Bellucci R, Morselli S, Pucci V, Zordan R, Magnolfi G
Institute of Ophthalmology, University of Verona, Italy.
J Cataract Refract Surg. 1999 May;25(5):642-7.
To evaluate the intraocular penetration of lidocaine 4% topically applied before phacoemulsification.
Institute of Ophthalmology, University of Verona, and Department of Medical Pharmacology, University of Padua, Italy.
Thirty eyes having phacoemulsification for senile cataract were anesthetized by topical application of lidocaine 4%. The drug was applied 3 times in 30 minutes in 15 eyes and 6 times in 60 minutes in 15 eyes. At the beginning of surgery, aqueous humor samples were obtained to measure the lidocaine levels. Blood samples were obtained in 6 patients 30 and 60 minutes after aqueous humor collection. The aqueous humor levels were compared with the amount of pain perceived by patients during surgery.
Mean aqueous humor lidocaine concentration was 8.68 micrograms/mL +/- 2.43 (SD) after 3 instillations and 23.21 +/- 8.87 micrograms/mL after 6 instillations. Blood levels of lidocaine were negligible. Patients whose intraocular level was below 12 micrograms/mL perceived more pain during surgery. Only 2 eyes had these low levels after 6 instillations.
Topically applied lidocaine 4% effectively penetrates the eye, providing analgesia for phacoemulsification. We suggest at least 6 instillations in the hour preceding surgery. In this study, pain during surgery was primarily related to poor intraocular levels of the anesthetic agent.
评估白内障超声乳化术前局部应用4%利多卡因的眼内穿透性。
意大利维罗纳大学眼科学院和帕多瓦大学医学药理学系。
30例因老年性白内障行超声乳化术的患者，采用局部应用4%利多卡因进行麻醉。15只眼在30分钟内滴药3次，另15只眼在60分钟内滴药6次。手术开始时，采集房水样本以测定利多卡因水平。在采集房水样本后30分钟和60分钟，对6例患者采集血样。将房水水平与患者手术期间感知的疼痛程度进行比较。
3次滴注后房水利多卡因平均浓度为8.68微克/毫升±2.43（标准差），6次滴注后为23.21±8.87微克/毫升。利多卡因的血药浓度可忽略不计。眼内水平低于12微克/毫升的患者在手术期间感到更疼痛。6次滴注后只有2只眼处于这些低水平。
局部应用4%利多卡因可有效穿透眼部，为白内障超声乳化术提供镇痛作用。我们建议在手术前1小时至少滴注6次。在本研究中，手术期间的疼痛主要与眼内麻醉剂水平不足有关。
