Martin S, Jones J S, Wynn B N
Emergency Medicine Residency Program, Butterworth Hospital, Grand Rapids, MI, USA.
Am J Emerg Med. 1996 Jan;14(1):10-2. doi: 10.1016/S0735-6757(96)90003-0.
The most frequent complaint noted with the use of lidocaine (or other amide local anesthetic) is stinging or burning pain associated with subcutaneous infiltration. The purpose of this study was to evaluate the efficacy of warming buffered lidocaine for reducing the pain of infiltration. Forty adult volunteers were entered into a randomized, crossover study conducted at a community teaching hospital. Blinded subjects underwent 1-mL subcutaneous injections of the study agent through 27-gauge needles over 30 seconds. Following a crossover protocol, "room temperature" buffered lidocaine (20 degrees C) was injected into one midvolar forearm and "body temperature" buffered lidocaine (37 degrees C) into the opposite arm. The order and the handedness of the two injections were randomized; an independent observer prepared the anesthetic solutions. Pain was assessed using a 100-mm visual analog pain scale and subjects' comparison of pain on injection. Twenty subjects (50%) reported that 20 degrees C buffered lidocaine was more painful and 17 (42.5%) reported that the 37 degrees C solution was more painful (sign test, P = .74). Similarly, a median pain score difference of 5.0 mm favoring 37 degrees C lidocaine was not statistically significant (sign rank test, P = .42). The order or the initial side of the injection did not influence the pain scores. The study had a power of 80% to detect a 10-mm difference between the two solutions at alpha = .05. These results suggest that warming buffered lidocaine to body temperature (37 degrees C) does not reduce the pain of subcutaneous infiltration.
使用利多卡因（或其他酰胺类局部麻醉剂）时最常见的主诉是与皮下浸润相关的刺痛或灼痛。本研究的目的是评估温热的缓冲利多卡因减轻浸润疼痛的效果。40名成年志愿者参与了在一家社区教学医院进行的随机交叉研究。在双盲状态下，受试者通过27号针头在30秒内接受1毫升研究药物的皮下注射。按照交叉方案，将“室温”（20摄氏度）的缓冲利多卡因注射到一侧前臂掌侧中部，将“体温”（37摄氏度）的缓冲利多卡因注射到对侧手臂。两次注射的顺序和注射侧别均随机安排；由一名独立观察者配制麻醉溶液。使用100毫米视觉模拟疼痛量表评估疼痛，并让受试者比较注射时的疼痛程度。20名受试者（50%）报告20摄氏度的缓冲利多卡因更痛，17名受试者（42.5%）报告37摄氏度的溶液更痛（符号检验，P = 0.74）。同样，37摄氏度利多卡因的疼痛评分中位数比20摄氏度利多卡因高5.0毫米，但差异无统计学意义（符号秩和检验，P = 0.42）。注射顺序或初始注射侧别均不影响疼痛评分。本研究在α = 0.05时检测两种溶液之间10毫米差异的检验效能为80%。这些结果表明，将缓冲利多卡因加热至体温（37摄氏度）并不能减轻皮下浸润的疼痛。
