100023 北京市2345信箱 世界华人消化杂志  1999年12月15日;7(12):1024-1028
Email: wcjd@public.bta.net.cn 世界华人消化杂志  ISSN 1009-3079  CN  14-1260/R
http:// www.wjgnet.com 版权归世界胃肠病学杂志社

⊙研究原著⊙

结直肠切除术后早期肠内营养的前瞻性研究

吴文溪  许勤  华一兵  沈历宗

南京医科大学第一附属医院胃肠外科  江苏省南京市  210029
吴文溪，1947-01-24生，江苏省无锡市人，汉族. 1970年上海第一医学院医学系毕业，学士，1981年上海第一医学院硕士，教授，外科总论教研室副主任，从事胃肠外科疾病诊治研究，发表论文50篇，主编《临床重症监护与治疗》等3部著作.
项目负责人  吴文溪，210029，江苏省南京市广州路300号，南京医科大学第一附属医院胃肠外科.
Correspondence to  Dr. Wen-Xi Wu, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road,
Nanjing 210029, Jiangsu Province, China
Tel. +86·25·6619960
Email. wuwenxi@public 1,ptt.js.cn
收稿日期  1999-09-15  接收日期  1999-11-08


Early enteral nutrition after colorectal resections: a prospective clinical trial

Wen-Xi Wu, Qin Xu, Yi-Bing Hua and  Li-Zhong Shen

Department of Gastroenterologic Surgery, the First Affiliated Hospital of Nanjing Medical University,
Nanjing 210029, Jiangsu Province, China



Abstract

AIM  To evaluate the feasibility of early postoperative enteral nutrition (EN) in colorectal surgery and compare the metabolic effects and histologic changes of colonic mucosa following EN or total parenteral nutrition (TPN).

METHODS  Patients undergone open elective colorectal resections were randomized to either early EN or control (TPN) group. Fifteen patients in EN group had a nasal-jejunal tube inserted during the operation. The enteral feeding with a formula containing fiber started within the first 24 hours postoperatively and continued for consecutive  7 days. The full load of EN provided 0.18ng/(kg·d) and 104.5kJ/(kg·d) of non-protein energy. Fifteen patients in control group received total parenteral nutrition via peripheral vein postoperatively and provided 0.10ng/(kg·d) and 101kJ/(kg·d) of non-protein energy for 7 days. Anthropometric, biochemical parameters and visceral functions were monitored. Colonoscopic examination with mucosa biopsy were taken in 6 patients of EN group and 4 patients of parenteral nutrition (PN) group preoperatively and followed up for 8 days postoperatively. The microstructure of the colonic mucosa was studied.

RESULTS  Patients in each group were well matched with sex, age, type and duration of operations. All patients in EN group tolerated the early feeding. Total lymphocyte and prealbumin level maintained stable after the nutrition support in both groups. Serum transferrin maintained stable in EN group, however, decreased significantly in TPN group. By the end of the study cumulated nitrogen balance in EN and TPN groups was (-19.2±15.7)gN/7d and (-27.6±12.4)gN/7d, respectively (P＞0.05). On the 8th day the serum level of lactate dehydrogenase (LDH) was significantly higher in TPN group than that of EN group (635±376 vs  418±147, P＜0.05). An increased alkaline phosphatase (AKP) level was observed after TPN support, but not in EN group. No difference was found in total bilirubin and transaminase level in the two groups. No bowel  anastomosis leakage  was found in both groups. There were no statistical differences in wound healing, infective complications and duration of hospitalization between the two groups. The overall cost of enteral nutrition was significantly lower than that of TPN group (P＜0.05). The audible bowel sounds and bowel movement recovered earlier in EN group than that in the control group (P＜0.05). Histologic examination showed the colonic mucosa thickness and glands density decreased after seven days of TPN, but unchanged after EN. Postoperatively no significant changes were observed in ultrastructure of the colon epithelial cell in the two groups except for reduced microvilli, less mucus secretion and water transport in TPN group.

CONCLUSION  The early postoperative enteral nutrition was well tolerated in the patients undergone colorectal surgery. In comparison with TPN the metabolic effect was similar in EN with less disturbance of liver function. The early enteral feeding with formula containing fiber may help to maintain the bowel functions and gut integrity.

Subject headingscolorectal resections; enteral nutrition; prospective study

Wu WX, Xu Q, Hua YB, Shen LZ. Early enteral nutrition after colorectal resections: a prospective clinical trial.
Shijie Huaren Xiaohua Zazhi,1999;7(12):1024-1028


摘要

目的  探讨结、直肠手术后早期肠内营养的可行性,比较肠内与肠外营养的代谢效应,并观察肠内营养对结肠粘膜组织学的影响.

方法  结直肠术后随机分为早期肠内营养(enteralnutrition,EN)和全肠外营养(TPN)组,各15例.EN组术后24h内经鼻肠管滴注能全力(nutrisonfiber),TPN组经外周静脉进行,两组基本等热量,各7d.术前及术后8d进行人体测量,生化监测、留取结肠粘膜标本行光镜及透射电镜观察,并比较肠功能恢复及住院费用等.

结果  EN组15例均完成肠内营养计划,未发生吻合口瘘和腹腔感染.两组术后体重、三头肌皮褶厚度、上臂周径、清蛋白均较术前略低(P<0.01),两组总淋巴细胞计数、前清蛋白营养支持前后无显著差异(P>0.05),转铁蛋白TPN组术后8d(2.3±1.1)g/L显著低于术前水平(3.4±1.6)g/L,
P<0.01,而EN支持组仍维持在术前水平.碱性磷酸酶TPN组术后(163±120)U/L高于术前(125±97)U/L,P<0.05,而EN支持前后无明显改变,术后乳酸脱氢酶TPN组(635±377)U/L高于EN组(418±147)U/L,P<0.05,转氨酶组间比较无显著差异,总胆红素TPN,EN前后均无显著改变.两组术后氮监测1wk均表现为负氮平衡,且累积氮平衡TPN组略低于EN组(P>0.05).EN组肠功能恢复快(P<0.05).两组伤口愈合情况、住院天数无差异
(P>0.05).平均住院费用/药物费用EN组低于TPN组(P<0.05).EN前后结肠粘膜层厚度、腺体分布没有明显变化,细胞的超微结构保存良好,TPN组术后标本镜下表现为粘膜层变薄,腺体排列稀疏,细胞超微结构除微绒毛稀少,细胞器的发达程度略受影响外,其余变化不明显.

结论  结、直肠术后早期肠内营养是安全可行的.EN和TPN均可改善患者营养状况,降低蛋白质分解,术后短期应用代谢效应相似.与TPN相比,EN促进肠功能恢复,降低住院费用,减少对肝功能的影响,维持肠粘膜组织结构的完整,有助于保护肠粘膜屏障.

主题词  结直肠切除术;肠内营养;前瞻性研究

吴文溪, 许勤, 华一兵, 沈历宗.结直肠切除术后早期肠内营养的前瞻性研究.世界华人消化杂志,1999;7(12):1024-1028



0  引言

胃肠道手术后，消化道功能受影响，术后常需禁食，围手术期营养支持受到关注. 近年来消化道动力学研究的深化，使术后早期肠内营养(EN)受到重视，但仍有问题有待探讨：结、直肠手术后消化道远端肠吻合口的存在，使术后早期EN的安全性、有效性及临床价值有进一步探究的必要. 术后早期EN，肠外营养(PN)对结肠粘膜组织学的影响，报告甚少. 我们以大肠癌术后患者为对象，比较术后早期EN与PN的临床效果，并观察大肠粘膜组织结构的变化.

1  材料和方法

1.1  材料  选自1998-09/1999-02间我科收治的结、直肠癌手术患者30例，男20例，女10例；平均年龄56.4岁±14.6岁. 无明显肝、肾功能障碍及代谢性疾病. 患者按序随机分为早期肠内营养组(EN组)和全肠外营养组(TPN组)，各15例. 两组性别、年龄、手术种类无差异.

1.2  方法  病例经3d常规术前肠道准备后手术，手术当日常规静脉补液，术后1d起开始EN或TPN. EN组：术中将鼻肠管送过幽门置于十二指肠降部以远，术后24h内开始肠内营养. 使用液体型含有纤维的肠内营养制剂能全力，术后1d经鼻肠管滴入生理盐水500mL，及能全力500mL，速度50mL/h～75mL/h. 术后2d能全力1000mL，75mL/h～100mL/h.  3d～7d能全力1500mL/d～2000mL/d，100mL/h～150mL/h. 利用重力或输注泵匀速滴注. 不足之液体与能量由外周静脉补给.
      TPN组经外周静脉进行，由500g/L葡萄糖及300g/L Intralipid分别提供约55%和45%的非蛋白热量，氮源为70g/L Vamin，多种维生素及微量元素，100g/L氯化钾30mL～40mL，胰岛素按1U∶5g～6g葡萄糖给予，混合于3L输液袋，约18h内均匀输入，共7d.
      EN组中任择6例，TPN组中任择4例，分别于术前、术后8d通过纤维结肠镜留取距离肛门15cm左右处肠粘膜标本，分别以100mL/L福尔马林、50mL/L戊二醛固定，以供镜检. 实验设计经医院伦理委员会核准，入组患者均签署知情同意书.
      监测内容：术前及术后8d测量三头肌皮褶厚度(TSF)，上臂周径(MAC)及体重，检测血清清蛋白(ALB)、转铁蛋白(TF)、前清蛋白(PAB)、肝功能、总淋巴细胞计数等，每日留24h尿测尿素氮，计算氮平衡：EN组氮平衡(g/d)＝氮摄入量-［尿尿素氮(g/d)+4］，TPN组氮平衡(g/d)＝氮摄入量-［尿尿素氮(g/d)+3］. 术后观察肠功能恢复时间，记录住院时间及费用. 甲醛固定的标本常规石蜡切片，HE染色，光镜观察，并测量粘膜层厚度、计数高倍视野下腺体数目［1］. 戊二醛固定的标本制成电镜标本，用EM400型透射电镜观察结肠粘膜超微结构.

     统计学处理  全部数据采用均数±标准差表示，并用自身配对和两样本均数t检验进行统计分析.

2  结果

EN组实际提供非蛋白热量(103.0±14.6)kJ/(kg·d)，氮(0.18±0.03)g/(kg·d)，非蛋白热量：氮=572.2kJ∶1g. TPN组实际提供非蛋白热量101kJ/(kg·d)±9kJ/(kg·d)，氮(0.10±0.02)g/(kg·d)，非蛋白热量：氮=983.6kJ∶1g. 体重、TSF、MAC两组术后数值均低于术前(P＜0.01)，组间比较无统计学差异(P＞0.05). 淋巴细胞计数、PAB两组营养支持前后无明显变化(P＞0.05)，ALB术后均降低(P＜0.01). TF在EN组无明显变化，但TPN组术后明显低于术前(P＜0.01，表1). 手术前后两组谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(AKP)组间比较无差异(P＞0.05). EN组前后AKP无显著变化(P＞0.05)，但TPN组术后增高明显(P＜0.05). 术后乳酸脱氢酶(LDH)TPN组高于EN组(P＜0.05). 总胆红素营养支持前后无显著改变(P＞0.05，表2). 两组术后均处于负氮平衡；术后7d累积氮平衡，EN组为-19g±16g，TPN组为-28g±12g，两组对比差异不显著(P＞0.05). 逐日累积氮平衡(CNB)见图1. EN前后结肠粘膜镜下改变不明显，基本保持了正常的组织结构. TPN组术后粘膜层变薄(P＜0.05)，肠腺排列疏松，单位腺体数目较前减少(P＜0.05). 两组组间比较无统计学差异(P＞0.05，表3，图2，3). EN前后结肠粘膜超微结构改变不明显，吸收细胞及表面微绒毛的分布、杯状细胞、内分泌细胞保持了正常的超微结构， 水分转运、胞饮及粘液分泌功能活跃，结缔组织中胶原纤维、成纤维细胞等无异常改变. TPN组术后标本显示细胞形态基本完整，细胞器结构基本正常，但微绒毛相对稀疏、变短，细胞器发达程度欠佳，粘液分泌及胞饮转运略差，结缔组织中巨噬细胞较多，胶原纤维较少(图4，5).

表1  血清蛋白、淋巴细胞计数的变化(x±s)

参    数 术    前 术    后
Lym (109/L)  EN 1.7±1.0 1.4±0.6
                  TPN 1.5±0.6 1.3±0.5
Alb (g/L)       EN 42.7±4.9  35.7±3.0b
                  TPN 39.9±4.6 33.8±5.1b
PAB (mg/L)   EN 190.7±57.9 175.7±55.9
                  TPN 193.6±80.2 178.8±69.7
TF (g/L)        EN 2.8±1.4 2.9±0.7
                  TPN 3.4±1.6 2.3±1.1b

bP＜0.01，vs