4 mg test dose of vecuronium. After the subsequent return of T₁, the time was noted and an infusion of vecuronium commenced. Arterial blood samples were taken for determination of Hct, Hb, liver and kidney function, electrolytes, concentrations of TPP and Alb before and after AHHD, and at the end of the surgery. Furthermore, we should observe effect indices of muscle relaxant and clinical signs for recovery after operation.Results: Compared with those before AHHD, Hb and Hct dropped by 34.5% and 32.6%, TPP and Alb dropped by 21.9% and 25.9%, concentrations of K⁺ and Ca²⁺ dropped by 7.7% and 47.8% respectively after AHHD. The difference of these indices was statistically significant. Recovery index was (15.6±8.3) min in the AHHD group and (21.8±8.6) min in the control group. The difference was significant. According to the correlation between the duration of action of test dose and infusion rate, we can...