不同脂肪乳在肠外营养液中稳定性的研究

目的观察肠外营养液配制后在不同存放温度条件下脂肪乳的稳定性。方法采用规范化肠外营养液配制, 共配制24袋肠外营养液, 随机分为两组, A组12袋配方中脂肪乳为20%中/长链脂肪乳注射液(C6-24), B组12袋配方中脂肪乳为20%中/长链脂肪乳注射液(C8-24), 检测时间点为配制完成后24、48、72 h, 观察两组在2～8℃, 23～25℃和35～37℃中外观、营养液pH值和脂质过氧化。结果两组在4℃、25℃和36℃条件下分别放置24、48、72 h后, 外观均无明显变化, pH值差异无统计学意义(P>0.05), 脂质过氧化差异无统计学意义(P>0.05)。结论两种脂肪乳在不同存放条件下pH值、脂肪颗粒大小、脂质过氧化产物方面都较为稳定, 能够为进行静脉营养支持患者提供营养物质需求。     

"全合一"静脉营养液中电解质对脂肪乳稳定性的影响

"全合一"静脉营养液在临床上普遍使用,事实证明它是很安全和非常方便的.但脂肪乳剂在"全合一"静脉营养液中的稳定性问题始终让人担忧.由于病人的治疗需要,我们常常往"全合一"静脉营养液中加入一定量钾、钠、氯等一价离子,有些病人还需要补充钙、镁等二价离子.人们已从生物物理学上知道,这些电解质对脂肪乳剂的稳定性是有影响的 .输入颗粒较大的脂肪乳滴有可能栓塞毛细血管,但临床医师对此并没有给予足够的重视. 近期,我们对我院使用的"全合一"静脉营养液用光学显微镜对脂肪乳滴大小进行了观察, 终于了解到一些电解质对脂肪乳稳定性的影响,现报告如下:     

不同葡萄糖浓度全合一营养液体外稳定性评估

目的 评估不同时间点添加不同葡萄糖浓度全合一营养液的稳定性,为提高临床应用的安全性提供可靠依据.方法 根据临床应用情况,设计5组不同配方静脉营养液,其中葡萄糖终浓度分别为5％、10％、15％、20％和25％,其他营养素浓度每组相同.配制后的营养液于室温下（25±2）℃储存,分别在0、12、24、48、72 h时观察营养液外观变化,应用扫描电镜测量脂肪颗粒大小,并行营养液渗透浓度和pH值测定.结果 （1）肉眼观察各组营养液配制后0、12、24、48、72 h无颜色变化,未观察到沉淀、分层现象.（2）每组全合一营养液在不同时间点脂肪颗粒平均粒径值差异无统计学意义（F组内=1.255,P=0.324; F组间 =0.025,P=0.998; F交互=1.005,P=0.489）.72 h内,各组脂肪颗粒平均直径均＜0.5 μm,各组均未见到直径＞5.0 μm的脂肪颗粒.（3） 72 h内,所有营养液pH值波动于6.08 ±0.00～6.37±0.01之间.不同时间点5组营养液间pH值比较差异有统计学意义（F组内=3 452.846,P=0.000; F组间=4 655.250,P=0.000; F交互=1.952,P=0.079）.（4） 72 h内,所有营养液平均渗透浓度波动于（609.3±2.3）～（1 625.2±3.5） mOsm/L之间.不同时间点5组营养液间平均渗透浓度比较差异有统计学意义（F组内=176 195.911,P=0.000; F组间=14.732,P=0.006; F交互 =1.203,P=0.343）.结论 全合一营养液中葡萄糖终浓度为5％ ～ 15％时,脂肪颗粒、pH值和渗透压均在安全范围内.     

不同存放方式对肠外营养液稳定性影响的研究

目的:研究不同存放方式对全肠外营养(TPN)液稳定性的影响。方法:将两种配方的药物注入一次性肠外营养(PN)输液袋内配置成TPN液,分别在4℃、20~25℃和37℃三种条件下存放。放置于4℃条件下的营养液于0、1、2、3和5 d后取样,放置于20~25℃和37℃条件下的营养液于0、1、2和3 d后取样。观察外观性状,测定p H值、渗透浓度、脂肪颗粒直径和有无细菌生长等。结果:两种配方的全合一营养液在4℃、20~25℃和37℃三种条件下各观察期内肉眼上外观无明显变化、培养结果均无细菌生长,p H值、渗透浓度均在安全可用范围。放置4℃下的全合一营养液,在1和2 d内脂肪乳无直径1μm的脂肪颗粒。存放3和5 d后,脂肪颗粒平均直径仍在安全范围内,但有超过10%1μm,且大于存放0 d(P0.05)。放置于20~25℃、37℃下的全合一营养液,1 d脂肪颗粒直径在安全范围内。存放2、3 d仍在安全范围,但明显0 d(P0.05)。脂肪颗粒直径1μm的超过10%。结论:使用一次性PN输液袋配制的TPN液,在4℃保存2 d,22~25℃和37℃保存1 d的稳定性均较好。     

不同氨基酸浓度对新生儿肠外营养液稳定性的影响

目的　探讨不同氨基酸终浓度对新生儿肠外营养液稳定性的影响。方法　设计5组不同氨基酸终浓度（分别为0、1%、2%、3%和3.5%）的新生儿肠外营养液，每组各3袋，在配制后0、12、24、48、72 h时进行外观考察，测定pH值和渗透压，应用激光纳米粒度仪检测脂肪乳粒径大小和粒度分布。结果　5组肠外营养液在配制后0、12、24、48、72 h时肉眼观察外观颜色无变化，无分层、沉淀、絮凝、挂壁现象。在72 h内，5组肠外营养液pH值波动于（5.49±0.01）～（6.19±0.01），渗透压波动于（774±3）～（1 106±13）mOsm/kg，平均粒径大小波动于（280.6±0.7）～（332.2±2.0）nm，多分散指数值波动于（0.200±0.011）～（0.245±0.012）。随着氨基酸浓度的增高，5组肠外营养液的pH值逐渐下降（P=0.000），渗透压值逐渐升高（P=0.000），平均粒径大小逐渐增大（P=0.000），多分散指数值未呈现线性变化趋势（P=0.628）。结论　在室温下72 h内，未添加氨基酸或氨基酸终浓度≤3.5%时，新生儿肠外营养液的外观、pH值、渗透压和脂肪乳粒径大小均在安全范围内。     

蔗糖铁及右旋糖酐铁对儿科静脉营养液中脂肪乳剂稳定性的影响

目的 分析静脉营养液中分别加入两种不同铁剂（蔗糖铁及右旋糖酐铁）后对脂肪乳剂稳定性的影响。方法 按静脉营养配制操作规范加入两种不同剂量铁剂（分别为蔗糖铁及右旋糖酐铁）的静脉营养液各10袋,肉眼观察含不同当量铁剂（0.25、0.50、0.75和1.00 mg ）的静脉营养液在室温（25 ℃）悬挂静置3 d,扫描电镜观察3 d内的脂肪颗粒平均大小、直径＞0.5 μm百分比、营养混合液的pH值及渗透浓度。结果 含不同铁剂的营养液在不同时间点的脂肪颗粒大小差异无统计学性意义（F=0.32,P=0.7836;F=1.73,P=0.1321）。72 h内各组脂肪乳颗粒平均大小均＜0.5 μm,并且均未见到直径＞5 μm的脂肪颗粒,含不同浓度铁的TNA在不同时间点间脂肪颗粒＞0.5 μm的百分比、pH值及渗透压差异均无统计学意义 （百分比：F=1.47,P=0.3467;F=1.04,P=0.4758。pH值：F=0.63,P=0.5942;F=0.46,P=0.6825。渗透压：F=1.37,P=0.3648;F=0.65,P=0.6023）。结论 浓度小于1%蔗糖铁及右旋糖酐铁分别加入儿科静脉营养液是稳定的。     

全自动配液仪对营养液中脂肪乳剂稳定性影响的研究

目的:观察全自动配液仪及重力滴注法配制营养液中脂肪乳剂在不同储存条件下的稳定性.方法:运用全自动配液仪和重力滴注法,各配制10袋相同配方营养液,观察两组配制时间差异及3 L袋在25℃静置1 d时和4℃静置7 d、恢复25℃静置1 d时扫描电镜下脂肪颗粒平均大小、直径＞0.5 μm百分比、营养液pH值及渗透浓度.结果:全自动配液仪组配制时间明显小于重力滴注组;第1 d时,全自动配液仪组脂肪颗粒小于重力滴注组;全自动配液仪组营养液在4℃中静置7 d、恢复25℃静置1 d后,脂肪颗粒平均大小、直径＞0.5 μm的百分比以及营养液pH值、渗透浓度均在安全范围之内.结论:全自动配液仪更省时,即时配制的营养液稳定性和相容性均优于重力滴注法.     

谷氨酰胺的代谢及在肠外营养液中应用的进展

谷氨酰胺（Gln)是机体内量丰富的非必需氨基酸。近年来,对Gln的代谢、免疫功能的调节作用以及在肠外营养中的应用等方面做了大量的研究。本文对Gln的代谢、对肠道免疫功能的影响、在肠外营养液中的应用,以及丙氨酰-谷氨酰胺二肽的应用等方面作一综述。     

两种中/长链脂肪乳注射液在全合一(All-in-One)营养液中的稳定性对比研究

目的研究中伥链脂肪乳注射液在全合一(All—in-One)营养液中乳粒的大小及其分布的稳定性。方法本研究采用国产的中／长链脂肪乳注射液与已进口上市的MCT／LCT脂肪乳注射液比较,分别按照相同的处方配制成全合一营养液,各自静置在25℃1天后,存放于4℃8天,再25℃静置1天,随着不同的存放条件分别在第1、2、10天取样。用光散射分光光度法和库尔特微粒测定法测定营养液中的乳粒,观察乳粒大小及其分布的变化情况。同时测定样品的pH值和渗透压,观察营养液的稳定性以及营养液体系质点数的变化情况。结果在观察期内本研究的中／长链脂肪乳注射液与进口的MCT/LCT脂肪乳注射液在全营养液中比较,其乳粒大小及分布、pH值、渗透压变化均无显差别。结论本研究的中／长链脂肪乳注射液与进口上市的MCT／LCT脂肪乳注射液在全合一(All—in—One)营养液中具有相同的稳定性。     

丙氨酰-谷氨酰胺在有创机械通气时防治肠功能衰竭的作用

目的探讨有创机械通气患者使用丙氨酰-谷氨酰胺对防治其肠功能衰竭的作用。方法将人住呼吸加强医疗病房（RCU）使用有创机械通气的70例患者，随机分为丙氨酰-谷氨酰胺治疗组（A组）和无丙氨酰-谷氨酰胺治疗组（B组）。两组的基础治疗相同，包括有创机械通气、抗感染、营养支持、对症治疗及糖皮质激素应用等。A组加用丙氨酰-谷氨酰胺100ml（含丙氨酰8．20g，谷氨酰胺13．46g），每日1次静脉滴注，连续使用9d。治疗前和治疗后分别对两组患者进行肠功能评分。结果56例完成了临床研究，A组27例，B组29例。治疗后两组肠功能评分比较，差异有统计学意义（P〈0．05）。结论静脉使用丙氨酰-谷氨酰胺能够有效防治有创机械通气的危重症患者肠功能衰竭的发生。     

Administration of fat emulsions with nutritional mixtures from the 3-liter delivery system in total parenteral nutrition

A series of studies was performed to test the efficacy and safety of a parenteral lipid emulsion, Lipofundin S, when given as part of a complete nutritive mixture from the three-liter bag total parenteral nutrition (TPN) delivery system. In vitro stability studies with mixtures corresponding to high and low nutritional intakes showed the fat emulsion to be stable during refrigerated storage for at least 6 days. The clinical use of Lipofundin S in 3-liter TPN bags was studied in 39 consecutive patients requiring TPN, and there were no untoward side-effects. Nitrogen balance was maintained in patients with pancreatitis, those recovering postoperatively, and those with miscellaneous conditions. However, patients with multiple trauma remained in negative balance. The ability of sera, from patients on TPN to agglutinate Lipofundin S was compared to that from healthy controls, and acutely ill patients not on TPN. Patients on TPN showed a higher degree of in vitro creaming than acutely ill controls, and this may have been related to the severity of the underlying illness. These studies suggest that this parenteral lipid emulsion can be safely administered to patients requiring TPN when given from the 3-liter bag delivery system.     

Alteration of erythrocyte lipid composition following total parenteral nutrition in the rat

Rats were infused continuously for 7 days with a complete total parenteral nutrition (TPN) solution in which 27.5% total calories were given as a parenteral lipid emulsion containing soybean oil (Liposyn) or safflower oil (Intralipid) emulsified with egg phospholipid (PL). Compared to sham-operated rats fed chow, the erythrocyte membranes from rats given TPN with lipid emulsion had increased cholesterol and PL but normal molar cholesterol:PL ratios. The fatty acid changes in sphingomyelin and phosphatidylcholine, in particular, suggested replacement of endogenous PL with the exogenous egg PL infused with the emulsion. The changes in membrane lipid composition were accompanied by greater resistance of the cells from rats given TPN to osmotic lysis in vitro.     

Acid load during total parenteral nutrition: comparison of hydrochloric acid and acetic acid on plasma acid-base balance

The effects of hydrochloric acid and acetic acid on the plasma acid-base balance were investigated in four rabbits receiving parenteral nutrition. Hyperchloremic metabolic acidosis was observed only in the animals receiving total parenteral nutrition (TPN) whose pH was adjusted with hydrochloric acid. The observed acidosis was due to an excess of hydrogen ions with chloride ions as judged by the plasma-base excess and urinary net-acid excess and not by the infusion of solution having a high titratable acidity. The hydrogen ion released from the acetic acid added to TPN is consumed by the metabolism of the acetate ion and thus does not contribute to the net hydrogen-ion load. A reduction in the chloride load by using acetic acid to adjust the pH of the TPN solution when it is formulated can be safely achieved and prevents acidosis.     

Short-term TPN containing n-3 fatty acids ameliorate lactic acidosis induced by endotoxin in guinea pigs

We evaluated the effect of total parenteral nutrition (TPN) enriched with n-3 fatty acids on the physiologic response to endotoxin in guinea pigs. Animals were randomly assigned to receive TPN differing only in lipid source for 3.5 d. Group 1 received soybean fat emulsion (Intralipid) whereas group 2 received fish (menhaden) oil. During the last 7 h of TPN, animals were further randomized to have either saline or E coli endotoxin added to the infusate. Acid-base status and serum lactate concentrations were determined. Animals infused with soybean fat emulsions and endotoxin developed a significant metabolic acidosis, lactic acidemia, and decrease in mixed venous O2 compared with controls and fish-oil-treated animals (p less than 0.05). The significantly reduced serum lactate and higher mixed venous O2 in fish-oil-infused animals suggests that the underlying mechanism involves improvement in endotoxin-induced tissue hypoperfusion, presumably through alterations in prostaglandin metabolism.     

Internal biliary drainage, parenteral nutrition, and variation in the total parenteral nutrition feeding solutions: influence on the healing of colon anastomosis in jaundiced rats

The influence of preoperative internal biliary drainage and various types of total parenteral nutrition (TPN) on the healing of a colon anastomosis in 50 jaundiced rats was investigated. Jaundice was induced by division and ligation of the common bile duct. After 5 days a colon anastomosis was made. Ten days thereafter the bursting pressure of the anastomosis was measured as an assessment of wound healing. Bursting pressures were significantly lower in jaundiced rats compared with a sham-operated nonjaundiced group. Preoperative internal biliary drainage significantly improved bursting pressure (p less than 0.001) as did preoperative TPN (p less than 0.001). In the second part of the study the influence of four different feeding solutions on the healing of a colon anastomosis was tested. Solutions with and without 20% fat emulsion and a solution with branched-chain amino acids were tested as well as glucose only. No significant differences were observed among these four groups on the parameters tested.     

Significance of administration of fat emulsion: hepatic changes in infant rats receiving total parenteral nutrition with and without fat

Total parenteral nutrition (TPN) is associated with cholestasis and hepatic steatosis, which can be lethal in infants who cannot be fed orally. The present animal study focused on the metabolic complications in the liver that may occur due to the excessive administration of fat-free TPN. Thirty infant (3-week-old) male SD rats weighing 60-70 g were randomly allocated to five groups (n = 6): the OD group received an oral diet, the FT group received an oral diet and was fasted overnight on the last day of experiment before sacrifice, the 0% fat group received TPN without fat, the 20% fat group received TPN with 20% of calories from fat emulsion, and the 40% fat group received TPN with 40% of calories from fat emulsion. All TPN regimens were isocaloric, isonitrogenic, and administered for 4 days. In the 0% fat group, plasma levels of liver enzymes were significantly higher than in the other groups. Pathological examination showed hepatomegaly and severe fatty changes without cholestasis in the 0% fat group. The results of this study in infant rats indicate the importance of including fat in the TPN regimen in order to prevent the abnormal hepatic changes associated with the excessive administration of fat-free TPN.     

MCT/LCT emulsion ameliorate liver fat deposition in insulin-treated diabetic rats receiving total parenteral nutrition

This study was designed to investigate the effects of high energy infusion and insulin treatment on plasma and liver lipids in diabetic rats receiving total parenteral nutrition (TPN). Diabetes was induced in rats by streptozotocin. The diabetic rats were assigned to two TPN groups to receive either long chain triglyceride (LCT) or medium chain triglyceride (MCT)/LCT (1:1) as a fat source. The TPN solutions were isonitrogenous, isocaloric and identical in nutrient composition except for the fat emulsion. All rats received the TPN solution at an energy level of 35|kcal/100|g of body weight. The LCT and MCT/LCT groups were further divided into two subgroups, depending on whether they were treated with insulin. The results demonstrated that, between the MCT/LCT and LCT groups, no differences were observed in body weight and nitrogen retention, as well as the concentrations of plasma glucose, nonesterified fatty acids, beta-hydroxybutyrate, and total cholesterol. Diabetic TPN rats without insulin treatment had weight loss and negative nitrogen balance during the experiment. Diabetic TPN rats treated with insulin, however, demonstrated less weight loss and positive nitrogen retention. Insulin treated groups had significantly higher liver fat content than did those without insulin treatment. Furthermore, liver fat content was significantly higher in the LCT group than in the MCT/LCT group among insulin treated TPN rats. These results suggest that compared with the LCT emulsion, infusion of the MCT/LCT emulsion ameliorated liver fat deposition in insulin-treated diabetic rats receiving TPN.     

Hematologic disorders following prolonged use of intravenous fat emulsions in children

Abnormalities in hematologic parameters, associated with prolonged utilization of intravenous fat emulsion (IVFE), were observed in seven children on long-term cyclic total parenteral nutrition (TPN). All patients were receiving IVFE (Intralipid 20%) 1 to 2 g/kg/24 hr as part of TPN, during 3 to 18 months. Recurrent thrombocytopenia occurred in all seven patients. Platelet lifespan, as measured with 111 Indium was reduced. Sea-blue histiocytes containing granulations and hemophagocytosis were seen on bone marrow smears. Scans taken after injection of autologous erythrocytes labeled with technetium-99 showed bone marrow sequestration of these cells. Taken together, this constellation of hematologic abnormalities suggests that long-term IVFE administration induces hyperactivation of the monocyte-macrophage system.