Enteral versus parenteral therapy for intractable diarrhea of infancy: a prospective, randomized trial

Leitsymptome und Differenzialdiagnostik

Die Vorstellung eines Kindes mit akuten Bauchschmerzen erfolgt meist kurz nach Schmerzbeginn, nicht selten nachts und zu Zeiten eingeschränkter Diagnostik. Erschwert ist die Diagnosefindung durch fehlende Verbalisierung der Schmerzen bei Kleinkindern und Säuglingen sowie durch vage und wenig präzise Angaben zu Schmerzcharakter und Lokalisation bei älteren Kindern.

Does enteral nutrition affect clinical outcome? A systematic review of the randomized trials

BACKGROUND

Both parenteral nutrition (PN) and enteral nutrition (EN) are widely advocated as adjunctive care in patients with various diseases. A systematic review of 82 randomized controlled trials (RCTs) of PN published in 2001 found little, if any, effect on mortality, morbidity, or duration of hospital stay; in some situations, PN increased infectious complication rates.

OBJECTIVE

The objective was to assess the effect of EN or volitional nutrition support (VNS) in individual disease states from available RCTs.

DESIGN

We conducted a systematic review. RCTs comparing EN or VNS with untreated controls, or comparing EN with PN, were identified and separated according to the underlying disease state. Meta-analysis was performed when at least three RCTs provided data. The evidence from the RCTs was summarized into one of five grades. A or B, respectively, indicated the presence of strong or weak (low-quality RCTs) evidence supporting the use of the intervention. C indicated a lack of adequate evidence to make any decision about efficacy. D indicated that limited data could not support the intervention. E indicated either that strong data found no effect, or that either strong or weak data suggested that the intervention caused harm.

PATIENTS AND SETTINGS

RCTs could include either hospitalized or nonhospitalized patients. The EN or VNS had to be provided as part of a treatment plan for an underlying disease process.

INTERVENTIONS

The RCT had to compare recipients of either EN or VNS with controls not receiving any type of artificial nutrition or had to compare recipients of EN with recipients of PN.

OUTCOME MEASURES

These were mortality, morbidity (disease specific), duration of hospitalization, cost, or interventional complications. SUMMARY OF GRADING: A: No indication was identified. B: EN or VNS in the perioperative patient or in patients with chronic liver disease; EN in critically ill patients or low birth weight infants (trophic feeding); VNS in malnourished geriatric patients. (The low-quality trials found a significant difference in survival favoring the VNS recipients in the malnourished geriatric patient trials; two high-quality trials found nonsignificant differences that favored VNS as well.) C: EN or VNS in liver transplantation, cystic fibrosis, renal failure, pediatric conditions other than low birth weight infants, well-nourished geriatric patients, nonstroke neurologic conditions, AIDS; EN in acute pancreatitis, chronic obstructive pulmonary disease, nonmalnourished geriatric patients; VNS in inflammatory bowel disease, arthritis, cardiac disease, pregnancy, allergic patients, preoperative bowel preparation. D: EN or VNS in patients receiving nonsurgical cancer treatment or in patients with hip fractures; EN in patients with inflammatory bowel disease; VNS in patients with chronic obstructive pulmonary disease. E: EN in the first week in dysphagic, or VNS at any time in nondysphagic, stroke patients who are not malnourished; dysphagia persisting for weeks will presumably ultimately require EN.

CONCLUSIONS

There is strong evidence for not using EN in the first week in dysphagic, and not using VNS at all in nondysphagic, stroke patients who are not malnourished. There is reasonable evidence for using VNS in malnourished geriatric patients. The recommendations to consider EN/VNS in perioperative/liver/critically ill/low birth weight patients are limited by the low quality of the RCTs. No evidence could be identified to justify the use of EN/VNS in other disease states.

Oral versus intravenous rehydration for treating dehydration due to gastroenteritis in children

BACKGROUND

Dehydration associated with gastroenteritis is a serious complication. Oral rehydration is an effective and inexpensive treatment, but some physicians prefer intravenous methods.

OBJECTIVES

To compare oral with intravenous therapy for treating dehydration due to acute gastroenteritis in children.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group Specialized Register (March 2006), CENTRAL (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to March 2006), EMBASE (1974 to March 2006), LILACS (1982 to March 2006), and reference lists. We also contacted researchers, pharmaceutical companies, and relevant organizations.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing intravenous rehydration therapy (IVT) with oral rehydration therapy (ORT) in children up to 18 years of age with acute gastroenteritis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed quality using the Jadad score. We expressed dichotomous data as a risk difference (RD) and number needed to treat (NNT), and continuous data as a weighted mean difference (WMD). We used meta-regression for subgroup analyses.

MAIN RESULTS

Seventeen trials (1811 participants), of poor to moderate quality, were included. There were more treatment failures with ORT (RD 4%, 95% confidence interval (CI) 1 to 7, random-effects model; 1811 participants, 18 trials; NNT = 25). Six deaths occurred in the IVT group and two in the ORT groups (4 trials). There were no significant differences in weight gain (369 participants, 6 trials), hyponatremia (248 participants, 2 trials) or hypernatremia (1062 participants, 10 trials), duration of diarrhea (960 participants, 8 trials), or total fluid intake at six hours (985 participants, 8 trials) and 24 hours (835 participants, 7 trials). Shorter hospital stays were reported for the ORT group (WMD -1.20 days, 95% CI -2.38 to -0.02 days; 526 participants, 6 trials). Phlebitis occurred more often in the IVT group (NNT 50, 95% CI 25 to 100) and paralytic ileus more often in the ORT group (NNT 33, 95% CI 20 to 100, fixed-effect model), but there was no significant difference between ORT using the low osmolarity solutions recommended by the World Health Organization and IVT (729 participants, 6 trials).

AUTHORS' CONCLUSIONS

Although no clinically important differences between ORT and IVT, the ORT group did have a higher risk of paralytic ileus, and the IVT group was exposed to risks of intravenous therapy. For every 25 children (95% CI 14 to 100) treated with ORT one would fail and require IVT.

Intestinal rehabilitation and the short bowel syndrome: part 1

The management of patients with intestinal failure due to short bowel syndrome (SBS) is complex, requiring a comprehensive approach that frequently necessitates long-term, if not life-long, use of parenteral nutrition (PN). Despite tremendous advances in the provision of PN over the past three decades, which have allowed significant improvements in the survival and quality of life of these patients, this mode of nutritional support carries with it significant risks to the patient, is very costly and, ultimately, does not attempt to improve the function of the remaining bowel. Intestinal rehabilitation refers to the process of restoring enteral autonomy and, thus, allowing freedom from parenteral nutrition, usually by means of dietary, medical, and, occasionally, surgical strategies. While recent investigations have focused on the use of trophic substances to increase the absorptive function of the remaining gut, whether intestinal rehabilitation occurs as a consequence of enhanced bowel adaptation or is simply a result of an optimized, comprehensive approach to the care of these patients remains unclear. In Part 1 of this review, an overview of SBS and pathophysiological considerations related to the remaining bowel anatomy in these patients will be provided. Additionally, a review of intestinal adaptation and factors that may enhance the adaptive process, focusing on evidence derived from animal studies, will also be discussed. In Part 2, relevant data on the development of intestinal adaptation in studies involving humans will be reviewed as will the general management of SBS. Lastly, the potential benefits of a multidisciplinary intestinal rehabilitation program in the care of these patients will also be discussed.

Changes in epithelial cell turnover and extracellular matrix in human small intestine after TPN

BACKGROUND

The atrophy and architectural remodeling of the jejunal mucosa arising in adults receiving total parenteral nutrition (TPN) has been suggested to originate from a disturbance in tissue homeostasis. The present study aims at examining (1) whether there are differences in proliferation and apoptosis of epithelial cells between enterally and parenterally nourished patients and (2) whether the distribution pattern of extracellular matrix (ECM) proteins known to influence cell turnover along the the crypt-villus axis is changed after TPN.

METHODS

The mitotic frequency and the proliferation index [using an antibody against Ki-67 antigen (MIB 1)] were determined on epoxy semithin and paraffin sections, respectively. Morphological techniques and the TUNEL assay were applied to detect apoptotic events. Immunolocalization of collagen IV, laminin, fibronectin, tenascin, and collagen VI was performed on cryosections.

RESULTS

After TPN the cell renewal was significantly enhanced, while epithelial cell death was drastically reduced. The comparison of TPN and EN patients revealed differences in the distribution patterns of the ECM proteins laminin, fibronectin, and tenascin along the crypt-villus axis. Moreover, after TPN an increased expression of collagen types IV and VI was observed.

CONCLUSIONS

TPN in human adults is associated with alterations in epithelial cell turnover and changes in expression and/or localization of ECM proteins. Thus, the inverted route of nutrient supply in patients might modify environmental tissue conditions, which may influence the interactions between intestinal epithelial cells and the extracellular matrix.

Randomised controlled trial of trophic feeding and gut motility

OBJECTIVES

To determine the effect of trophic feeding on gastric emptying and whole gut transit time in sick preterm infants.

METHODS

A randomised, controlled, prospective study of 70 infants weighing less than 1750 g at birth, who were receiving ventilatory support, was performed. Group TF (33 infants) received trophic feeding from day 3 (0.5 ml/h if birthweight less than 1 kg, 1 ml/h if greater or equal to 1 kg) in addition to parenteral nutrition until ventilatory support finished. Group C (37 infants) received parenteral nutrition alone until ventilatory support finished. Expressed breast milk or a preterm formula were given according to maternal preference. Gastric emptying was assessed within 24 hours of nutritive milk feeding equal to 90 ml/kg/day, using ultrasound scans to measure the reduction in the gastric antral cross sectional area after a feed. Whole gut motility was assessed at both 3 and 6 weeks of age by measuring the whole gut transit time (WGTT) of the marker carmine red.

RESULTS

There was no significant difference between groups in their gastric half emptying time, median difference (95% confidence interval) 2.6 (-5.9, 13.9) minutes. The WGTT was significantly faster (p < 0.05) in group TF at both 3 and 6 weeks; median difference -13 (-47, -0.1) and -12.5 (-44, -0.5) hours, respectively.

CONCLUSIONS

Trophic feeding enhances whole gut motility but not gastric emptying. This effect could subsequently improve milk tolerance in sick preterm infants.

Short bowel syndrome

Short bowel syndrome has significant morbidity and is potentially lethal especially when intestinal loss is extensive. The pathophysiology of short bowel syndrome, its aetiology, prognosis and our understanding of the mechanisms of adaptation are reviewed. Management by a multi-disciplinary nutritional care team is advocated and should be directed to the maintenance of growth and development, the promotion of intestinal adaptation, the prevention of complications and the establishment of enteral nutrition. The choice of enteral feed, the role of drugs and the use of pro-adaptive nutrients and agents are discussed. Complications including cholestasis and catheter related sepsis are outlined with strategies to reduce them. Finally the roles of secondary surgical interventions including transplantation are discussed.

Nutritional support in malnourished paediatric patients

An imbalance between a person's energy requirements and his or her dietary protein and caloric supply is the source of protein energy malnutrition (PEM), which compounds the problems of any underlying disease. Malnutrition may occur quite rapidly in critically ill patients, particularly those suffering from sepsis, setting up a vicious cycle with worsening of the PEM. This chapter examines the main consequences of PEM, the means whereby appropriate nutrition may be provided, and risks for severely malnourished paediatric patients in hospital. If the gastrointestinal tract can be used for refeeding, it should be used. When the gastrointestinal tract is unable to meet the protein and energy requirements, parenteral nutrition (PN) is required. PN is efficient but carries a high risk of metabolic complications known as the refeeding syndrome and directly related to the homeostatic changes secondary to severe PEM. Catch-up growth may be achieved by using appropriate nutritional support. Changes in body composition have to be assessed during the course of renutrition.

Nutritional management of enteropathy

The prognosis for nutritional management of enteropathy in children is good when the enteropathy is reversible with the use of a food elimination diet, such as cow's-milk-sensitive enteropathy, but is poor when enteropathy is irreversible, such as microvillous atrophy. However, nutritional management is central to the care of all children with small intestinal enteropathy. Enteral nutrition (provision of liquid formula diets by mouth or by tube) is possible in most cases, but in some children with intractable diarrhea, parenteral nutrition needs to supplement enteral feeding. The choice of enteral feeding ranges from elemental to partial hydrolysate.

Successful use of a chicken-based diet for the treatment of severely malnourished children with persistent diarrhea: a prospective, randomized study

OBJECTIVE

To evaluate the efficacy of a chicken-based diet for the treatment of persistent diarrhea in severely malnourished children.

STUDY DESIGN

Prospective, randomized, double-blind study that compared a chicken-based diet with elemental (Vivonex) and soy (Nursoy) diets. Hospitalized children with third-degree malnutrition and persistent diarrhea, aged 3 to 36 months, were included. Diets were isocaloric and given nasogastrically at 150 ml/kg per day in progressively increasing concentrations.

RESULTS

Fifty-six children were included (18 received Vivonex, 19 Nursoy, 19 chicken). They had a mean age of 6.4 +/- 4.4 months, a mean weight of 3604 +/- 1232 gm, and a mean weight-for-age percentage of 51.4% +/- 7.2%. Sixty-four percent had associated conditions on admission to the hospital. Forty-one children (73.2%) were successfully treated (13 Vivonex, 13 Nursoy, 15 chicken). There were no differences in diarrheal outcomes, and all groups had significant weight gain. Failure was independent of the diet and was associated with the presence of infection on admission. There was a significantly higher nitrogen balance in the children from the chicken group (358.2 +/- 13 mg/kg per day) than in those receiving Vivonex (226.6 +/- 61) or Nursoy (291-4 +/- 111.6; p < 0.05) groups.

CONCLUSIONS

The chicken-based diet was as effective as Vivonex or Nursoy. It is well tolerated, inexpensive, and widely available and thus represents an effective and inexpensive alternative to the treatment of severely malnourished children with persistent diarrhea.

Bedside placement of pH-guided transpyloric small bowel feeding tubes in critically ill infants and small children

BACKGROUND AND METHODS

The small bowel of critically ill infants and small children was cannulated using a soft feeding tube with a pH sensor at the distal tip. By monitoring pH, the tubes were guided through the stomach into the small bowel.

RESULTS

Successful placements were performed in 36 of 37 (97%) attempts in 29 critically ill patients whose age was 7.9 +/- 6.3 months and weight was 5.9 +/- 2.6 kg. Continuous jejunal feedings were administered for 3.7 +/- 3.1 weeks without difficulties or complications in all but one patient.

CONCLUSION

pH-guided jejunal tube placement provides a safe, easy bedside alternative to fluoroscopic, endoscopic or surgical placement in critically ill infants and small children.

Home-made modular diet versus semi-elemental formula in the treatment of chronic diarrhoea of infancy: a prospective randomized trial

Considerable success in the management of chronic diarrhoea has been reported using a modular diet (MD), with gradual increments in every nutrient toward a full-strength formula. As the commercially prepared constituents are unavailable in Croatia, we have developed a home-made MD based on boiled minced chicken meat, sunflower oil emulsion, sucrose and cornflour. A full range of vitamins and minerals are added. The value of this MD was compared to a semi-elemental formula (SF) Pregomin. Eighteen infants with severe chronic diarrhoea were randomly assigned to receive either MD of SF. Both groups were comparable with respect to sex, age, and degree of malnutrition. Duration of diarrhoea, feed tolerance, anthropometry, and biochemistry were compared after 4 weeks of treatment.

RESULTS

(1) diarrhoea was significantly shorter (3 vs 7 days; P < 0.01) and nutritional recovery started earlier (5 vs 9 days; P < 0.01) in MD group; (2) median weight gain in the SF group was 100 g/week, compared to 171 g/week in MD group (P < 0.05); (3) in two patients from the SF group, diarrhoea persisted, but they achieved complete recovery when changed to MD.

CONCLUSION

A MD made in the hospital kitchen was superior to a SE formula in the treatment of chronic diarrhoea of infancy.

Prognostic factors in hospitalized children with persistent diarrhea: implications for diet therapy

A dietary algorithm for management of persistent diarrhea in developing countries, using locally available foods, is yet to be standardized. We identified factors related to poor outcome among 75 malnourished hospitalized male patients aged 3-48 months with persistent diarrhea (> or = 14 days) treated on soy and cereal-based diet (Diet I). The 28 patients with stool output > 60 g/k body weight on the sixth or the seventh treatment day were considered diarrhea treatment failures on Diet I. In the univariate analysis, breast feeding (p < 0.001), carbohydrate malabsorption based on low stool pH or reducing substances > 0.5% (p = 0.03), initial 24-h purge rate (p = 0.001), pneumonia (p = 0.003), or probable septicemia (p = 0.03) were associated with diarrhea treatment failures. Although 16 of these 28 patients responded to systemic antibiotics without dietary modification, all but one of the remaining recovered on a chicken puree, glucose, and oil formulation. Twenty-six children had weight loss after 7 days on Diet I as compared with the postrehydration weight. These children had lower mean age (p = 0.05), lower food intake in the first 24 h (p = 0.05) and during the initial 7 days (p < 0.01), and a higher initial excretion of enteroaggregative Escherichia coli (32 vs. 8%; p = 0.01). In the logistic regression model, significant risk factors for diarrhea treatment failures were initial purge rates, carbohydrate malabsorption, and intercurrent systemic infection; only low food intake was associated with significant risk for weight loss. The significant association of diarrhea treatment failures with carbohydrate malabsorption suggests that in the initial diet itself, part of polysaccharide be substituted with sucrose or glucose to obtain the right balance between osmolarity and energy density. Our data suggest that prompt identification and treatment of systemic infection is critical, as its eradication achieved recovery in more than half of the treatment failures without a dietary change.

The human intestinal response to enteral nutrients: a review

This review identifies the factors which influence mucosal integrity during enteral nutrition. These include biliary and pancreatic secretions, trophic influences of endocrine and gastrointestinal polypeptides, intestinal blood flow, and innervation. Fiber, bacterial fermentation products, purines, and glutamines are potential essential nutrients which may not be provided by parenteral nutrition. However, contrary to experience in animal models, the specific advantages of intraluminal delivery of nutrients for the maintenance of mucosal integrity and structure remain unproven in the human. Current evidence in the human suggests that changes in small bowel structure and function when enteral nutrients are excluded are minor and rapidly reversible as long as general nutritional status is maintained.

Postenteritis enteropathy in infancy. A prospective study of 10 patients with special reference to growth pattern, long-term outcome and incidence

Ten patients, who developed postenteritis enteropathy with chronic diarrhoea, failure to thrive and small intestinal mucosal damage after an episode of acute gastroenteritis, were studied prospectively. All patients experienced severe growth retardation. Maximum deviation of height and weight from mean values of age-correlated normal children were -1.7 and -3.1 SD (median values), respectively, as compared to -0.1 and 0 SD before onset of the illness. One child died after 14 months of illness. The long-term outcome was satisfactory for the 9 surviving children. For these children, treatment with an elemental diet (in some cases supplemented initially with parenteral nutrition) and later a lactose-free diet lead to resolution of diarrhoea within periods ranging from 0.5 to 10 months. The phase of catch-up growth lasted from 4 to 36 months, resulting in final height and weight deviating -0.6 and -0.8 SD (median values), respectively, from normal mean values. Attempt to predict duration of diarrhoea or length of catch-up growth phase by means of age, weight before illness, characteristics of small intestinal biopsy or maximum deviation of height or weight were unsuccessful. The incidence of postenteritis enteropathy for children of North European ethnic origin was estimated to be 7.6/1,000,000 children below 7 years of age/year, corresponding to 1.2/1,000 children hospitalized for acute gastroenteritis.

Nutritional therapy for infants with diarrhea

The appropriate choice of treatment for infants with diarrhea has long provoked debate. Growth of infants with diarrhea is adversely affected by associated diseases including anorexia, malabsorption, catabolic response to infection, and iatrogenic starvation. To prevent the negative effects of diarrhea on the nutrition of infants, continued feeding during the active and early convalescent phases has been recommended. Although this concept is not new, until recently it has been little used in the treatment of diarrhea. In this article we examine the current knowledge about, and trends in, feeding infants with diarrhea. We will discuss treatments for the well-nourished infant with acute diarrhea, the infant with prolonged diarrhea, and the malnourished infant. Information regarding the use of local staples will also be provided.

The response to dietary treatment of patients with chronic post-infectious diarrhea and lactose intolerance

The response to dietary treatment of patients with chronic post-infectious diarrhea and lactose intolerance was prospectively studied in 29 infants less than 1 year of age. All had gastroenteritis with diarrhea which persisted for more than 3 weeks. In the hospital, diarrhea continued and lactose intolerance was documented while being fed half-strength cow's milk formula. They were given dietary treatment with one of three formulas used for treatment of diarrhea in infancy. Improvement of diarrhea was more frequently achieved with Pregestimil when given as the initial therapy than with the other two formulas. With Pregestimil nine of 10 patients improved whereas only four of nine infants fed Portagen and one of 10 patients initially treated with soy formula improved. Pregestimil was also effective in three of five patients who initially failed to improve with Portagen and in four of eight patients tried with soy formula with or without carbohydrate. Additionally, in the patients who improved, recovery was more rapidly achieved with Pregestimil than with the other two formulas. Formula failures were due to intolerance to glucose polymers in three patients, possibly to protein in seven infants, and an intolerance to all nutrients in five patients. The improvement of the diarrhea was slower in patients who had evidence of colitis in rectal biopsies regardless of the dietary treatment given, but was not correlated with other variables, i.e., etiology of diarrhea, jejunal histology, or duration of diarrhea prior to treatment. However, as a group, the patients who failed to respond to Pregestimil were younger (less than 3 months of age), had more formula changes and associated infections, and were given more antibiotics; they also had more prolonged diarrhea before treatment and more severe jejunal mucosal lesions and jejunal bacterial overgrowth. The data suggests that Pregestimil seems to be the most effective formula for the treatment of infants with chronic post-infectious diarrhea and lactose intolerance.

Enteral nutrition by tube

When oral intake is unsatisfactory or contraindicated, maintenance of nutrition by tube feeding is an alternative to the parenteral route. A large volume of research data supports the decision to use the enteral route whenever possible. Entry of food into the alimentary tract is a stimulus to structural and functional maintenance of that tract. Enteral nutrition can be given via indwelling nasoesophageal, pharyngostomy, esophagostomy, percutaneous or surgical gastrostomy, or enterostomy tube. Use of an appropriate catheter, familiarity with the technique used, and careful patient selection and monitoring are important factors in successful tube feeding. Blenderized pet food diets should be fed whenever possible; commercially available liquid diets provide an alternative when tube caliber or patient factors preclude the use of blenderized foods.

Changes in the gastrointestinal tract during enteral or parenteral feeding

Intestinal adaptation, in terms of increasing intestinal length and weight, usually occurs rapidly after small-bowel resection. However, this response depends on provision of enteral nutrients. If total parenteral nutrition without enteral feeding is prolonged, hypoplasia of the intestinal mucosa results. Adaptation is probably mediated through the presence of luminal nutrients, particularly glutamine, which is preferentially used by the intestine. However, systemic hormonal factors, possibly gastrin, cholecystokinin, and glucagon, also influence intestinal adaptation. Thus, in the management of short-bowel syndromes, enteral nutrition should be added to total parenteral nutrition as soon as possible.

Nutritional support of hospitalized patients

Effective nutritional support requires sound knowledge of both basic and clinical nutrition of dogs and cats as well as familiarity with products and delivery systems. Case management includes assessment of nutritional status and estimation of fuel sources. Most starved or stressed patients use fatty acids for over 70 per cent kcalME and protein for over 20 per cent kcalME. Approximate kcal needs are calculated from maintenance energy equations. Most patients respond best to enteral nutrition. Meat-based pet foods, liquid enteral products, and nutrient modules are offered in slurries or are tube-fed. Management includes careful monitoring of patients and gradual transitions to diets with more complex nutrient sources.

Human milk and the rate of small intestinal mucosal recovery in protracted diarrhea

STUDY OBJECTIVE

To determine whether human milk accelerates the recovery rate of injured small intestinal mucosa.

DESIGN

Randomized, controlled trial.

SETTING

County and nonprofit, private urban hospitals.

PATIENTS

Moderately to severely malnourished infants less than 6 months of age who required parenteral nutrition for treatment of protracted diarrhea.

INTERVENTIONS

Either a human milk preparation (n = 7) or sterile water (n = 9) was administered by continuous nasogastric feeding (14 mL/kg/d) over a 2-week study period while the infants received parenteral nutrition.

MEASUREMENTS AND MAIN RESULTS

Small intestine perfusion studies and biopsies were performed at the beginning and end of the study. Age, duration of prior illness, severity of malnutrition, glucose and water absorption, disaccharidase activities, atrophy of villi, and nutritional intake were comparable in both groups of infants. At the end of the 2-week study, improvement toward normal sucrase activity and intraepithelial lymphocytes was found in significantly fewer infants in the milk group than in the water group. No differences were noted in glucose and water absorption or in lactase and maltase activities as a function of the milk versus water treatment.

CONCLUSIONS

Human milk did not accelerate functional recovery of the small intestinal mucosa.

Diarrhea in tube-fed burn patients: incidence, etiology, nutritional impact, and prevention

The hypermetabolic state observed in thermally injured patients warrants aggressive nutritional management. Enteral support is the preferred route of nutrient delivery, however diarrhea is reported to be a persistent complication of continuous nasogastric or nasoduodenal hyperalimentation. Diarrhea adds to problems in patient care, disturbs fluid and electrolyte balance, and worsens nutritional status. There has been the impression that tube feeding hyperosmolality, antibiotics, and low serum albumin induce diarrhea. However, in view of the sparsity of published work, a prospective study was undertaken to determine the incidence of diarrhea and to define factors associated with its cause. Of the 50 patients studied, 16 (32%) developed diarrhea. Stool cultures were negative for pathogenic organisms. Although the risk of diarrhea was associated with antibiotics (p less than 0.005), several nutrients also had an impact. Results demonstrated a significant relationship between dietary lipid content (p less than 0.05) or vitamin A intake (p less than 0.001) and diarrhea. Implementation of tube feeding within 48 hrs postburn was also associated with a decreased incidence of diarrhea (p less than 0.001). This paper describes a modular tube feeding program in which diarrheal frequency is lessened (p less than 0.0001). Surprisingly, tube feeding osmolality, drugs used to prevent stress ulcers, or hypoalbuminemia did not have an adverse effect on intestinal absorption. The cause of diarrhea in burn patients is obviously multifactorial. It is concluded that a low fat (less than 20% of caloric intake), vitamin A enriched (greater than 10,000 IU/day), early enteral support program maximizes conditions which promote tube feeding tolerance while minimizing nutrient malabsorption during the nutritional rehabilitation of thermal injury.

Experimental models for the investigation of water and solute transport in man. Implications for oral rehydration solutions

For patients suffering from mild to moderate dehydration, oral rehydration therapy has proved a simple and efficacious treatment. There remains, however, a need to develop improved oral rehydration solutions (ORS), and suitable experimental models are required to develop and assess new formulations. The ideal model for such investigations would take into account rates of gastric emptying, influx and efflux of water and solutes in the intestine, and the consequent changes in body composition. As no such definitive model is currently available, a variety of techniques are used to examine parts of the process of intestinal absorption. Clinical studies which assess the recovery of dehydrated patients during therapy using different ORS will ultimately evaluate the efficacy of treatment. However, ethical considerations, the relative insensitivity of this technique and the exacting nature of such studies make this approach unsuitable for the development of specific ORS. Gastric emptying of solutions can be determined by a variety of techniques, among which the radioactive tracer method offers the advantage of having no direct effect on the emptying rate, giving almost continuous measurement and allowing the use of relatively small volumes of fluids. Perfusion techniques allow measurement of the net flux of water and solute in predetermined sections of the intact human intestine. Measurement of the rate of accumulation in the circulation of orally ingested tracer molecules for water and solutes can estimate unidirectional flux. This method allows for the rates of gastric emptying and intestinal absorption of the test substance, but the rate of efflux of the tracer from the vascular space must be known to calculate net uptake. Each of these models has limitations, and care must be taken in interpreting the results in a clinical context. However, their use in the development of improved formulations is well established.