不同比重0.375%布比卡因用于连续蛛网膜下腔阻滞的临床研究

目的：观察相同浓度、相同剂量不同（轻、中、重）比重的布比卡因溶液用于仰卧位下肢骨科手术时连续蛛网膜下腔阻滞中的麻醉效果、血流动力学变化。方法：ASA Ⅰ～Ⅲ级择期在仰卧位行下肢骨科手术病人60例,随机分为0.375%重比重布比卡因组、0.375%等比重布比卡因组、0.375%轻比重布比卡因组,每组20例。各组均在患者平卧后经蛛网膜下腔Spinocath导管给药。首量均为2.7 ml(10 mg)。测定和记录各组患者给药后锐痛觉阻滞起效时间、最高阻滞平面、达最高阻滞平面的时间,完全运动阻滞患者例数和完全运动阻滞出现时间。记录各组给药后各时点平均动脉压（MAP）、心率（HR）、血氧饱和度（SPO2）值。结果：重比重组锐痛觉阻滞起效时间、最高锐痛觉阻滞平面出现时间、BMS 3分的出现时间均明显早于等比重组和轻比重组（P<0.01）,最高锐痛觉阻滞平面、阻滞节段数（T节段）分别与等比重组和轻比重组比较差异显著（P<0.01）;等比重组和轻比重组比较有显著性差异P<0.05）。给药后重比重组MAP,HR下降幅度与等比重组、轻比重组比较差异有显著性（P<0.05）。结论：仰卧位下肢手术时,0.375%等比重布比卡因10~12.5 mg用于连续蛛网膜下腔阻滞麻醉起效快,镇痛完善,运动神经阻滞满意,对血流动力学影响较小。

Clinical research of hyperbaric,isobaric, and hypobaric solutions of bupivacaine in continuous spinal anesthesia

OBJECTIVE: 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. METHODS: 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. RESULTS: 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 ). CONCLUSION: 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.