Calcium and phosphorus metabolism during total parenteral nutrition.

Calcium and phosphorus metabolism and balance were studied in 151 patients receiving total parenteral nutrition (TPN). Hypercalciuria was common, with mean (+/- SD) urinary calcium excretion 17.5 +/- 3.9 meq/24 hours (n = 2610). There was a significant positive correlation between urinary calcium excretion and parenteral calcium intake (r = 0.34, p less than 0.001). There was also a positive correlation between calcium balance and parenteral calcium intake (r = 0.61, p less than 0.001) in patients without extra-renal losses. Positive calcium balance was achieved with parenteral calcium intake greater than 15 meq/24 hours. Urinary phosphorus excretion correlated positively with parenteral phosphorus intake (r = 0.50, p less than 0.001). Phosphorous balance also correlated positively with parenteral phosphorus intake (r = 0.78, p less than 0.001). Positive phosphorus balance was achieved with parenteral phosphorus intake above 15 mmol/24 hours. Fifty-three patients received 1,000 IU vitamin D once weekly and showed no significant change in serum calcium. Ninety-eight patients received 1,000 IU vitamin D twice weekly and showed a gradual but significant mean increase over time in serum calcium.     

Effect of difluoromethylornithine on host and tumor polyamine metabolism during total parenteral nutrition

Clinical and experimental data suggest that erythrocyte (RBC) polyamine (PA) levels are markers of tumor proliferation during total parenteral nutrition (TPN). The purpose of this experiment was to determine whether the inhibition of PA synthesis during TPN was greater in tumors than in normal host tissue. Rats bearing a subcutaneous fibrosarcoma were randomized to receive a chow diet (n = 5), TPN (n = 5), or TPN + difluoromethylornithine (DFMO) (an irreversible inhibitor of ornithine decarboxylase (ODC), at 1000 mg/kg body wt/day n = 4) for 6 days by continuous central venous infusion. TPN + DFMO resulted in a higher plasma albumin level and lower tumor ODC activity compared with chow feeding or TPN. Liver ODC activity was similar for the chow fed, TPN, and TPN + DFMO groups. RBC putrescine, tumor putrescine, and tumor spermidine levels were significantly lower in the TPN + DFMO group compared with the chow fed and TPN groups. RBC spermidine, RBC spermine, and tumor spermine levels were significantly increased with TPN + DFMO compared with TPN alone. DFMO did not produce diarrhea or weight loss. Increased RBC spermidine may indicate a toxic effect of DFMO on the tumor, resulting in leakage of tumor spermidine into the extracellular space. The data suggest that DFMO during TPN can selectively inhibit tumor PA synthesis and may improve host utilization of nutrients.     

Medium-chain triglycerides metabolism and its application in total parenteral nutrition

Twenty patients undergoing uneventful gastrectomy were randomly assigned to receive TPN containing either 10% Intralipid or 10% Lipofundin (MCT/LCT) beginning postoperative day (POD) 1 through POD 6. Patients were given non-protein energy 27 kcal/kg/d and nitrogen 0.14 g/kg/d through peripheral vein along with fat emulsion. Body weight, hemoglobin, blood lymphocyte count, SGPT, serum bilirubin, AKP, BUN, Cr, serum albumin, transferrin, prealbumin, fibronectin, creatine phosphokinase, serum and plasma cholesterol, triglycerides, plasma free fatty acids, blood sugar, serum insulin, urinary creatinine and nitrogen balance were monitored. It was found that MCT-based fat emulsion was tolerated without any side effects. Kinetics study showed that levels of medium chain free fatty acids increased during MCT-based fat emulsion infusion, but returned to normal within 2 hours on cessation of infusion, indicating good clearance of MCT. Plasma concentration of triglycerides in the LCT group was higher than that in the MCT group at 2 hours after infusion. On POD 6, better nitrogen balance was observed in the MCT group, 0.44 +/- 0.21 g/d (-1.4 +/- 0.51 g/d in the LCT group). Urinary excretion of creatinine in the MCT group was also less than in the LCT group (0.76 +/- 0.03 g/d vs. 1.034 +/- 0.11 g/d). LCT was also observed to induce an elevation of serum bilirubin (1.12 +/- 0.11 mg/dl). These results indicate that MCT-based fat emulsion appears to be a safe energy source.     

重症急性胰腺炎完全胃肠外营养与肠外联合肠内营养治疗对比研究

目的 观察重症急性胰腺炎(SAP)完全胃肠外营养(TPN)与肠外营养(PN)联合肠内营养(EN)治疗中各项指标的变化,分析二者疗效.方法 29例SAP随机分为TPN组(14例)和PN+EN组(15例),并均行非手术治疗14 d,观察疗效及化验指标的变化.结果 营养支持治疗14 d后,各组血清白蛋白(ALB)、总蛋白(TSP)、血钙(Ca2+)、谷丙转氨酶(ALT)、谷草转氨酶(AST) 较营养支持前均显著升高(P<0.05);各组血糖、血清淀粉酶、血WBC均较营养支持前显著下降(P<0.05);各组血总胆红素(TB)治疗前后差异无统计学意义(P>0.05);PN+EN组血WBC显著低于TPN组(P<0.05),其余化验指标组间比较差异无统计学意义(P>0.05);各组APACHEⅡ评分较治疗前显著降低(P<0.05),PN+EN组评分显著低于TPN组(P<0.05).PN+EN组住院天数、住院总费用、感染发生率及死亡率均显著低于TPN组(P<0.05).结论 PN联合EN治疗SAP优于TPN.     

重症急性胰腺炎完全胃肠外营养与肠外联合肠内营养治疗对比研究

目的 观察重症急性胰腺炎(SAP)完全胃肠外营养(TPN)与肠外营养(PN)联合肠内营养(EN)治疗中各项指标的变化,分析二者疗效.方法 29例SAP随机分为TPN组(14例)和PN+EN组(15例),并均行非手术治疗14 d,观察疗效及化验指标的变化.结果 营养支持治疗14 d后,各组血清白蛋白(ALB)、总蛋白(TSP)、血钙(Ca2+)、谷丙转氨酶(ALT)、谷草转氨酶(AST) 较营养支持前均显著升高(P<0.05);各组血糖、血清淀粉酶、血WBC均较营养支持前显著下降(P<0.05);各组血总胆红素(TB)治疗前后差异无统计学意义(P>0.05);PN+EN组血WBC显著低于TPN组(P<0.05),其余化验指标组间比较差异无统计学意义(P>0.05);各组APACHEⅡ评分较治疗前显著降低(P<0.05),PN+EN组评分显著低于TPN组(P<0.05).PN+EN组住院天数、住院总费用、感染发生率及死亡率均显著低于TPN组(P<0.05).结论 PN联合EN治疗SAP优于TPN.     

Liver biochemical and histological changes with graded amounts of total parenteral nutrition

We sought to determine whether an excess in energy intake as total parenteral nutrition would result in liver biochemical and histological changes in the presence of a functional gastrointestinal tract. Three groups of rats were given amounts of total parenteral nutrition that provided either 25% (total parenteral nutrition-25), 100% (total parenteral nutrition-100), or 200% (total parenteral nutrition-200) of a rat's energy requirements. Rat chow and water were available ad libitum. Food intake decreased in proportion to the amount of total parenteral nutrition infused; it ceased with total parenteral nutrition-200. Liver glycogen and triglyceride concentrations were higher with high energy intake (total parenteral nutrition-100 and total parenteral nutrition-200), while total liver nitrogen concentrations remained unchanged. No cholestasis, inflammation, or fibrosis was seen histologically. Fatty vacuoles were increased with total parenteral nutrition (more so with total parenteral nutrition-200) but a prompt return to normal liver features was observed after cessation of total parenteral nutrition and the resumption of normal food intake.     

Hydrocephalus as a complication of jugular catheterization during total parenteral nutrition

In four children with communicating hydrocephalus the development of the hydrocephalus appears to be related to the use of bilateral jugular catheters inserted for total parenteral nutrition.     

Abnormalities of zinc and copper during total parenteral nutrition.

Changes in serum zinc and copper levels were studied in 19 tumor bearing patients undergoing parenteral nutrition (TPN) for five to 42 days. Before initiation of intravenous feeding mean serum zinc and copper concentrations were within normal limits but during TPN levels decreased significantly below those measured prior to parenteral nutrition. During TPN nitrogen, zinc, and copper intake, urinary output and serum levels were studied prospectively in nine of these patients. These nine patients exhibited positive nitrogen retention based upon urinary nitrogen excretion, but elevated urinary zinc and copper excretion and lowered serum zinc and copper concentrations. Neither blood administration nor limited oral intake was consistently able to maintain normal serum levels of zinc or copper. Zinc and copper supplementation of hyperalimentation fluids in four patients studied for five to 16 days was successful in increasing serum zinc and copper levels in only two. The data obtained suggest that patients undergoing parenteral nutrition may require supplementation of zinc and copper to prevent deficiencies of these elements.     

Zinc deficiency during total parenteral nutrition in childhood.

Changes in plasma zinc levels were studied in 11 pediatric surgical patients treated with total parenteral nutrition. Plasma copper levels were also determined in some patients. In three patients plasma zinc fell to a very low level during long-term total parenteral nutrition, and a syndrome of zinc deficiency developed characterized by dermatitis, alpecia, and enterocolitis with striking response to intravenous zinc therapy. In contrast, plasma zinc levels in the patients with short-term total parenteral nutrition remained in the normal range during the present study. This suggests that one of the mechanisms of zinc deficiency during total parenteral nutrition is insufficient amount of zinc in the nutritional solutions for long-term use, especially for older children. Symptoms of the zinc deficiency also occurred in these patients during the anabolic phase, suggesting that tissue demand for zinc may be increased at that time. Therefore, zinc should be included, on a regular basis, in all parenteral nutritional solutions in amounts sufficient to meet estimated needs for growth and tissue repair.     

Essential fatty acid deficiency during total parenteral nutrition.

Essential fatty acid (EFA) deficiency has become a clinical problem since the advent of fat-free total parenteral nutrition (TPN). The following study was done to determine the minimum fat requirements for patients receiving continuous TPN solution. Seventy-seven patients who had 97 courses of TPN of at least 14 days duration were prospectively studied. The following fat supplementation was given: a) none, b) 10% soybean oil emulsion intravenously at fixed dosage, c) fat from an oral diet, or d) intravenous and oral fat. No patient was EFA deficient before the onset of TPN. EFA deficiency was prevented when at least 3.2% of total calories were given as intravenous fat or at least 15% as oral fat. Lesser amounts of fat decreased the rate of EFA deficiency development but did not prevent it from occurring. The 7.7 g/day of linoleic acid provided in 1000 ml per week of 10% soybean oil emulsion provides adequate fat to prevent EFA deficiency.     

Immunorestorative effect of lipid emulsions during total parenteral nutrition

This prospective in vivo cross-over study investigated the effect of Intralipid on immune responses. Twenty-three patients were randomly allocated to receive one of two alternative total parenteral nutrition (TPN) regimens for the first 7 days and the other regimen for the second 7 days. Only one of the regimens included a fat emulsion to provide 50 per cent of the calorific requirement. Immunological studies were performed on days 0, 7 and 14. These included peripheral blood T cell subsets, antibody dependent cellular cytotoxicity and basal and maximal Interleukin 2 production. All immunological parameters were significantly augmented during total parenteral nutrition using the lipid based regimen. No such change was seen during intravenous feeding with carbohydrate based TPN. It is concluded that, far from being immunosuppressive, the incorporation of a fat emulsion into a TPN regimen has immunostimulatory properties.     

Nitrogen balance during total parenteral nutrition: glucose vs. fat.

Nitrogen balance and energy expenditure were measured in 18 traumatized and/or septic patients and five depleted patients during different dietary conditions. Total parenteral nutrition (TPN) was given with nonprotein energy entirely as hypertonic glucose solutions (glucose system) or as half glucose-half intravenous fat emulsion (lipid system). In acutely ill patients, the change from 5% dextrose to TPN resulted in a prompt improvement of nitrogen balance to maintenance levels. There were no significant differences between patients given the glucose or lipid system. The five depleted patients were given the lipid and glucose systems alternately for a total of 19 one-week periods. A highly positive N balance, 80 mg N/kg . day, was attained on both diets. There was no significant difference between diets and no period of adaptation after switching from one diet to the other. On comparable intravenous diets, the acutely ill patients had higher plasma concentrations of glucose, glycerol, triglycerides, insulin, and glucagon than did the depleted patients. The study shows that the nitrogen-sparing effects of the lipid and the glucose systems are similar in moderately traumatized or infected as well as in malnourished patients. Factors other than nitrogen balance are of greater importance when choosing between the lipid and the glucose system for intravenous support.