Yang M K, Kim J A, Ahn H J, Choi D H
Department of Anesthesiology and Pain Medicine, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, Korea.
Br J Anaesth. 2007 Apr;98(4):515-8. doi: 10.1093/bja/aem038. Epub 2007 Mar 8.
This study examined the effect of different levels of spinal anaesthesia, induced by solutions of different baricity but containing the same amount of local anaesthetic agent, on the requirement for sedation with propofol.
Thirty-six patients undergoing varicose vein surgery under spinal anaesthesia were randomly allocated to receive tetracaine 15 mg in 3 ml of either glucose 5% (hyperbaric) or CSF (isobaric). I.V. propofol was started 5 min after the intrathecal injection and was titrated to maintain a bispectral index (BIS) score of 65-75. The propofol requirements to maintain this range in the two groups were compared every 5 min.
The propofol requirement was always lower in the hyperbaric group, with the differences becoming statistically significant 20 min after the intrathecal injection. Total consumption of propofol over the 55 min of the study was also less in the hyperbaric group.
The known difference in level of spinal anaesthetic block induced by solutions of different baricity, but the same dose of local anaesthetic, was associated with different requirements for propofol sedation as determined by BIS assessment.
本研究探讨了由不同比重但含有相同剂量局部麻醉剂的溶液诱导产生的不同水平脊髓麻醉对丙泊酚镇静需求的影响。
36例接受脊髓麻醉下静脉曲张手术的患者被随机分配，分别接受3ml含15mg丁卡因的5%葡萄糖溶液（重比重）或脑脊液（等比重）。鞘内注射后5分钟开始静脉输注丙泊酚，并进行滴定以维持脑电双频指数（BIS）评分在65 - 75。每隔5分钟比较两组维持该范围所需的丙泊酚用量。
重比重组的丙泊酚需求量始终较低，鞘内注射后20分钟差异具有统计学意义。在研究的55分钟内，重比重组丙泊酚的总消耗量也较少。
已知不同比重但相同剂量局部麻醉剂的溶液所诱导的脊髓麻醉阻滞水平存在差异，这与通过BIS评估确定的丙泊酚镇静需求不同有关。
