产科麻醉意外的预防和处理

产科麻醉意外的预防和处理,复旦大学妇产科医院,区分几个概念,麻醉意外麻醉并发症责任事故,复旦大学妇产科医院,麻醉意外的影响因素,病人因素：特异体质；术前状况,麻醉因素：麻醉选择；麻醉操作；麻醉管理,仪器设备因素,麻醉医生因素,业务技术水平,工作责任心,复旦大学妇产科医院,真正的意外,过敏反应肺栓塞恶性高热,复旦大学妇产科医院,麻醉质量控制,规范科室管理人员素质教育业务学习和技术培训术前准备仪器设备,复旦大学妇产科医院,产科麻醉常见的问题,全麻困难插管肺误吸椎管内麻醉腰麻后低血压心搏骤停全脊麻硬膜外穿破后头痛（PDPH）神经并发症吗啡引起的术后呼吸抑制,复旦大学妇产科医院,全麻,尽管全麻在产科麻醉中的比例非常低，但在某些情况下是必须的美国的一项调查显示：产妇中麻醉相关的死亡率，全麻与区域阻滞相比大约在16倍以上英国的调查：产妇死亡的主要原因是插管困难和肺误吸重在术前评估和预防,Millers Anesthesia. 6th ed.,复旦大学妇产科医院,一、预防误吸,无并发症的产妇可以进饮中等量的清亮液体择期剖宫产的无并发症的产妇麻醉诱导前2h可以进饮中等量的清亮液体： water, fruit juices without pulp, carbonated beverages, clear tea, black coffee, and sports drinks摄入液体的容量大小不比是否含颗粒物质更重要,ASA Practice Guidelines for Obstetric Anesthesia. Anesthesiology, 2007, 106(4): 843,复旦大学妇产科医院,具有误吸危险因素的病人(e.g., morbid obesity, diabetes, difficult airway) 或者是具有剖宫产风险的病人(e.g., nonreassuring fetal heart rate pattern) 应基于个体病人的情况进一步限制摄入物正在分娩的产妇应禁食固体食物择期手术病人根据摄入食物类型(e.g., fat content)应禁食68h应在手术前及时使用非颗粒抗酸剂、H2受体拮抗剂和/或胃复安预防误吸,ASA Practice Guidelines for Obstetric Anesthesia. Anesthesiology, 2007, 106(4): 843,复旦大学妇产科医院,二、困难气道,The incidence of failed tracheal intubation in the pregnant population is perhaps 8 times higher than in the nonpregnant population.The first national study of anesthesia-related maternal mortality in the USA revealed that 52% of the deaths resulted from complications of general anesthesia predominantly related to airway management problems.Soft tissue changes such as airway edema are an invariable association of pregnancy, and this may contribute to difficult intubation,Kodali BS, et al. Anesthesiology 2008; 108:357,复旦大学妇产科医院,Fig. Airway pictures prelabor (Samsoon modification of Mallampaticlass 1 airway; A) and postlabor (Samsoon modificationof Mallampati class 3 airway; B).,Kodali BS, et al. Anesthesiology 2008; 108:357,复旦大学妇产科医院,ASA Practice Guidelines for Obstetric Anesthesia. Anesthesiology, 2007, 106(4): 843,复旦大学妇产科医院,椎管内麻醉,腰麻后低血压心搏骤停全脊麻硬膜外穿破后头痛（PDPH）神经并发症吗啡引起的术后呼吸抑制,复旦大学妇产科医院,一、腰麻后低血压,低血压是产妇腰麻后最常见的一种并发症其发生率远高于非妊娠妇女 低血压对产妇的影响 恶心、呕吐甚至意识丧失、心搏骤停低血压对胎儿的影响 子宫胎盘血流减少，可能引起胎儿缺氧、酸中毒甚至中枢神经系统的损伤,复旦大学妇产科医院,产妇更易发生低血压的原因,妊娠后对局麻药的敏感性增强 下腔静脉受巨大子宫的压迫引起回心血量减少 妊娠时自主神经平衡发生改变，交感神经活性相对副交感而言增强，使产妇易于发生脊麻后的低血压妊娠后外周血管对内源性和外源性血管收缩剂或血管扩张剂的反应均降低，但以1受体介导的血管收缩受到削弱的程度更显著,复旦大学妇产科医院,预防低血压的方法,减少局麻药剂量减慢注药速度麻醉前预扩容预防性使用升压药早期识别易于发生低血压的高危产妇,复旦大学妇产科医院,胶体溶液扩容,晶体液在产妇中的扩容效率约30，而胶体液可以达到100麻醉前预扩容尤其是胶体溶液扩容的优点：增加循环血量增加心输出量有效维持脊麻血流动力学的稳定预防低血压的发生尤其是显著减少严重低血压的发生率随扩容的胶体剂量增大，预防作用也越有效,复旦大学妇产科医院,扩容的优点更主要的反映在:能够降低产妇过强的交感神经张力降低子宫血管阻力增加子宫胎盘血流子宫胎盘血流的增加先于母亲动脉压的改变,Gogarten W, et al. Eur J Anaesthesiol, 2005, 22(5): 359,复旦大学妇产科医院,麻醉前预测,妊娠后自主神经平衡发生改变，交感神经活性相对副交感神经而言明显增强回顾性分析显示，脊麻时由于交感神经被阻断，发生中到重度低血压的产妇其麻醉前基础交感张力明显高于发生轻度低血压者基础交感张力更高的产妇可能脊麻后更容易发生低血压。,Hanss R, et al. Anesthesiology, 2005, 102(6): 1086,复旦大学妇产科医院,HRV,一个客观反映自主神经平衡的指标麻醉前将产妇按基础的低频高频比（LF/HF）分为两组结果：低LF/HF组（2.5）中17例产妇只有3例出现了脊麻后低血压 平均最低SBP为10514mmHg高LF/HF组（2.5）中23例产妇有20例发生了脊麻后低血压 平均最低SBP为7815mmHg,Hanss R, et al. Anesthesiology, 2006, 104(4): 635,复旦大学妇产科医院,仰卧位应激试验,麻醉前分别测量产妇左侧卧位和仰卧位的血压、心率如果产妇有易于发生主动脉、腔静脉压迫的倾向，则麻醉前在从侧卧位转成仰卧位时就会有阳性的变化,复旦大学妇产科医院,仰卧位应激试验预测脊麻后低血压的敏感度、特异度分别为69、92,Dahlgren G, et al. Int J Obstet Anesth, 2007, 16(2): 128,复旦大学妇产科医院,二、全脊麻,硬膜外穿刺操作仔细防止穿破硬脊膜硬膜外导管加药前回抽防止药物误注蛛网膜下腔给药后密切观察病人发生硬脊膜穿破并不可怕，可怕的是没有发现！一旦发生全脊麻，气管插管控制呼吸，使用大剂量血管活性药物维持循环,复旦大学妇产科医院,三、硬脊膜穿破后头痛（PDPH）,误穿破硬脊膜后PDPH的发生率高达70%, 但也并非所有的产后头痛都源于硬膜穿破其它原因包括: 非特异性头痛, 偏头痛, 颅内积气, 脑皮质小静脉血栓形成以及大脑内病理改变PDPH有体位性头痛的典型特征: 直立位加重, 平卧位缓解,复旦大学妇产科医院,预防PDPH的方法,通过硬膜外穿刺针或留置于硬膜外的导管将2030ml的胶体液注入硬膜外腔硬脊膜穿破后导管鞘内原位留置24h术后平卧三天，加强补液,Baraz1 R, et al. Anaesthesia, 2005, 60:673,复旦大学妇产科医院,PDPH的治疗,加强补液咖啡因: 缺点药效一过性、失眠非甾体抗炎药阿片类镇痛药5-羟色胺受体激动剂舒马曲坦硬膜外血填充,复旦大学妇产科医院,硬膜外血填充,The definitive treatment for PDPH In 71% of units, it was performed after the failure of conservative measures.Complications: the risk of another dural puncture, back pain and infectionBefore blood patching : check the patients temperature count white blood cell take blood for culture and sensitivity,Baraz1 R, et al. Anaesthesia, 2005, 60:673,复旦大学妇产科医院,四、神经并发症,Commonly associated factors:neurotoxic drugsantiseptic solutionstrauma to nervous tissuebacteriologic contamination epinephrinehypotensionbleedingcerebrospinal fluid leakagepatient positioning the nature of the surgical (obstetric) procedure.,Common mechanisms of injury :direct traumameningeal inflammationneural tissue compressionchronic progressive degenerative processesvascular compromiselow cerebrospinal fluid pressurepositioning with resultant peripheral nerve damage,复旦大学妇产科医院,Diagnosis of a suspected neurologic compromise,History Identify preexisting diseaseAscertain distribution of symptomsExaminationClinical neurologic assessmentEvaluation of muscle groupsLaboratory Electromyography Cerebrospinal fluid examination MRI,复旦大学妇产科医院,prevention of neurologic complications 1,Preoperative assessment: identify any preexisting neurologic condition or risk factors that could produce a neurologic lesion .Document any previously present neurologic impairment.Identify factors that are contraindications to the use of regional anesthesia.Technique:Observe meticulous sterile technique. Avoid introducing preparation solutions into the spinal or epidural space. Use preservative-free agents. Do not inject in the presence of pain or paresthesia; redirect or reinsert the needle in a different location.,复旦大学妇产科医院,prevention of neurologic complications 2,Anesthetic course:Avoid persistent hypotension. Ensure proper positioning, and avoid hyperflexion of the hips for pushing at vaginal delivery.Postoperative: Document any changes that might have occurred.Obtain neurologic consultation when appropriate.Remove epidural catheter in anticoagulated patients when the effect of the drug(s) is at a minimum and observe c