Formulation of enteral diets.

The number of enteral diets has increased from a handful in the 1970s to over 100 at present. These can be classified as polymeric, chemically defined, disease-specific, and specialized diets, as well as oral dietary supplements. The properties, indications, pros and cons for the use of these diets are outlined in an effort to assist clinicians in their selection.     

内镜下放置鼻空肠营养管的方法和营养效果分析

目的:探讨分析内镜下放置空肠营养管的方法和营养支持效果。方法:选择106例需放置空肠营养管的病人随机分为观察组54例和对照组52例。此外,选择同期行鼻胃管肠内营养病人43例作为鼻胃管组。对照组采用传统内镜下经鼻空肠营养管置管术;观察组采用改良后内镜下经鼻空肠营养管置管术;鼻胃管组采取常规鼻胃管肠内营养。比较三组病人手术时间、一次性置管成功率、置管后并发症发生率以及病人置管后营养指标变化情况。结果:观察组和鼻胃管组病人手术时间显著短于对照组(P0.05),一次性置管成功率显著高于对照组(P0.05)。三组病人置管后并发症发生率无显著性差异(P0.05)。三组病人置管后血红蛋白、血清清蛋白以及前清蛋白水平均较治疗前显著改善(P0.05)。观察组和对照组病人置管前后营养指标比较均无显著性差异(P0.05),而鼻胃管组病人置管后血红蛋白、血清清蛋白和前清蛋白水平显著低于观察组和对照组(P0.05)。结论:改良内镜下鼻空肠管置管术能有效缩短置管手术时间,提高一次性置管成功率,降低病人置管手术的痛苦。置管后病人营养支持效果显著。     

Conversion of choledochojejunostomy stents to jejunal feeding tubes for postoperative enteral alimentation

The problem of protein calorie malnutrition following major gastrointestinal surgery can be treated with central venous or enteric alimentation, with the latter being preferred. The authors describe a simple technique for the conversion of biliary stents placed after pancreaticoduodenal surgery into jejunal feeding tubes when the stenting function is no longer needed. Three illustrative cases are presented. In each case, the procedure took less than 30 min and had no associated morbidity. This technique allows early conversion from central venous to enteric alimentation without the need to create a second surgical enterostomy.     

A kit for conducting enteral feeding

A new kit for probe feeding permits to provide dosaged and continuous administration of nutritional mixtures with a certain speed and intervals. The complex is supplied with a device that permits to maintain a certain temperature of the mixture (if necessary the range of heating and cooling varies from 10 to 40 degrees C) and an electromixer, that prevents the mixture viscosity increase. The kit is successfully used for enteral (probe) feeding in patients with acute purulent infection and sepsis.     

New lipids in enteral feeding

PURPOSE OF REVIEW: Lipid sources for enteral nutrition continue to be an exciting area of investigation. It is timely to review recent developments which have largely contributed to thrust enteral feeding into a new era. RECENT FINDINGS: Although much more research needs to be done, there is a better understanding of the competitive relationships between n-6/n-3 fatty acids in conditions of metabolic and immune stress as well as in autoimmune and degenerative diseases. Although structured lipids are more completely absorbed and cleared, other more important clinical benefits need to be documented before they can be considered cost-effective. Immune enhancing formulas are the subject of controversy and some have been shown to be more effective than others. Enteral formulations with short-chain fatty acids are promising but more experimental work on the normal, and the sick colon is needed. Finally, there are a few isolated studies suggesting that enteral feeding with liposomes and with lipolytic products may have advantages when the digestive phase needs to be circumvented. The era of nutrigenomics, in which the effect of specific lipids on genes and proteins is being explored, is with us. We can look forward to nutrigenetics when the effect of genetic variation on the interaction between diet and disease will guide our practice. SUMMARY: Clinicians already have access to lipid sources and formulations which allow them to individualize enteral feeding programs. More clinical and technological research needs to be carried out, however, before products can be tailored to produce optimal effects in specific conditions.     

Gastroparesis and jejunal feeding.

A kidney transplant patient with diabetic gastroparesis was effectively treated by jejunal feeding. The patient, a 31-year-old woman, has a complicated medical history, with insulin-dependent diabetes mellitus. Complications include kidney failure followed by transplantation, bilateral knee amputations, and being registered blind. She was admitted with nausea and vomiting for the previous 6 days; the provisional diagnosis was diabetic gastroparesis. Various treatments were tried, including several prokinetic drugs and total parenteral nutrition. The total parenteral nutrition provided most of the patient's nutritional requirements, and, only slight weight loss was observed. Nothing seemed to improve the symptoms of vomiting. An endoscopic retrograde cholangiopancreatography, a radiographic examination of the bile and pancreatic ducts, was performed to exclude obstruction. At the same time, having found nothing, a gastrostomy was placed with a jejunal extension. Feeding was established within 3 days. Her weight remained stable after 7 weeks of jejunal feeding. She had started to increase her oral intake of solid foods and fluids. By 8 weeks, she was taking a full oral diet and fluids. Now, 14 weeks after the placement of the gastrostomy tube with the jejunal extension, she is doing well. Her weight remains stable and her oral intake is excellent. Her diabetes is under control. After 22 weeks, the gastrostomy was removed. After this success with jejunal feeding when all other treatments had failed, this treatment could be used to treat future diabetic gastroparesis. Slow introduction of the feed seems to help toleration.     

建立一种简易的大鼠肠内营养支持模型

目的:研究和建立一种简易可靠的EN支持大鼠模型。方法:将32只大鼠剖腹建立急性胰腺炎模型,术中经胃放置EN管至Treitz韧带以下5 cm。在导管入口处、胃体、腹膜、颈背部和尾部5处缝合固定导管,用一次性静脉输液管与营养管连接,调节输液管上滑轮,连续匀速输注EN液。结果:所有大鼠均置管成功,平均输液时间为7 d,均耐受良好,无腹泻等症状。TEN支持3～4 d后开始获得正氮平衡。导管无脱出、折曲和泄漏等。结论:该EN支持模型简易、牢固、可靠,所用器材价廉易得,可同时大规模进行,能满足小动物EN支持研究的需求。     

Clinical indications for weighted enteral feeding tubes

Simple unweighted fine bore feeding tubes have been used by our Nutritional Support Team for routine nasogastric feeding with success in large numbers of patients. Three clinical situations where mercury or tungsten weighted tubes offer advantages over fine bore tubes have been defined. Significant advantages in patients with concurrent endotracheal intubation, gastric atony and severe oesophageal stricturing are described.     

平衡肠内营养制剂在外科中的应用

12例腹部大手术后病人,年龄16～70岁,应用标准的平衡管饲膳行肠内喂养。持续7天。使用Nutrison2～3天后,剂量维持在每天蛋白质808,非蛋白热卡1680卡。应用前后营养及人体测量参数表明肠内喂养可使机体维持营养状态稳定,改善负氮平衡,对血液和肝肾功能无明显影响,消化道副反应轻。     

Modification of enteral diets in inflammatory bowel disease

The provision of food is thought to promote the maintenance of gut integrity. Nutrients are able to elicit and affect both systemic and mucosal immune responses. Enteral diet therapy has long been known to be efficacious in inflammatory bowel disease (IBD), particularly in childhood Crohn's disease. However, the mechanisms of action of these diets are not clear. Nutritional repletion, direct effects on the gut mucosa or decreased intestinal permeability have all been postulated as being important in nutritional therapy. There is some evidence that the enteral diet has a direct effect on the gut mucosa by reducing cytokine production and the accompanying inflammation, thus leading to decreased intestinal permeability. Modifications of enteral diet composition have been evaluated in many studies. Such modifications include fat and/or protein content and the addition of bioactive peptides. The fatty acid composition of the enteral diet seems to have a much greater impact on its efficacy than modification of the N source. As specific fatty acids are precursors of inflammatory mediators derived from arachidonic acid, the reduction in these components may be beneficial in nutritional therapy for IBD. Addition of bioactive peptides to enteral diet formulas may also have a role; such peptides may have specific growth factor or anti-inflammatory actions. There is still much work to be done to define disease-specific enteral diet formulas that are effective as therapies for both Crohn's disease and ulcerative colitis.     

Hyperkalemia in patients on enteral feeding

The amount of potassium (K) in proprietary enteral feeds varies considerably from 2.7-9.2 mmol K+/g N. It has been suggested that up to 7 mmol K+/g N is required by the anabolic patient. The aim of this study was to determine the effect of a proprietary feed (Triosorbon MCT), containing 6.9 mmol K+/g N, on serum and urinary K in 13 patients requiring nutritional support. Serum electrolytes in all patients and urinary electrolytes in 7 were measured both before feeding commenced and when they had achieved an intake of between 2.4 and 3.0 liter/day (102-127 mmol K+/day) of full strength feed for a period of 1 wk. Ther serum K rose in all patients from 4.2 +/- 0.5 mmol/liter (mean +/- SD) before feeding to 5.1 +/- 0.5 after feeding for 1 wk (p less than 0.001; pair-difference t-test). The daily urinary K excretion rose from 37.8 +/- 24.2 mmol/day to 61.8 +/- 26.6 over the same period (p less than 0.001) The serum urea rose from 4.7 +/- 2.0 mmol/liter to 6.3 +/- 3.2 (p less than 0.05). No significant change was observed in other serum electrolytes, creatinine, or urinary electrolytes. During the whole course of feeding (range 1-11 wk) it was necessary to discontinue Triosorbon in 2 patients whose serum K concentration became elevated to greater than 6 mmol/liter. We conclude that the recommended levels of K intake may be too high and that serum K should be carefully monitored during enteral feeding.     

A technique for enteral feeding in unrestrained chronic dogs

A new apparatus for the continuous infusion-feeding of unrestrained dogs is described. The swivel we designed, like the whole apparatus, is quite simple but has proven to be totally effective inasmuch as it needs no day-to-day care. The system has been satisfactorily used for jejunal feeding for periods of up to 33 days. Dogs were very easily acclimatized to this apparatus; the majority of animals lost weight at the beginning of enteral feeding but recovered their body weight after 19 days if a daily caloric intake fixed at a minimum of 100 kcal/kg body weight was provided. The mechanical complications secondary to catheterization of the gastrointestinal tract can be abolished by anchoring the vinyl tube to the intestinal wall. The dog appeared to be an excellent species for long-term experiments as little attention was required during the infusion period; because general adaptation to Isocal was good, feeding hypercaloric amounts of diet was unnecessary to sustain adequate body weight. This model was found to be well suited for the surgical and feeding techniques required for a long-term study of enteral nutrition.     

Effect of jejunal long-term feeding in chronic pancreatitis

BACKGROUND: In the late course of chronic pancreatitis (CP), weight loss is often seen because of reduced caloric intake and a reduction of pancreatic enzyme secretion, resulting in maldigestion. Most of these patients can be managed by dietary recommendations and pancreatic enzyme supplementation. However, approximately 5% of these patients are reported to be candidates for enteral nutrition support during their course of CP. Although small bowel access for enteral feeding can be easily obtained by percutaneous endoscopic gastrojejunostomy (PEG/J) or direct percutaneous endoscopic jejunostomy (DPEJ), to date there are no data regarding clinical outcome and safety of long-term jejunal feeding in CP. METHODS: From January 1999 to October 2002, 57 patients receiving enteral nutrition by PEG/J or DPEJ were retrospectively analyzed during a follow-up period of 6 months. There were 38 females and 19 males, with an average age of 46.6 years. RESULTS: Small-bowel access was obtained by PEG/J in 53 patients and by DPEJ in 4. Duration of enteral feeding was 113 days. Average body weight significantly increased from 64.8 kg at day 1 to 69.1 kg at day 180 (p < .001). The percentage of patients with abdominal pain decreased from 96% to 23%. One patient sustained a colon mesentery injury after DPEJ tube placement. CONCLUSIONS: Long-term nutrition support by PEG/J or DPEJ in patients with symptomatic, chronic pancreatitis increases patients' body weight and decreases the degree of malnutrition, abdominal pain, and other gastrointestinal symptoms. The underlying mechanisms for these observations are unclear and require further investigation. Small-bowel rest with reduced pancreatic gland stimulation might be a key component. Moderately to severely malnourished patients who do not respond to oral dietary interventions and who are candidates for elective pancreatic surgery might also be candidates for long-term preoperative jejunal feeding to reduce malnutrition-associated perioperative complications. In experienced hands, we feel that long-term jejunal feeding is safe, with minimal major complications.