El-Boghdadly Kariem, Chin Ki Jinn
Department of Anesthesia, Toronto Western Hospital, 399 Bathurst Street, McL 2-405, Toronto, ON, M5T 2S8, Canada.
Can J Anaesth. 2016 Mar;63(3):330-49. doi: 10.1007/s12630-015-0564-z. Epub 2016 Jan 29.
Regional anesthesia is enjoying a renaissance due in part to the advent of ultrasound guidance and the development of new techniques such as tissue plane blocks and local infiltration analgesia. The purpose of this Continuing Professional Development module is to provide practitioners with an understanding of the current state of knowledge surrounding local anesthetic systemic toxicity (LAST) in order to help them prevent and manage this complication more effectively.
The causes of LAST are multifactorial, but recognized risks include patient factors, drug doses, pharmacokinetics, and choice of regional anesthetic technique. Local anesthetic systemic toxicity produces a biphasic course of clinical events that generally begin with central nervous system excitation followed by inhibition. At the same time, it causes cardiovascular compromise due to dysrhythmias, myocardial depression, and reduced systemic vascular resistance. Clinical presentation can be highly variable, however, and atypical presentations are not uncommon. Local anesthetic systemic toxicity is prevented by careful choice and dosing of drugs, aspiration before injection, dose fractionation, use of intravascular markers and ultrasound guidance. The management of LAST includes adequate oxygenation and ventilation, seizure termination, maintenance of circulation, and intravenous lipid emulsion therapy.
Local anesthetic systemic toxicity is a potentially lethal condition with protean manifestations, and anesthesiologists must understand its risks, prevention, and safe management.
区域麻醉正迎来复兴，部分原因是超声引导技术的出现以及组织平面阻滞和局部浸润镇痛等新技术的发展。本继续职业发展模块的目的是让从业者了解局部麻醉药全身毒性（LAST）的当前知识状况，以帮助他们更有效地预防和处理这种并发症。
LAST的病因是多因素的，但公认的风险包括患者因素、药物剂量、药代动力学和区域麻醉技术的选择。局部麻醉药全身毒性会产生双相临床过程，通常始于中枢神经系统兴奋，随后是抑制。同时，它会因心律失常、心肌抑制和全身血管阻力降低而导致心血管功能受损。然而，临床表现可能高度多变，非典型表现并不罕见。通过谨慎选择药物和给药剂量、注射前回抽、分次给药、使用血管内标志物和超声引导可预防局部麻醉药全身毒性。LAST的处理包括充分给氧和通气、终止惊厥、维持循环以及静脉注射脂质乳剂治疗。
局部麻醉药全身毒性是一种具有多种表现形式的潜在致命状况，麻醉医生必须了解其风险、预防措施和安全管理方法。
