胸腹主动脉瘤手术的麻醉处理

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,*,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,*,胸腹主动脉瘤手术的麻醉处理,中山大学附属第一医院麻醉科,夏杰华,一、腹主动脉瘤病因及发病机制,1.吸烟,烟草燃烧产生的气态物质进入血液，可将,蛋氨酸氧化成蛋氨酸亚砜，蛋白水解酶活性,增加，加重了动脉壁,弹力蛋白,的降解，引起,动脉壁力量减弱而导致动脉瘤的形成。,2.高血压,与发病率和破裂的危险性有密切的关系,3.年龄因素,动脉壁的弹力蛋白纤维随年龄的增长出现降解、,断裂和钙化，使动脉壁难以承受血压的冲击而发,生动脉瘤。,4.炎症反应,慢性炎症反应中的巨噬细胞和活化的,T、B,淋巴细,胞可刺激金属蛋白酶的产生，促进结缔组织的降解，,削弱和破坏主动脉壁中层，导致产生动脉瘤。,另有研究认为,雌激素,水平是动脉瘤的产生的原因之一,:,在腹主动脉瘤形成的过程中雌激素可能通过降低组织基质金属蛋白酶,2,、,9(,MMP-2,、,9),的,mRNA,表达、蛋白合成,从而延缓动脉瘤的形成,.,-,国外医学,-,二、腹主动脉瘤的病理改变,1.真性动脉瘤：动脉粥样硬化是常见原因。,动脉粥样硬化的危险因素：高胆固醇血症、糖尿病、肥胖、,高血压、吸烟史，男性，等等。,2.假性动脉瘤：多见与动脉损伤。,3.夹层动脉瘤：动脉壁中层囊性坏死或退行,性变。,三、诊断,腹部搏动性包块,神经压迫症状,下肢缺血症状,血管造影、,CT、MRI、,高速螺旋,CT,等,影像学检查,四、胸腹主动脉瘤的手术方式及概况,手术方式：,1.,Open repair,2.Medal graft stent,3.Baloon-expandable,4.Hand-help laparoscope repair,Elective surgery by open transperitoneal or retroperitoneal,approach is the most common repair intervention. However,placing an endoluminal stent graft within the aneurysm is,currently being evaluated as an alternative to open repair.,J-Cardiovasc-Nurs. 2001 Jul; 15(4): 1-14,Newer, minimally invasive catheter-based endovascular,technology utilizing stent grafts are currently being evaluated,for abdominal aortic aneurysm (AAA) repair.,Vasc-Surg. 2001 Sep-Oct; 35(5): 335-44,平均年龄,68.5 +/-7.7 years.,高血压病史,55%,心脏病,73.5%,外周血管疾病,21%,中风和短时间缺血,22%,糖尿病,7%,肾功能不全,10%,吸烟史,80%.,Vasc-Surg. 2001 Sep-Oct; 35(5): 335-44,Complications:,Complication rates varied widely among hospitals. Complications,independently associated with increased risk of in-hospital death,include cardiac arrest , septicemia , acute myocardial infarction,acute renal failure , surgical complications after a procedure , and,reoperation for bleeding .,The population-attributable risk for in-hospital mortality was,47% for cardiac arrest and 27% for acute renal failure.,Langenbecks-Arch-Surg. 2001 Jul; 386(4): 249-56,五、麻醉方法及术中处理,全身麻醉、硬膜外麻醉以及联合麻醉等各种麻醉技术与麻醉药物都已成功应用于开腹,AAA,修补术。,其中的联合麻醉方式通常是指联合应用高腰段或下胸段硬膜外麻醉与浅全麻的复合麻醉方式。,对于术前服用抗凝药物的病例处理,1,、药物术前停用：阿司匹林,37,天，波立维（氯吡格雷）,57,天，华法林,45,天。,2,、评估出血风险：目标，术前,INR1.5,。,3,、,Bridging,的注意事项：,Bridging,需在华法林最后一次使用的,48h,开始；治疗剂量的低分子肝素（,LMWH,）应在术前,24h,停用；栓塞的高风险患者应在术后,48h,内启用治疗剂量的,LMWH,。,Procedures performed before anesthesia:,Collection and storage of patient,，,s own,blood in the weeks preceding surgery.,Prescribe premedication.,A warming blanket is necessary in the,anesthetic room.,Mornitoring.,Procedures performed before surgery starts:,1.,A suitable vein or veins are cannulated with,at least one 14-gauge cannula for infusion of,warmed fluids.,2.Cannulation of a radial artery.,3.Central venous catheterization for measure-,ment of right atrial pressure.,4.An oesophageal or tympanic membrane,temperature probe is inserted for measure-,ment of temperature.,5.,The bladder is catheterized for monitoring of,urine output.,Key points,during anesthesia and operation,procedure.,1.Tracheal intubation,To maintain systemic arterial pressure stable.,(Dopamine or Noradrenalin),The double lumen tubes are necessary for some,thoracic approach operations,2.,Crossclamping of the aorta,a sudden increase in systemic vascular resistance,(afterload): cardiac work increase,myocardial ischaemia,the large bowel and lower limbs suffer variable degrees of hypoxia:,inflammatory mediators released,oxygen radicals,neutrophil proteases,platelets activating factor,cyclo-oxygenase products,cytokines,3.,Aoric declamping,a sudden decrease in afterload with reperfusion,of the bowel, pelvis and lower limbs.,vasodilatation,metabolic acidosis,capillary permeability increased,blood cells sequestrated in the lungs,4.,The large heat loss,Many patients undergoing this operation are,elderly and have a low metabolic rate.,All possible measures must be taken to minimize,heat loss.,(1)Warming of infusion fluids,(2)Warming and humidification of anesthetic gases,(3)Use a warming blanket,(4)Wrapping the bowel in a clear plastic bag,(5)The operating theatre,Organ protection,Vascular diseases are associated with these disorders:,Diabetes(,糖尿病),Smoking sequelae(,吸烟后发症),COPD(,慢性阻塞性肺病),Hypertension(,高血压),Renal insufficiency(,肾功能不全),Ischaemic heart disease(,缺血性心脏病),术中器官保护,心肌及心脏功能保护,Decrease myocardial oxygen demand,Decrease heart rate,Decrease myocardial contractility,Decrease LV end-diastolic volume,Decrease afterload,Increase myocardial oxygen supply and coronary,blood flow,Decrease vasoconstriction,Decrease thrombosis,Increase diastolic time,Increase diastolic pressure,Decrease LV end-diastolic pressure,Increase oxygen saturation.,Drugs,. Mannitol has a positive effect in countering these,deleterious pulmonary effects.,神经保护,缩短主动脉钳夹时间,局部脊髓低温（32-34,o,C）,维持最大限度的高血压状态和术后灌注压,细胞膜稳定药物、抗缺血-再灌注损伤和减轻全身,炎症反应,脊髓缺血监测：血糖监测，唤醒，皮层诱发电位,脊髓保护,据报道,OAR,术后截瘫及轻瘫发生率为,5% 40%,。手术时主动脉阻断时间长短是影响术后截瘫发生的一个重要因素,主动脉阻断时间,60 min,时发生率为,25% 100%,。,- Eur JCardiothorac Surg, 2001, 19(2): 203-213.,脊髓保护,非体外循环下动脉瘤手术是否发生截瘫或肾功能衰竭，最重要的单一决定因素就是主动脉阻断时间。,2030min,内几乎不发生截瘫。,3060min,为易损期，截瘫的发生率随着阻断时间的延长由,10%,上升至,90%,。,-Miller,s Anesthesia edition,脊髓保护,脊髓损伤的防治包括,:,缩短脊髓缺血时间,:,研究证明主动脉阻断的最安全时限为,30 min;,脑脊液引流,:,降低脑脊液压力,提高脊髓灌注压,;,术中低温技术：,低温可减少神经组织的需氧量,降低组织代谢率,稳定细胞膜,增加组织对缺血耐受性,减少兴奋性递质释放,从而达到间接保护脊髓目的,应用保护性药物,:,包括超氧化物歧化酶、糖皮质激素、类固醇、镁离子等。,肾脏功能保护,缩短阻断时间,保持足够的有效的循环血容量,避免过量的血管扩张药物并保持最大限度的,高血压状态,多巴胺的连续输注,肾功能保护,有许多不同的肾脏保护方法被采纳,多数集中于改善肾脏或肾小管血流。其中包括,:,多巴胺,(,多巴胺受体剂量,23g,kg-1,min-1),。,另外，,ACE,阻滞剂、前列腺素、卤化药物、胸部硬膜外以阻滞肾动脉交感神经、血管扩张药,等容量血液稀释,(,在血管阻力升高的情况下增加血流,),、速尿和甘露醇等。,SrpArhCelokLek, 2002,130(5-6): 168-172,.,麻醉处理,诱导：,Midazolam , Propofol,Fentanyl,Vecuronium, Tracurium,各种有创监测操作,胃管，尿管的停留,麻醉的维持,:,复合麻醉,术中的药物使用：心功能的支持与加强（多巴胺、西地兰、,磷酸肌酸）,抗炎症反应与再灌注损伤（乌司他丁、甲基强的松龙、,甘露醇,），肾功能保护（速尿）,纠正酸中毒。,4. 复苏与镇痛,术中监测,AAA,术中应常规监测,ECG,、,MAP,、,CVP,、,SpO2,、,HR,、体温,(,鼻温、肛温,),、血气、电解质及尿量。通过标准心电图,(ECG),、经食管超声心动图,(TEE),和肺动脉导管,(PAC),监测心肌缺血,降低心脏发病率。,TEE,可评估左心室壁异常运动,并在心肌缺血存在、心电图,ST,段改变之前探察到收缩期心室壁异常增厚。,J CardiothoracVascAnesthesia, 2003, 17(6): 703-708.,术中监测,临床研究存在许多矛盾结果,随机化控制试验显示,AAA,修补术患者实施,PAC,监测没有任何临床价值,而,PAC,监测是否应该选择性地应用于高危的复杂主动脉重建术患者尚有待评估。,N Engl JMed, 2003, 348(1): 5-14.,输血与容量管理,应根据术中出血量、红细胞压积,(Hct),和活化部分凝血激酶时间,(APTT),指导输血。研究表明等容血液稀释和自体血净化回输可显著减少异体血的需要量以及引发的输血反应。,J Vasc Surg, 2002, 36(1): 31-34,.,输血与容量管理,值得注意的是,除非血压过低或低血压持续时间过长,应避免应用大剂量的血管收缩药,防止因吻合口漏需再次钳闭动脉时出现的,“,反跳性,”,高血压。,J Vasc Surg, 2002, 36(1): 31-34,.,关于腔内修复,EVAAR,术中患者血压在保证心、肺、肝、肾、脑等重要脏器血供的前提下,应维持在较低的水平,一方面减少股动脉切开处的出血,更重要的是支架锚定在动脉管壁时,过强的血流使支架不易定位。,DSA,下,EVAAR,麻醉管理的特点,1,、术中大部分时间不能近距离管理病人,2,、手术创伤相对小，麻醉药物的选择更偏向短效，小剂量,3,、胸段支架开放时对心脏有较大的后负荷压力,4,、一般选择右侧桡动脉穿刺测压，有时可能需要左右或上下两点测压,5,、肌松状态要求不高，但须保证术中病人处无体动状态,此外,，,腔内修复手术病人复苏期问题也应充分关注。,谢 谢！,