Kaloul Ismail, Guay Joanne, Côté Christiane, Halwagi Antoine, Varin France
Department of Anesthesiology, Maisonneuve-Rosemont Hospital, Montréal, Québec, Canada.
Can J Anaesth. 2004 Jan;51(1):52-6. doi: 10.1007/BF03018547.
To compare ropivacaine blood concentrations obtained after a continuous lumbar plexus block performed either by the anterior three-in-one femoral (FEM) technique or the posterior (psoas compartment; PSOAS) technique.
As a substudy of a larger clinical trial, 24 patients were randomly allocated to receive a bolus of 30 mL of ropivacaine 0.5% plus epinephrine 1:200,000 followed by an infusion of ropivacaine 0.2% at 12 mL.hr(-1) for 48 hr via one of the two continuous lumbar plexus block techniques. Plasma ropivacaine concentrations, up to 48 hr, were measured by high performance liquid chromatography.
Mean plasma ropivacaine concentrations were higher in the PSOAS group at 15, 30, and 60 min (two-way analysis of variance, P < 0.0001) but areas under the curve were similar for both groups (FEM 452.4 +/- 253.6 mg.hr(-1).L(-1), PSOAS 433.4 +/- 99.0 mg.hr(-1).L(-1)). Mean maximal plasma concentrations were observed at 48 hr and were comparable for the two techniques (FEM 2630.9 +/- 1470.3 ng.L(-1), PSOAS 2325.1 +/- 604.2 ng.mL(-1)). There was no correlation between blood concentrations at 48 hr and body weight (r2 = 0.085, P = 0.21). One patient in the FEM group achieved a concentration of 6201 ng.mL(-1) at 48 hr.
Although the posterior PSOAS block results in higher early plasma concentrations of local anesthetic than the anterior three-in-one FEM block, both techniques are equivalent with regards to their potential toxicity when a continuous infusion is administered. Local anesthetic accumulation occurs with an infusion of ropivacaine 0.2% at 12 mL.hr(-1) and can lead to potentially dangerous concentrations at 48 hr.
比较采用前路三合一股神经（FEM）技术或后路（腰大肌间隙；PSOAS）技术进行连续腰丛神经阻滞术后罗哌卡因的血药浓度。
作为一项更大规模临床试验的子研究，24例患者被随机分配，通过两种连续腰丛神经阻滞技术之一，先给予30 mL 0.5%罗哌卡因加1:200,000肾上腺素的推注剂量，随后以12 mL·hr⁻¹的速度输注0.2%罗哌卡因，持续48小时。采用高效液相色谱法测量长达48小时的血浆罗哌卡因浓度。
PSOAS组在15、30和60分钟时的平均血浆罗哌卡因浓度较高（双向方差分析，P < 0.0001），但两组的曲线下面积相似（FEM组452.4 ± 253.6 mg·hr⁻¹·L⁻¹，PSOAS组433.4 ± 99.0 mg·hr⁻¹·L⁻¹）。平均最大血浆浓度在48小时时观察到，两种技术相当（FEM组2630.9 ± 1470.3 ng·L⁻¹，PSOAS组2325.1 ± 604.2 ng·mL⁻¹）。48小时时的血药浓度与体重之间无相关性（r² = 0.085，P = 0.21）。FEM组有1例患者在48小时时血药浓度达到6201 ng·mL⁻¹。
尽管后路PSOAS阻滞导致的局部麻醉药早期血浆浓度高于前路三合一FEM阻滞，但在持续输注时，两种技术在潜在毒性方面相当。以12 mL·hr⁻¹的速度输注0.2%罗哌卡因会发生局部麻醉药蓄积，并可能在48小时时导致潜在的危险浓度。
