胃肠外营养

胃肠外营养 (Parenteral nutrition, PN ),浙江大学医学院附属邵逸夫医ICU 潘孔寒,1986年2月，上海周绮思女士因患急性肠扭转切除全部小肠，华瑞决定长期无偿向提供生存所需的全套全静脉营养产品.,1992年4月8日，历史将记住这一天。蔡惟成为世界上完全依靠人工全静脉营养孕育的第一人。周绮思母女的事例也因此被载入吉尼斯世界纪录。,References,History of parenteral nutrition. JPEN， 27:225-232, 2003 A.S.P.E.N. Board of Directors and the Clinical Guidelines Taskforce: Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN， 26(Suppl):1138,2002Canadian Clinical Practice Guidelines for Nutrition Support in Mechanically Ventilated, Critically Ill Adult Patients. JPEN， 27:355373, 2003危重患者营养支持指导意见（草案）(中华医学会重症医学分会).中国危重病急救医学,10(18)：582590,2006 住院患者肠外营养支持的适应证（草案)(中华医学会肠外肠内营养学分会).中国危重病急救医学,10(18)：591594,2006,循证医学：证据分级,A级 以良好研究为基础的证据来支持指南 (前瞻、随机试验)B级 以较好研究为基础的证据来支持指南 (设计较好但无随机化)C级 依据专家观点和共识来制订指南,Contributors,Jonathan Evans Rhoads, MD, Surgical Nutritionist the Harrison Department of Surgery at the University of Pennsylvania Stanley Dudrick, MD, Henry Vars, PhD, Douglas Wilmore, MD, and others at the University of Pennsylvania The full development of parenteral nutrition, as we know it today, was dependent on endless hours of effort by dedicated nurses, pharmacists, and dietitians.,History,Complete parenteral or IV nutrition is a therapeutic method that has been available for approximately 50 years The successful development of this mode of therapy, in a modern sense, was initiated in the late 1930s, but its practical clinical use did not emerge until the 1960s.,History1,The discovery of the circulation of the blood by William Harvey in 1628 formed the basis for the rationale for IV injections and infusions. A decade later, an important contribution to the development of IV infusions was made during the severe cholera epidemic of 1831 to 1832 by the Scottish physician Latta.He was the first to infuse water and salts (saline) into a patient, who quickly recovered and survived.,History2,Edward Hodder, in Canada in 1873, infused fat in the form of milk into 3 cholera patients. Two of the patients recovered completely, but the third cholera patient did not survive despite the milk infusion.,History 3 STUDIES WITH GLUCOSE,It seems obvious in retrospect that the field of parenteral nutrition could not progress successfully before much more was known in the basic sciences. Arthur Beidl and Rudely Krauts, in 1896, were the first to infuse glucose IV in humans. The terms glucose fever and salt fever,History4 STUDIES WITH GLUCOSE,In 1915, Woodyatt and co-workers reported studies on IV administration of glucose in humans. They reported that about 0.85 g of glucose/kg per hour could be supplied by IV without ensuing glucosuria. This classic early study predated glucose clamp investigations by more that 50 years. They stated: IV nutrition with glucose is thus proved to be a feasible clinical proposition, and the way is opened for experiments with amino acids, polypeptides, etc.,History5 STUDIES WITH GLUCOSE,Matas, in 1924, was the first to use a continuous drip infusion of glucose, and some years later, Zimmerman, in 1945, described the infusion of IV solutions through an IV catheter placed in the superior vena cava.This approach was used by Dennis and Dennis and Karlson, who reported the support of surgical patients with the continuous infusion of a solution of 20% glucose along with some vitamins, electrolytes, and 300 to 400 mL of plasma.,History6 STUDIES WITH GLUCOSE,The next major contribution was the infusion of hypertonic glucose and all necessary nutrients by Dudrick et al.,History 7 The Use of Plasma as a Protein Source,In 1946, Albright and his research team at the Massachusetts General Hospital in Boston investigated the metabolic fate of infused plasma protein in humans and demonstrated that such infusions contributed to positive nitrogen balance.,History8 PROTEIN HYDROLYSATES AND CRYSTALLINE AMINO ACIDS,Robert Elman, a surgeon who worked in St Louis In 1937, he published the first successful studies evaluating the IV infusion of amino acids in the form of a fibrinogen hydrolysate in man.This was an indisputable landmark in the development of IV nutrition . Undoubtedly, Elman deserves the complement given to him by Arvid Wretlind, who referred to him as the father of IV nutrition.,History9 Fat,It was realized early on that optimal use of the amino acids in solutions could only be achieved by simultaneously providing adequate amounts of necessary energy. In those days, glucose was the only available nonprotein source that could be given IV.,History10 Fat & parenteral nutrition,The first to develop a nontoxic readily available fat emulsion was the Swedish scientist Arvid Wretlind, who in 1961, introduced Intralipid together with O. Schuberth. For his many developmental contributions, it seems appropriate to call Arvid Wretlind the father of complete parenteral nutrition,History11 Parenteral nutrition,In 1962, one of the first symposiums on parenteral nutrition was held in Kungalv, Sweden. This was the first time details of a TPN program were presented.,History12 Parenteral nutrition,In 1968, a new landmark in the history of parenteral nutrition was passed by Dudrick et al, who demonstrated that a catheter placed in the superior vena cava could be used over extended periods of time to administer a solution of concentrated glucose, along with all other essential nutrients.,History13 Parenteral nutrition,Dudrick et als regimen : Glucose system The Swedish regimen : Fat systemRhoads : Hyperalimentation,History14 Parenteral nutrition & HPN,A contemporary parenteral feeding program consists of water, energy (carbohydrates and fat), amino acids, vitamins, and trace elements. It is extremely important that these nutrients are administered together. An improvement, aimed to simplify the infusions, was the introduction of the All-in-One system, where all nutrients are mixed in 1 bag at the local pharmacy or at a pharmaceutical company. The method was introduced by Solassol et al in 1972.,专用营养支持(SNS)应用流程图,营养评估,胃肠功能,有,EN,胃肠功能,特殊配方,标准营养素,受限,正常,部分PN补充,过渡至EN,营养素耐受,适时过渡至经口喂养,适时过渡至全面的配方及经口喂养,无,PN,短期,外周PN,胃肠功能恢复,中心PN,长期或液体限制,无,弥漫性腹膜炎肠梗阻顽固性呕吐肠麻痹顽固性腹泻胃肠缺血,营养筛查,营养不良定义 营养状态紊乱，包括营养摄入缺乏、营养代谢障碍、 营养过度。营养不良发生相关因素 病人病前状态，营养摄入不足的程度和时间，并发 其它疾病。营养不良发生率 3055%住院病人 重症病人，不管用什么方法评估，都将被定 为营养不良。,营养筛查,营养不良后果死亡率和患病率升高创口愈合延迟并发症发生率升高再住院率升高住院时间延长、费用升高,营养筛查,参数 正常范围 轻度 中度 重度体重 (%) 90 8090 6079 90 8090 6080 90 8090 6079 95 8594 7084 30 3025 24.920 2 1.62.0 1.21.5 1500 12001500 8001200 800氮平衡(g/l) +1 5 10 10 15 15,营养筛查,主观全面评定 subjective globe assessment,SGA微型营养评估 mini nutritional assessment, MNA营养不良风险筛查2002 nutrition risk screening NRS2002,SNS的应用,SNS 以治疗为目的，经口、经胃肠或经胃肠外提供营养EN 通过置入胃肠的管道 非意愿地提供营养PN 通过静脉提供营养条件 非急诊措施，需在患者血流动力学稳定后起用。,SNS的应用,最大的争议：PN和EN的相对适应症认为：不接受EN的危重病人可能会经历肠内菌群移位(translocation of intestinal flora)及相关的内毒素释放，从而激活炎症通路（inflammatory pathways）。认为： 多系统器官衰竭的病因、进展及死亡与上述产生的全身炎症激活有关。但至今，很少有关人类的资料来证实这点。EN 似乎能帮助维持肠道的粘膜结构和功能。,SNS的应用,没有充足的随机、前瞻、对照试验作荟萃分析来比较EN和PN在各种疾病中的应用情况，所以不能明确在许多疾病中EN较PN的优越性许多研究表明：PN较EN容易达到营养治疗目的，且即使在胃肠功能良好的情况下，只有PN才能取得合适SNS。,SNS的应用,另一争议起用SNS的理想时机已有建议：疾病早期使用EN可减轻应急反应，提高耐受性。报道：术后6-12h对EN的耐受性很好，但这只提供了可行性，并没说明有必然的益处。,SNS的应用,何时起用PN复杂，常被问及的问题无相关的前瞻，随机临床试验2个试验入院后或手术后1014天不进食或无SNS患者较差的临床结果，较长的住院时间，较高的医疗费用故可起用SNS已有714天经口摄食不足或估计714天经口摄食不足的患者,SNS应用实践指南,SNS用于不能通过经口来满足营养需求的患者。（B）需用SNS时，EN优于PN 。（B）需用SNS时，PN用于胃肠功能不佳或不能使用或经口或EN不能提供合适营养的患者。 （B）患者已有714天经口摄食不足或估计714天经口摄食不足的患者可起用SNS 。 （B）,成人正常需要,SNS营养需求量应根据正规的个体化营养评估结果而定。每种营养成分的需求应随营养状态，疾病，器官功能，代谢状况，使用的药物，营养支持的时间而变化。没有标准EN和PN配方。调查表明患者常常接受提供多余能量的配方。,成人正常需要,补充的热卡应恰当地满足基础的能量消耗，并提供满足一定水平的体力活动，从而维持健康体重指数。正常成人能量需求2035kcal/kg/d ( 85145kj/kg/d)糖7g/kg/d, 脂肪2.5g/kg/d(165cm=身高-100165cmMale: 身高-105Female: 身高-100,成人正常需要,正常人体能量的需求Harris-Benedict公式 男：BEE(kcal/d)=66.4730+13.7513W+5.0033H-6.7750A 女：BEE(kcal/d)=655.0955+9.5634W+1.8496H-4.6756A碳水化合物：3570的非蛋白热量，7g/kg。脂肪：2030的非蛋白热量，应激状态可达50，=体表面积40% 2.0 肌肉做功活动 1.1-1.25 发热 1.05-1.10/度,成人正常需要,确定蛋白质需要量1g氮=6.25g蛋白质正常蛋白质需要量: 约1g/kg/d在有前述多种应激时，乘上系数热氮比: 所需能量(kcal)/150=所需氮量, 即1:150配方(每150kcal非蛋白热量需氮1g),成人正常需要,碳水化合物：占60%。TPN最佳输注速度：4-5mg/kg/min标准TPN含21%的葡萄糖危重病人最大可达400-500g/dDM、COPD病人适当减少透析病人可从透析液中吸收大量葡萄糖，可据情况减少用量,成人正常需要,脂肪：3%-30% 在脓毒症病人可达40%-50%。碳水化合物:脂肪 热量最佳比例 70:30,胃肠外营养途径实践指南,PN应通过一远端位于上腔静脉或右心房的导管提供 （A）置管后应摄胸片，除非用放射介入技术经由颈内或上肢静脉置入 （B）置放中心静脉导管时应采取全面无菌措施 （B）操作前应用Chlorhexidine 消毒皮肤 （B）使用前和抽血前hub应消毒 （C）不必常规经导丝更换导管 （A）高危病人和高危医疗场所（感染率高）推荐使用抗菌导管（B）长期置管患者应使用低剂量抗凝药 （B）由经特殊培训的护理小组管理接受PN治疗的患者的静脉管路 （B）,疗效监测实践指南,在SNS治疗期间应定期监测营养参数(氮平衡、血清蛋白和能量平衡)和临床结果(生活质量、患病率和死亡率、住院时间和住院费用)。(B) 定期比较营养参数/临床结果和SNS冶疗目标，及时修改营养处方。 (C),肠内及肠外营养并发症,再喂养综合征： 低磷、低钾、低镁、水钠潴留高糖血症和低糖血症代谢性酸中毒高甘油三酯血症二氧化碳产生过多,肠内及肠外营养并发症,肝胆并发症（PN）代谢性骨病导管性脓毒症(PN)食管反流和误吸(EN)呕吐、腹胀、腹泻(EN)过度喂养并发症,并发症监测实践指南,起用SNS时，有再饲综合征(refeeding syndrome)危险的营养不良患者应仔细监测血清磷、镁、钾、糖水平。 (B)糖尿病患者或有不耐受糖危险的患者起用SNS时，应减慢输注糖的速度，同时严密监测血糖、尿糖。 (C)一经起用SNS，胰岛素量调整后应经常监测血糖直至稳定。 (B)起用SNS时，应经常监测血清电解质(钠、钾、氯、碳酸氢盐)直至稳定。 (B),并发症监测实践指南,静脉使用脂肪乳剂或调整剂量的患者应监测血清甘油三酯直至稳定。 (C)接受PN患者应定期监测肝功能。 (A)起用SNS时，应测量骨密度并作定期检查 (C) 接受EN患者有明显误吸危险时，应考虑置幽门后营养管。 (C),老年患者应用实践指南,老年患者(65岁)均处营养不良危险状态，应作营养筛查。 (B)年龄和生活方式类参数可用来评估老年患者营养状态。 (C)在接受药物治疗的老年患者应评估其潜在的药物-营养物间作用。 (B)在给老年患者开饮食或SNS医嘱时，应考虑此年龄组特殊营养物需求。 (B) 碳水化合物：55-60%；维生素B-12、B-6、C和叶酸相对缺乏；水：30ml/kg或至少1500ml/d。,肥胖患者应用实践指南,肥胖患者均处营养不良危险状态，应作营养筛查。(B)条件允许时，应用间接能耗测定法来评估肥胖患者的能量需求，因为，在评估肥胖患者的能量需求时，能量预计公式(如Harris-Benedict公式)均有较大的限制。 (B)在治疗轻度和中度应激的肥胖患者时，推荐低热卡配方(其中蛋白质：1g/kg IBW) 。 (A),糖尿病患者应用实践指南,糖尿病患者均处营养不良危险状态，应作营养筛查。 (A) 住院糖尿病患者之血糖应控制在100-200mg/dl范围。 (A)提供给糖尿病患者的EN和PN中大分子营养组分应个体化，并且避免使用过多热卡。 (B) PN：0.1u RI/1g糖,心脏病患者应用实践指南,心脏恶液质(cardiac cachexia) ：是一种发生在少数NYHA级或级充血性心衰(CHF)患者的重度营养不良综合征。包括瘦肉组织缺失(含重要器官如心脏)并导致行为状态和免疫功能下降。与生存率下降有关。伴心脏恶液质患者或CPB术后伴并发症患者均处营养不良危险状态，应作营养筛查。(B)PN限于有术后并发症且胃肠道不宜使用的心脏病患者。 (C)心脏手术患者使用EN应延至血流动力学稳定之时。 (C),肺病患者应用实践指南,COPD或ARDS患者均处营养不良危险状态，应作营养筛查。(B)肺病患者的能量摄入应控制在或低于估计需求量以减少CO2的产生。(B)不推荐肺病患者常规使用改良的低碳水化合物-高脂肪营养配方。(B)使用含n-3脂肪酸的改良肠内营养配方可能对早期ARDS患者有效。(B)容量限制型营养配方适用于血流动力学状态要求容量限制的ARDS病人。(B)应严密监测肺病患者的血清磷水平。(A),肝病患者应用实践指南,肝病患者均处营养不良危险状态，应作营养筛查。(B)肝病患者的营养评估应包括维生素A、D、E、K和Zinc。(B)肝硬化患者应分4-6次摄入每日所需能量。(B)显性肝性脑病的急性管理应包括限制蛋白的摄入(1.0g