顺式阿曲库铵按去脂肪体质量诱导麻醉对病态肥胖患者药代动力学的影响

目的研究顺式阿曲库铵在肥胖与正常患者中药代动力学差异。方法拟12例ASAⅠ~Ⅱ级，BMI≥35 kg/m2，择期行腹腔镜胃旁路手术患者为肥胖组（Ⅰ组），12例ASAⅠ~Ⅱ级，BMI 18.5~24 kg/m2，择期行腹腔镜手术患者为正常组（Ⅱ组）。Ⅰ组按去脂肪体质量、Ⅱ组按总体质量分别给予0.15 mg/kg 顺式阿曲库铵，并于诱导前、给顺式阿曲库铵后1、2、4、6、8、10、12、15、20 min 用高效液相色谱法测定各点血药浓度，计算各项药代学参数。记录诱导前（T0）、给顺式阿曲库铵后1 min（T1）、2 min（T2）、4 min（T3）对应的SBP、DBP、HR、MAP、SpO2及PetCO2。结果与T0相比，两组组内的SBP、DBP及MAP在T1~3时明显下降（P<0.05）；与Ⅱ组对比，Ⅰ组的Hct明显升高（P<0.05）。两组术中的总体清除率、表观分布容积、分布及消除半衰期无统计学差异（P>0.05）；而与Ⅱ组相比，Ⅰ组的血药浓度在T1、T2时降低（P<0.05）。结论病态肥胖患者按去脂肪体质量予顺式阿曲库铵诱导麻醉在临床上是合理的，由于肌松起效延迟，建议气管插管时机应延后约1~2 min。

Pharmacokinetics of a cisatracurium dose according to fat-free mass for anesthesia induction in morbidly obese patients

Objective To compare the pharmacokinetics of cisatracurium between normal weight patients and morbidly obese patients. Methods Twelve obese ASA I-II patients (BMI≥35 kg/m2) undergoing laparoscopic Roux-en-Y gastric bypass and 12 normal weight ASA I-II patients (BMI of 18.5-24 kg/m2) undergoing laparoscopic surgery were enrolled. The obese patients were given a cisatracurium dose of 0.15 mg/kg according to the fat-free mass (FFM), and the non-obese patients received a dose of 0.15 mg/kg according to the total body weight. Plasma concentrations of cisatracurium was monitored in the patients with high-performance liquid chromatography (HPLC) before anesthetic induction and at 1, 2, 4, 6, 8, 10, 12, 15, and 20 min after cisatracurium administration and the pharmacokinetic parameters were computed. SBP, DBP, HR, MAP, SpO2 and PetCO2 were recorded before anesthetic induction (T0) and at 1 min (T1), 2 min (T2), 4 min (T3) after cisatracurium administration. Results Compared with those measured at T0, SBP, DBP and MAP in the 2 groups were significantly decreased at the time points of T1-3 (P<0.05). Compared with the non-obese patients, the obese patients showed significantly increased Hct level (P<0.05). The total clearance, apparent volume of distribution, and distribution and elimination half-life of the drug were similar between the 2 groups (P>0.05). The plasma concentration of cisatracurium at T1- 2 was significantly decreased in the obese patients compared with that in the non-obese patients (P<0.05). Conclusion Cisatracurium doses according to fat-free mass is clinically reasonable for inducing anesthesia in morbidly obese patients, but due to a prolonged muscle relax onset time, the timing of tracheal intubation should be delayed by 1-2 min.