单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,产科麻醉意外的预防和处理,区分几个概念,麻醉意外,麻醉并发症,责任事故,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,真正的意外,过敏反响,肺栓塞,恶性高热,麻醉质量控制,标准科室管理,人员素质教育,业务学习和技术培训,术前准备,仪器设备,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,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.,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,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):843,二、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 2021;108:357,ASA Practice Guidelines for Obstetric Anesthesia.,Anesthesiology,2007,106(4):843,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,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,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响均降低，但以1受体介导的血管收缩受到削弱的程度更显著,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,胶体溶液扩容,晶体液在产妇中的扩容效率约30，而胶体液可以到达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,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,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,回忆性分析显示，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根底交感张力明显高于发生轻度低血压者,根底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,HRV,一个客观反映自主神经平衡的指标,麻醉前将产妇按根底的低频高频比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,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，那么麻醉前在从侧卧位转成仰卧位时就会有阳性的变化,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):128,二、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,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,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,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-羟色胺受体冲动剂舒马曲坦,硬膜外血填充,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 infection,Before blood patching,:,check the patients temperature,count white blood cell,take blood for culture and sensitivity,Baraz1 R,et al.,Anaesthesia,2005,60:,673,四、神经并发症,Commonly associated factors:,neurotoxic drugs,antiseptic solutions,trauma to nervous tissue,bacteriologic contamination,epinephrine,hypotension,bleeding,cerebrospinal fluid leakage,patient positioning,the nature of the surgical(obstetric)procedure.,Common mechanisms of injury:,direct trauma,meningeal inflammation,neural tissue compression,chronic progressive degenerative processes,vascular compromise,low cerebrospinal fluid pressure,positioning with resultant peripheral nerve damage,Diagnosis of a suspected neurologic compromise,History,Identify preexisting disease,Ascertain distribution of symptoms,Examination,Clinical neurologic assessment,Evaluation of muscle groups,Laboratory,Electromyography,Cerebrospinal fluid examination,MRI,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.,prevention of neurologic complications 2,Anesthetic course:,Avoid persistent hypotension.,Ensure proper positioning,and avoid hyperflexion of the hips for pushing at vagin