Yang Hong-wei, Bai Nian-yue, Guo Qu-lian
Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha 410008, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2005 Feb;30(1):84-7.
To compare the anesthesia properities of hyperbaric bupivacaine with those of isobaric and hypobaric solutions when administered in the supine position undergoing hip surgery or lower limb surgery using continuous spinal anesthesia.
Sixty patients( ASA I approximately III ) scheduled for hip or lower limb surgery were randomly divided into 3 groups with 20 patients in each group: Group A: 0. 375% hyperbaric bupivacaine solutions; Group B :0.375% isobaric bupivacaine solutions; and Group C: 0. 375% hypobaric bupivacaine solutions. The following variables were measured every 2 minutes during the first 30 minutes after the intrathecal injection : the onset time of sensation block, the highest plane of analgesia, the time to reach complete motor blockade, and the plane of analgesia and the extent of lower extremities' movement (modified bromage score, BMS) at different time after the administration. Meanwhile the changes of hemodynamics were recorded.
There was no statistical difference among the basic conditions ( P > 0.05). The onset time of sensation block, and the time to reach complete motor blockade, and the time receiving the highest sharp pain sensory block in Group A were significantly shorter than those in Group B and Group C ( P < 0.01 ). The plane of analgesia obtained in the hyperbaric group was significantly higher than in both the isobaric and the hypobaric groups ( P < 0.01). The mean arterial pressure(MAP) , HR in the hyperbaric group decreased significantly after the intrathecal injection( P < 0.05 ).
The 0.375% Isobaric bupivacaine used during contiuous spinal anesthesia in the supine position produces a suitable and a more "controllable" anesthesia, but a minimum dosage of 10 approximately 12.5 mg is required to obtain adequate anesthesic conditions with moderate hemodynamic changes and satisfying analgesia effects. Under similar conditions, 0. 375% hyperbaric bupivacaine produces major hemodynamic consequences with high cephalad spread and 0. 375% hypobaric bupivacaine has a too long onset time.
比较在髋关节手术或下肢手术仰卧位时，采用连续脊麻给予高压布比卡因与等比重和低比重溶液的麻醉特性。
将60例计划行髋关节或下肢手术的患者（ASA分级I至III级）随机分为3组，每组20例：A组：0.375%高压布比卡因溶液；B组：0.375%等比重布比卡因溶液；C组：0.375%低比重布比卡因溶液。鞘内注射后前30分钟内每2分钟测量以下变量：感觉阻滞起效时间、镇痛最高平面、达到完全运动阻滞的时间，以及给药后不同时间的镇痛平面和下肢运动程度（改良 Bromage 评分，BMS）。同时记录血流动力学变化。
基础情况之间无统计学差异（P>0.05）。A组的感觉阻滞起效时间、达到完全运动阻滞的时间以及获得最高锐痛感觉阻滞的时间显著短于B组和C组（P<0.01）。高压组获得的镇痛平面显著高于等比重组和低比重组（P<0.01）。鞘内注射后高压组的平均动脉压（MAP）、心率显著下降（P<0.05）。
仰卧位连续脊麻时使用0.375%等比重布比卡因可产生合适且更“可控”的麻醉，但需要至少10至12.5mg的剂量才能获得适度血流动力学变化和满意镇痛效果的充分麻醉条件。在相似条件下，0.375%高压布比卡因会产生较大血流动力学影响且头向扩散高，而0.375%低比重布比卡因起效时间过长。
