Cheney P R, Molzen G, Tandberg D
Division of Emergency Medicine, University of New Mexico School of Medicine, Albuquerque 87131.
Am J Emerg Med. 1991 Mar;9(2):147-8. doi: 10.1016/0735-6757(91)90177-l.
The authors propose that pH buffering of bupivicaine with sodium bicarbonate reduces the pain associated with its local subcutaneous infiltration. In a double-blind, prospective study, 62 healthy adult volunteers received a 0.5 mL subcutaneous infiltration of 0.5% buffered bupivicaine into the dorsum of a randomly chosen hand. The pH was adjusted to 7.0 by adding 0.05 mL of sodium bicarbonate (1 mEq/L [corrected]) to 10 mL vials of commercially available bupivicaine (1:200 dilution). The control hand was injected with the same amount of unbuffered agent. Pain was scored after each infiltration using a nonsegmented visual analogue scale. Student's t-test for paired measurements was used to analyze intergroup pain score differences. Forty-three subjects (69%) reported less pain with buffered bupivicaine and only 17 (27%) noted a modest increase: two subjects (3%) reported no difference. The mean pain score for the buffered agent was 22 mm compared with 30 mm for the control. The mean difference (control-experimental) was 8 mm (t = 4.64, df = 61, P less than .001). The authors conclude that the addition of sodium bicarbonate to bupivicaine reduces the pain associated with its local infiltration.
作者提出，用碳酸氢钠对布比卡因进行pH缓冲可减轻其局部皮下浸润相关的疼痛。在一项双盲前瞻性研究中，62名健康成年志愿者在随机选择的一只手的背部接受了0.5mL 0.5%缓冲布比卡因的皮下浸润。通过向10mL市售布比卡因（1:200稀释）小瓶中加入0.05mL碳酸氢钠（1mEq/L[校正后]）将pH值调至7.0。对照手注射相同量的未缓冲药物。每次浸润后使用无分段视觉模拟量表对疼痛进行评分。采用配对测量的学生t检验分析组间疼痛评分差异。43名受试者（69%）报告使用缓冲布比卡因时疼痛较轻，只有17名（27%）注意到有适度增加：2名受试者（3%）报告无差异。缓冲剂的平均疼痛评分为22mm，而对照为30mm。平均差异（对照-实验）为8mm（t=4.64，自由度=61，P<0.001）。作者得出结论，在布比卡因中添加碳酸氢钠可减轻其局部浸润相关的疼痛。
