Moore J M, Liu S S, Neal J M
Department of Anesthesiology, Virginia Mason Medical Center and the University of Washington, Seattle 98111, USA.
Anesth Analg. 1998 May;86(5):1015-7. doi: 10.1097/00000539-199805000-00020.
This study was performed to determine whether premedication with midazolam and fentanyl prevents reliable detection of an i.v. lidocaine test dose. Thirty ASA physical status I or II patients received either 3 mL of saline or 1.5 mg of midazolam (1.5 mL) plus 75 microg of fentanyl (1.5 mL) i.v. in a randomized, double-blind fashion. Five minutes later, lidocaine 1 mg/kg was injected i.v. At 1.5 min before and every minute after lidocaine administration, each subject was questioned regarding the presence of four symptoms of systemic lidocaine toxicity. Any new tinnitus, perioral numbness, metallic taste, or light-headedness within 5 min after lidocaine administration was considered a positive response. All 15 patients in the saline group (100% sensitivity) had a positive response to i.v. lidocaine, but only 9 of 15 patients in the sedation group had a positive response (60% sensitivity; P = 0.017). We conclude that midazolam and fentanyl premedication decreases the reliability of subjective detection of i.v. lidocaine.
Anesthesiologists often rely on subjective symptoms to prevent local anesthetic toxicity while performing regional anesthesia. Sedatives are often administered during the administration of regional anesthesia. This study demonstrates that typical sedation decreases the reliability of detection of local anesthetic toxicity by subjective symptoms.
本研究旨在确定咪达唑仑和芬太尼预处理是否会妨碍对静脉注射利多卡因试验剂量的可靠检测。30例美国麻醉医师协会（ASA）身体状况I或II级的患者，以随机、双盲方式静脉注射3 mL生理盐水或1.5 mg咪达唑仑（1.5 mL）加75 μg芬太尼（1.5 mL）。5分钟后，静脉注射1 mg/kg利多卡因。在利多卡因给药前1.5分钟及给药后每分钟，询问每位受试者是否存在全身利多卡因中毒的四种症状。利多卡因给药后5分钟内出现任何新的耳鸣、口周麻木、金属味或头晕均被视为阳性反应。生理盐水组的所有15例患者（敏感性100%）对静脉注射利多卡因有阳性反应，但镇静组的15例患者中只有9例有阳性反应（敏感性60%；P = 0.017）。我们得出结论，咪达唑仑和芬太尼预处理会降低对静脉注射利多卡因主观检测的可靠性。
麻醉医生在进行区域麻醉时，常依靠主观症状来预防局部麻醉药中毒。在区域麻醉给药期间常使用镇静剂。本研究表明，典型的镇静会降低通过主观症状检测局部麻醉药中毒的可靠性。
