老年病人手术的麻醉.ppt

,老年病人手术的麻醉 GERIATRIC ANESTHESIA,哈尔滨医科大学第二临床医学院 麻醉学教研室,张瑞芹,GERIATRIC ANESTHESIA,Department of Anesthesiology， the Second Affiliated Hospital， Harbin Medical University,Zhang Ruiqin,主 要 内 容,前 言,社会老龄化,2000年全国第五次人口普查，我国65岁 人口为8811万，占总人口6.96%,50%老龄人经历一次手术,2004年上海市资料，60岁以上占人口总数19.28% 20102020年， 60岁以上将达到32%,上海市资料,美国讯 ， 65岁以上占人口12%，每年二千五百万例次手术中，占1/3，约占总医疗费的1/2，达700亿美元 19992001，仁济手术总数18646例，老年65岁4820例，占25.8%,INTRODUCTION,3-fold increased risk for perioperative death compared with younger patients increased risk of perioperative mortality and morbidity include thoracic, intraperitoneal and major vascular procedures physiology, anatomy , pharmacological agents,INTRODUCTION,high frequency of serious physiological abnormalities in elderly patients demands a particularly careful preoperative evaluation,生理特点,生理特点,WHO划分年龄标准,中年 49-59岁,较老年 60-74岁,老年 7589岁,长寿老年 90岁以上,AGE-RELATED ANATOMIC & PHYSIOLOGICAL CHANGES,CARDIOVASCULAR SYSTEM RESPIRATORY SYSTEM METABOLIC & ENDOCRINE FUNCTION RENAL FUNCTION GASTROINTESTINAL FUNCTION NERVOUS SYSTEM MUSCULOSKELETAL,心血管和植物神经系统（一）,心肌纤维化致弹性减退 心肌肥厚、 心室舒张和充盈减少、CO、SV、 射血分数减少 氧输送（DO2）等均减少,动脉硬化，SVR升高，血压升高 静脉弹性减退，顺应性下降，容量相对不足 动脉硬化尤其是主动脉弓，压力感受器调节血压、心率功能减退,心血管和植物神经系统（二）,窦房结功能减退 副交感神经系统张力、受体反应下降 左房、肺血管充盈增加，引起肺充血 心室舒张功能减退,CARDIOVASCULAR SYSTEM 1,atherosclerosis reduction in arterial elasticity Reduced arterial compliance Baroreceptor function is depressed Increased vagal tone and decreased sensitivity of adrenergic receptors lead to a decline in heart rate,CARDIOVASCULAR SYSTEM 2,loss of sinoatrial node cells increase the incidence of dysrhythmias, particularly atrial fibrillation and flutter,CARDIOVASCULAR SYSTEM 3,Doppler echocardiography diastolic dysfunction may be seen with systemic hypertension, coronary artery disease, cardiomyopathies, and valvular heart disease, particularly aortic stenosis,CARDIOVASCULAR SYSTEM 4,Diastolic dysfunction results in increases in ventricular end-diastolic pressure with small changes of left ventricular volume Atrial enlargement atrial fibrillation and flutter developing congestive heart failure,CARDIOVASCULAR SYSTEM 5,Diminished cardiac reserve induction of general anesthesia A prolonged circulation time delays the onset of intravenous drugs but speeds induction with inhalational agents elderly patients have less ability to respond to hypovolemia, hypotension, or hypoxia with an increase in heart rate,呼吸系统（一）,肋骨、胸骨、肋软骨变性,胸廓弹性减少 呼吸肌减弱 肺泡气体交换面积减少,解剖和生理死腔增加，肺实质弹性组织 减少，肺顺应性下降,FEV1下降,肺活量（VC）减小，残余气量增加,呼吸系统（二）,肺泡弹性回缩 ，通气/灌流，肺血 流 ，PaO2,缺氧性肺血管收缩（HPV）反射对高碳酸血症和低氧血症的通气反应减弱,75岁时下降至735mmHg,RESPIRATORY SYSTEM 1,Elasticity is decreased in lung tissue Both anatomic and physiological dead space increase Mask ventilation may be more difficult in edentulous patients, whereas arthritis of the temporomandibular joint or cervical spine may make intubation challenging. On the other hand, the absence of upper teeth often improves visualization of the vocal cords during laryngoscopy,RESPIRATORY SYSTEM 2,Prevention of perioperative hypoxia,a higher inspired oxygen concentrations during anesthesia Aspiration pneumonia is a common and potentially life-threatening complication in elderly patients pain control techniques that facilitate postoperative pulmonary function should be seriously considered,神经系统（一）,脑平均重量 、神经原减少,15%50%,神经原缩小，密度减少,30%,脑血流减少,10%20%,脑灌流减少，脑氧代谢下降,神经递质、受体减少,精神神经系统功能减退,神经系统（二）,自主神经兴奋性下降 对循环系统调节减弱 保护性喉反射迟钝 对麻醉和手术应激的适应能力下降,对麻醉药敏感性升高 不易维持血流动力学稳定 体位改变易引起收缩压明显下降,NERVOUS SYSTEM 1,Brain mass decreases with age increasing threshold for nearly all sensory modalities, including touch, temperature sensation, proprioception, hearing, and vision anesthetics are reduced. and general Dosage requirements for local,NERVOUS SYSTEM 2,Administration of a given volume of epidural anesthetic tends to result in more extensive cephalad spread in elderly patients Elderly patients often take more time to recover completely from the central nervous system effects of general anesthesia,NERVOUS SYSTEM 3,The etiology of postoperative cognitive dysfunction (POCD) is likely multifactorial and includes drug effects, pain, underlying dementia, hypothermia, and metabolic disturbances Low levels of certain neurotransmitters, such as acetylcholine, may be contributory. Elderly patients are particularly sensitive to centrally acting anticholinergic agents such as scopolamine and atropine,NERVOUS SYSTEM 4,Some patients suffer from prolonged or permanent POCD after surgery and anesthesia Some studies suggest that POCD can be detected in 1015% of patients 60 years of age up to 3 months following major surgery,NERVOUS SYSTEM 5,Elderly inpatients appear to have a significantly higher risk for POCD than elderly outpatients Although the etiology remains unclear, both anesthetic and nonanesthetic factors are likely responsible for POCD,老年人身体成分改变,肌肉减少,脂肪增多,体内含水量减少,女性改变比男性大,骨质疏松，易骨折 骨质增生，易钙化 脊柱畸形或关节僵直挛缩 椎间孔与椎管狭窄 口腔牙齿脱落，易造成插管困难,老年人解剖改变,MUSCULOSKELETAL,Arthritic joints may interfere with positioning (eg, lithotomy) or regional anesthesia (eg, subarachnoid block) Degenerative cervical spine disease can limit neck extension potentially making intubation difficult,消化系统,胃肠道血流量减低 胃粘膜发生萎缩 胃酸分泌减少 胃排空时间延长 肠蠕动减弱,肝脏,合成蛋白质的能力下降 血浆蛋白减少 白蛋白与球蛋白的比值降低 血浆胆碱酯酶活性明显降低 药效增强或作用时间延长,GASTROINTESTINAL FUNCTION,decrease in hepatic blood flow. Liver mass declines Plasma cholinesterase levels are reduced in elderly men. Gastric pH tends to rise, whereas gastric emptying is prolonged,萎缩 重量减轻 肾单位进行性下降 肾浓缩功能降低 保留水的能力下降,肾脏 1,肾脏 2,肾脏 3,肾脏 4,肾脏 1,肾脏 2,肾脏 3,肾脏 4,高钠血症 应激反应导致ADH过度分泌，易 发生水中毒 对电解质的调节能力下降,肾脏 1,肾脏 2,肾脏 3,肾脏 4,维持水、电解质、酸碱平衡的能力差 监测要适当 补充水、电解质计算要精确,肾脏 1,肾脏 2,肾脏 3,肾脏 4,经肾脏排泄的药物消除减慢、药物 作用时间延长 时刻调节剂量 避免使用有肾毒性的药物,RENAL FUNCTION,Renal blood flow and kidney mass decrease with age Renal function as determined by glomerular filtration rate and creatinine clearance is reduced The combination of reduced renal blood flow and decreased nephron mass increases the risk of elderly patients for acute renal failure in the postoperative period,As renal function declines, so does the kidneys ability to excrete drugs elderly patients are more predisposed to developing hypokalemia and hyperkalemia,易并发糖尿病 血浆醛固酮浓度降低，易出现高血钾 甲状腺功能降低 甲状旁腺素升高，降钙素降低，易发生骨质疏松 应激能力有一定的减弱,内分泌系统,METABOLIC & ENDOCRINE FUNCTION,Basal and maximal oxygen consumption declines with age Heat production decreases, heat loss increases,甲状腺功能减低、交感系统活性下降,基础代谢和体温调节,基础代谢率降低,注意体温监测 注意保温,药理特点,药理特点,脂溶性药物分布容积大，作用时间延长 血浆白蛋白减少，血浆内游离型药物浓度增加 肝脏酶水平下降，肝血流减少，影响药物代谢速度 肾脏排泄功能减低，药物作用时间延长,药代学特点,药代学特点,对兴奋性药物不敏感 对抑制性药物敏感 对全麻药物敏感 全麻药物药效增强,血浆蛋白结合减少,药代和药效的差别,白蛋白含量减少，蛋白质量下降，两种以上药物同时使用时，能影响麻醉药与蛋白结合 与蛋白结合减少，导致游离药物水平上升，促进药物作用于脑 老年人脑与血浆药物浓度差异比青年人小,单次给药后，老年和青年药物血浆和脑内浓度的曲线 （老年血浆浓度曲线较青年高，初起因容积分布较小， 随后因药物代谢较慢，老年人脑对药物较敏感，药物 作用时间延长）,药效增加 半衰期延长,血浆白蛋白减少 血浆结合蛋白质能力减弱 同时服用多种药物抢占了结合位置 疾病使结合能力下降,身体组成改变,骨骼肌减少，脂肪增加，血容量下降20%30% 麻醉药进入血浆浓度老年人比青年 高，脂溶性高药物易潴留在脂肪内，排泄推迟，作用时间延长，半衰期明显延长,肝肾功能减退,肝、肾功能减退，30岁开始每年1% 肾血流下降伴肾小球功能减少，肾小球滤过率60%，排空延迟 药物血浆浓度下降迟缓，半衰期延长,药 物 青 年 老 年 芬太尼 250min 925min 阿芬太尼 90min 130min 地西泮 24h 72h 咪达唑仑 1.8h 4.3h 维库溴胺 16min 45min,老年和青年各药的半衰期,中枢神经系统,神经原减少，脑血流和脑氧代谢下降 对麻醉药需要量减少 初始分布容量下降，镇痛药、巴比妥类用量仅为4050岁的70%,AGE-RELATED PHARMACOLOGICAL CHANGES,Decreased total body water The reduced volume of distribution An increased volume of distribution changes in volume of distribution Elimination half-life will be prolonged Renal and hepatic functions decline with age Altered plasma protein,INHALATIONAL ANESTHETICS,The MAC for inhalational agents is reduced by 4% per decade of age over 40 years The myocardial depressant effects of volatile anesthetics are exaggerated in elderly patients Recovery from anesthesia with a volatile anesthetic may be prolonged The rapid elimination of desflurane may make it the inhalation anesthetic of choice for elderly patients,NONVOLATILE ANESTHETIC AGENTS,Elderly patients display a lower dose requirement propofol cause apnea and hypotension Both pharmacokinetic and pharmacodynamic factors are responsible for this enhanced sensitivity,NONVOLATILE ANESTHETIC AGENTS,Elderly patients require nearly 50% lower blood levels of propofol for anesthesia than younger patients thiopental sensitivity appears to be primarily due to pharmacokinetics factors,Opioid,sensitivity to fentanyl, alfentanil, and sufentanil is primarily pharmacodynamic Dose requirements for the same EEG end point using fentanyl and alfentanil are 50% lower in elderly patients volume of the central compartment and clearance are reduced for remifentanil,Benzodiazepines,diazepam the elimination half-life can be as long as 3672 h Midazolam requirements are generally 50% less in elderly patients; its elimination half-life is prolonged from about 2.5 to 4 h Lorazepam is less lipid-soluble than diazepam the elimination half-life unchanged,局 麻 药,用药量减少 药物易于扩散： 细胞膜通透性改变、脱水、局部血流减少和结缔组织疏松 药液不易向椎间孔扩散，停留在硬膜外腔,MUSCLE RELAXANTS,Decreased cardiac output and slow muscle blood flow, however, may cause up to a 2-fold prolongation in onset of neuromuscular blockade in elderly patients,肌肉松弛剂,阿曲库铵Holfman消除，不影响 琥珀胆碱胆碱酯酶水解，需要量少 泮库溴铵经肾排除，需要量少 维库溴铵经胆汁排除，有时需要量少,肌肉松弛剂的拮抗,不减少拮抗药的剂量,注意拮抗药的副作用,年龄相关性疾病,心脏病、肾功不全、糖尿病和痴呆,年龄引起的功能减退,颅内、胸内和腹腔内手术比四肢 和体表危险性大,老年病人麻醉手术 风险 因素,老年病人麻醉前评估和准备,了解全身情况,各系统功能状态,营养状态,并存疾病,精神状态,目前用药对围术期影响,老年病人麻醉前准备,执行各项准备措施 充分治疗并存疾病 改善各系统功能 力求达到最佳水平 尽量减少并发症、提高成功率,心血管系统评估和准备,充血性心衰、心肌梗死，行急诊手术 冠心病应用药物治疗，术前不停药 高血压力求控制，舒张压110mmHg应延期手术 心动过缓应排除病窦综合症 心律失常要警惕,呼吸系统评估和准备,找危险因素 肺功和血气检查 尽量改善肺功能 控制呼吸道感染 进行呼吸功能锻炼 减少分泌物,肺功和血气检查适应症,大量吸烟 咳嗽合并呼吸困难 70岁以上 有肺部疾病 有术后并发症史 肥胖 胸或腹腔手术 严重神经肌肉或胸壁疾病,中枢神经系统评估和准备,脑血管疾病及并存疾病 帕金森病,限制性通气障碍、阵发性膈肌痉挛 分泌物增多 体位性低血压 麻醉期间血压易波动 不应停药,糖尿病病人评估和准备,积极控制血糖 空腹不易超过8小时 术中监测血糖 低血糖及时补充（1U：24g葡萄糖） 血糖超过14mmol/L，胰岛素510U静注,骨关节病变,困难插管 药物影响凝血功能 肾上腺皮质危象,麻醉性镇痛药剂量应减少,镇静催眠药剂量应减少,抗胆碱类不作为常规,美国ACC/AHA（2002）围术期心血管危险性评估,围术期心血管高危因素,高危 1.不稳定型冠状动脉综合征：心肌梗死，不稳定型或严重心绞痛 2.失代偿心衰及严重心律失常：重度房室传导阻滞及心脏病伴明显的室性心律失常，室上性心律失常而室率不能控制,心源性死亡5%,中危 1、轻度心绞痛 2、心肌梗死病史或Q波异常 3、代偿性心衰或有心衰史 4、糖尿病（胰岛素依赖型） 5、肾功能不全,心源性死亡5%,低危 1、高龄 2、ECG示左室肥大、左束支传导阻滞、ST-T 异常 3、非窦性心律（房颤） 4、心脏功能差（不能上楼） 5、脑血管意外史 6、不能控制的高血压,心源性死亡1%,手术危险性评估,高危 中危 低危 急症大手术 动脉内膜剥脱术 内腔镜手术 心脏瓣膜手术 头颈部手术 白内障手术 大血管手术 胸腔手术 乳房手术 长时间手术（3h）腹腔手术 电休克治疗 大量失液和失血 大关节置换术 体表手术 前列腺活检,心功能状态用代谢当量 （metabolic equivalent,MET)评估,MET 静息时无不适 MET 自行穿衣、进食、上厕所 MET 室内或室外散步 MET 4km/h 步行200500m 平路，作轻便家务如揩灰、洗碗等 MET 能上1、2层或登小山坡,MET 6.5km/h,步行 MET 短程小跑 MET 从事较重家务如拖地板、搬家具 910 MET 参加保龄球、跳舞、中度体育活动 10以上MET 参加游泳、网球、足球等剧烈活动,1MET相当于 男40岁,70kg,静息状态下氧=3.5ml/kg/min,优良 7MET以上 中等47MET 差4MET以下,美国ACC/AHA（2002）决定可否手术的八项顺序,第1步 心脏病人急症非心脏手术经必要准备可立即实施，但选择性手术应进入第2步评估 第2步 在5年内施行过CABG的病人，应判断其有否复发及心肌缺血症状，若无则可施行手术，否则进入第3步评估 第3步 最近冠心病病情评估，冠状动脉造影及应激试验证明无心肌缺血可施行手术。如有心肌缺血或未经上述检查则进入第4、5步评估,第4步 高危病人已行冠脉造影及内科治疗，应进 一步了解病情轻重程度及治疗情况，如未造影或 内科治疗者，应推迟手术，并进行检查治疗，改 善高危病人全身情况,第5步 中危病人进入第6步，低危病人进入第7步,第6步 中危病人有心绞痛和心肌梗死、心衰病史、糖尿病或肾衰病史，则应根据全身耐受情况评定：4METs，全身情况较好的病人，中危和低危病人可施行手术，高危应进一步检查、评估和治疗,第7步 全身情况较好或低危病人（年龄4METs，可施行手术 第8步 符合条件进入第8条，可以施行手术,决定手术的因素:, 急症或择期手术； 心脏危险因素； 内科治疗或CABG史，需进一步检查或治疗； 全身耐受情况（METs）； 手术危险性（范围大小，时间长短及出血多少）,推迟手术的因素：,高危因素或伴有全身耐受力差的中危因 素的病人 低危因素+全身耐受力较差的病人 中危因素+全身耐受力中等+重危手术的 病人,维 持,麻醉和手术中的生理状态,细胞供养/需氧平衡,液体平衡,血流动力学稳定,麻醉方法选择,局麻或神经阻滞 体表、颈、上肢手术 脊麻和硬膜外麻醉 下肢、下腹及外阴手术 全身麻醉 上腹、胸内、颅内手术及全身情况差,麻醉中监测,BP,HR,RR,SpO2，尿量 麻醉药浓度监测 麻醉气体监测 体温监测 有创血压、CVP 肌松监测,做好术前评估，正确了解重要脏器功 能 积极术前准备，最大限度改善病理状态 选择对生理功能扰乱小的麻醉 选择对呼吸、循环干扰小的药物 注意药物的半衰期及排泄时间,麻醉诱导期,诱导药缓慢静推，少量递增 注意松动牙齿 减少插管应激反应 注意骨质疏松，避免骨折 注意体位性低血压,维持麻醉和手术中的生理状态 注意重要脏器功能 满足手术需要 抑制手术引起的有害反射 做好充分镇痛 麻醉不宜过深但避免术中知晓,麻醉维持期,恢复呼吸 注意通气、呼吸道梗阻、缺氧 肌松剂拮抗 阿片类药物拮抗 注意镇痛,术毕苏醒期,死亡率,避免急症手术 改善营养，术前及早治疗并存病，改善全身