Low-dose enteral feeding is beneficial during total parenteral nutrition

Possible clinical outcomes using early enteral nutrition in individuals with allogeneic hematopoietic stem cell transplantation: A single-center retrospective study

OBJECTIVES

Intensive nutritional support during allogeneic hematopoietic stem cell transplantation (allo-HSCT) yields improved clinical outcomes. However, the clinical implications of early enteral nutrition (EN) in allo-HSCT remain unclear. This retrospective study was conducted to determine the significance of early EN in individuals who underwent allo-HSCT, and the association between early nutritional intervention and clinical outcomes, including the status of the intestinal microbiome.

METHODS

Thirty-one participants received EN before conditioning. The intestinal microbiota was examined by meta 16S rRNA gene sequencing of fecal samples.

RESULTS

The median body mass variation was only -0.35 kg on day 60. The probability of 2-y overall survival was 61.1%. The cumulative incidence of treatment-related mortality was 17.4%, and those of acute graft-versus-host disease were 32.3% (grades II-IV) and 3.2% (grades III-IV). Chronic graft-versus-host disease was observed in four participants. Dysbiosis of the intestines and acute graft-versus-host disease occurred simultaneously, and Enterococcus species were abundant.

CONCLUSIONS

Our results suggest that early nutritional support can improve the outcomes for individuals who have undergone allo-HSCT and can maintain homeostasis of their intestinal microbiome. Future prospective clinical trials are required to elucidate the role of EN in allo-HSCT and the association between the intestinal microbiome and EN.

Insights into the role of intestinal microbiota in hematopoietic stem-cell transplantation

The gut microbiota (GM) is able to modulate the human immune system. The development of novel investigation methods has provided better characterization of the GM, increasing our knowledge of the role of GM in the context of hematopoietic stem-cell transplantation (HSCT). In particular, the GM influences the development of the major complications seen after HSCT, having an impact on overall survival. In fact, this evidence highlights the possible therapeutic implications of modulation of the GM during HSCT. Insights into the complex mechanisms and functions of the GM are essential for the rational design of these therapeutics. To date, preemptive and curative approaches have been tested. The current state of understanding of the impact of the GM on HSCT, and therapies targeting the GM balance is reviewed herein.

Direct hyperbilirubinemia in newborns with gastroschisis

BACKGROUND

Patients with gastroschisis and prolonged total (or partial) parenteral nutrition (PN) commonly develop direct hyperbilirubinemia (DH).

OBJECTIVE

To quantify the prevalence and severity of DH in newborns with gastroschisis and characterize the diagnostic work-up for DH in this patient population.

DESIGN/METHODS

Retrospective chart review of patients born with gastroschisis between 2005 and 2015 for the first 6 months of life.

RESULTS

29 patients were identified with gastroschisis. Mean gestational age and birthweight were 36.4 (± 1.8) weeks and 2.5 (± 0.6) kg. 41% were treated with primary reduction versus staged closure. Peak total and direct bilirubin (DB) levels were 10.17 ± 6.21 mg/dL and 5.58 ± 3.94 mg/dL, respectively. 23 patients (79.3%) were diagnosed with DH and 78.2% underwent additional work-up for hyperbilirubinemia consisting of imaging and laboratory studies, none of which revealed a cause for DH other than the presumed PN-associated cholestasis. In all patients, DB began to decline within 1-10 days of initiation of enteral feeds.

CONCLUSION(S)

DH is common in patients with gastroschisis and is unlikely to be associated with pathology aside from PN. Additional work-up may lead to unnecessary resource utilization.

LEVELS OF EVIDENCE

Case series with no comparison group, Level IV.

Better early outcome with enteral rather than parenteral nutrition in children undergoing MAC allo-SCT

There is no consensus on the type of nutritional support to introduce in children undergoing allogeneic stem cell transplantation (allo-SCT) after myeloablative conditioning (MAC). This retrospective, multicenter, observational study compared the early administration of enteral nutrition (EN group, n = 97) versus parenteral nutrition (PN group, n = 97) in such patients with matching for important covariates. The primary endpoint was the study of day 100 overall mortality. The early outcome at day 100 was better in EN group regarding mortality rate (1% vs. 13%; p = 0.0127), non relapse mortality (1% vs. 7%; p = 0.066), acute GVHD grades II-IV (37% vs. 54%; p = 0.0127), III-IV (18% vs. 34%; p = 0.0333) and its gut localization (16% vs. 32%; p = 0.0136). Platelet engraftment was better in EN group than in PN group for the threshold of 20 G/L (97% vs. 80% p < 0.0001) and 50 G/L (92% vs. 78%, p < 0.0001). The length of stay was shorter in EN group (28 vs. 52 days, p < 0.0001). There were no differences between the two groups regarding the polynuclear neutrophil engraftment, infection rate or mucositis occurrence. These results suggest that, in children undergoing MAC allo-SCT, PN should be reserved to the only cases when up-front EN is insufficient or impossible to perform.

The Efficacy of an Enteral Access Protocol for Feeding Trauma Patients

BACKGROUND

Proper enteral access to deliver specialized nutrition support in critically injured patients can be difficult, time consuming, and costly. We designed a protocol with interdisciplinary input to facilitate early enteral access in our trauma patients. Our primary objective was to determine if the protocol improved our ability to obtain small-bowel access in patients within 48 hours of their admission to the surgical intensive care unit (SICU). Secondary objectives were to examine the efficacy of the protocol by evaluating parenteral nutrition (PN) use, adequacy of enteral caloric delivery, and clinical outcomes including pneumonia and sepsis rates, SICU length of stay (LOS), hospital LOS, and mortality before and after its implementation.

METHODS

The medical records of 51 trauma patients admitted to the SICU, who met inclusion criteria, were reviewed retrospectively and divided into 2 groups. Patients in group 1 were admitted before protocol implementation (1997-1998, n = 17). Patients in group 2 were admitted after protocol implementation (1998-2000, n = 34).

RESULTS

Small-bowel access was achieved earlier in group 2 compared with group 1 [2.2 +/- 2 days vs 5.4 +/- 8 days, respectively (p = .04)]. PN was used less frequently in group 2 at 41.2% (14/34) as opposed to 64.7% (11/17) in group 1 (p = .05). There was a reduction in the number of days to reach caloric goal from 4.9 days in group 1 to 3.9 days in group 2 (n.s.). Clinical outcomes were similar in both groups.

CONCLUSIONS

The use of a protocol was effective in the achievement of prompt small bowel access. The number of days to reach caloric goal decreased after protocol implementation, but not to a statistically significant degree. However, we were able to detect a significant reduction in the use of PN.

Partial Enteral Nutrition Preserves Elements of Gut Barrier Function, Including Innate Immunity, Intestinal Alkaline Phosphatase (IAP) Level, and Intestinal Microbiota in Mice

Lack of enteral nutrition (EN) during parenteral nutrition (PN) leads to higher incidence of infection because of gut barrier dysfunction. However, the effects of partial EN on intestina linnate immunity, intestinal alkaline phosphatase (IAP) and microbiota remain unclear. The mice were randomized into six groups to receive either standard chow or isocaloric and isonitrogenous nutritional support with variable partial EN to PN ratios. Five days later, the mice were sacrificed and tissue samples were collected. Bacterial translocation, the levels of lysozyme, mucin 2 (MUC2), and IAP were analyzed. The composition of intestinal microbiota was analyzed by 16S rRNA pyrosequencing. Compared with chow, total parenteral nutrition (TPN) resulted in a dysfunctional mucosal barrier, as evidenced by increased bacterial translocation (p < 0.05), loss of lysozyme, MUC2, and IAP, and changes in the gut microbiota (p < 0.001). Administration of 20% EN supplemented with PN significantly increased the concentrations of lysozyme, MUC2, IAP, and the mRNA levels of lysozyme and MUC2 (p < 0.001). The percentages of Bacteroidetes and Tenericutes were significantly lower in the 20% EN group than in the TPN group (p < 0.001). These changes were accompanied by maintained barrier function in bacterial culture (p < 0.05). Supplementation of PN with 20% EN preserves gut barrier function, by way of maintaining innate immunity, IAP and intestinal microbiota.

A randomized placebo controlled trial of preoperative carbohydrate drinks and early postoperative nutritional supplement drinks in colorectal surgery

AIM

There is evidence that preoperative carbohydrate drinks and postoperative nutritional supplements improve the outcome of colorectal surgery. There is little information on their individual contribution.

METHOD

A prospective four-arm double-blind controlled trial was carried out in which patients were randomized to carbohydrate or placebo drinks preoperatively and a polymeric supplement or placebo drink postoperatively. The primary outcome was insulin resistance (using the short insulin tolerance test and HOMA-IR). Secondary outcomes included handgrip strength, pulmonary function, intestinal permeability and postoperative complications.

RESULTS

A total of 120 patients were randomized to four demographically well matched groups. Patients who received preoperative and postoperative supplements had better glucose homeostasis (P = 0.004), peak expiratory flow rate (P = 0.035), handgrip strength (P = 0.002) and less insulin resistance (P = 0.001) compared with those who only received placebo drinks.

CONCLUSION

Oral nutritional supplements given preoperatively and postoperatively improve postoperative handgrip strength, pulmonary function and insulin resistance. A weaker effect was seen in patients who received supplements either preoperatively or postoperatively. Oral nutritional supplements should be given both preoperatively and postoperatively.

Enteral nutrition in the critically ill patient

Timing and route of nutrition provided to critically ill patients can affect their outcome. Early enteral nutrition has been shown to decrease specifically infectious morbidity in the critically ill patient. There is a small group of patients who are malnourished on arrival to the intensive care unit and in these patients parenteral nutrition is beneficial.

Cholestasis and growth in neonates with gastroschisis

PURPOSE

The aim of this study was to determine the incidence of cholestasis and the correlation between cholestasis and weight-for-age z scores in parenteral nutrition-dependent neonates with gastroschisis.

METHODS

A single-center retrospective review of 59 infants born with gastroschisis from January 2000 to June 2007 was conducted. Demographic and clinical data were collected and analyzed. Subjects were divided into cholestatic and noncholestatic groups. Statistical analyses included the Student t test, Wilcoxon rank sum test, Fisher exact test, and a general linear model.

RESULTS

Fifty-nine neonates with gastroschisis were identified, and 16 (28%) of 58 patients developed cholestasis. Younger gestational age and cholestasis were found to be independently associated with weight-for-age z score in 30 of 58 patients with available long-term follow-up data.

CONCLUSIONS

Parenteral nutrition-dependent neonates with gastroschisis remain at considerable risk for the development of cholestasis. Both gestational age and cholestasis were found to be independent risk factors, predisposing these neonates to poor postnatal growth.

Tolerability and efficacy of a low-volume enteral supplement containing key nutrients in the critically ill

BACKGROUND & AIMS

To compare early supplementation with antioxidants and glutamine using a low-volume enteral supplement containing key nutrients to an energy adjusted standard elementary diet and to investigate its effect on clinical efficacy and tolerability in critically ill patients with sepsis/SIRS. The primary endpoints were length of stay in the ICU and sufficient enteral feed.

METHODS

This was a randomized, prospective, single-blind, controlled study in 58 critically ill patients (56.9% male, mean age 46.7 years, mean APACHE II score 21.6). They received either a low-volume enteral supplement containing key nutrients or a diluted standard nutrition solution. After 10 or 14 days inflammatory parameters, catecholamine need, and maximal enteral delivery were determined.

RESULTS

Patients receiving a low-volume enteral supplement containing key nutrients did not reach sufficient enteral feed more often than controls (76 vs. 62%, respectively, p = 0.17). The difference in vitamin E and selenium uptake was higher in the treatment group than controls (12.4 vs. 3.7 and 54.7 vs. 16.3, respectively, p ≤ 0.011). Parameters such as fever, antibiotic treatment, artificial ventilation, and death were comparable. This was also true for days of ICU or hospital stay (33 ± 23 and 49 ± 34 days, respectively).

CONCLUSIONS

The low-volume enteral supplement containing key nutrients was well tolerated and led to a better vitamin E and selenium supply. However, it did not affect length of ICU or hospital stay. Further studies are necessary to determine which disease-specific subgroups may benefit from this supplementation or which group may be harmed.

Combining enteral with parenteral nutrition to improve postoperative glucose control

The provision of parenteral nutrition (PN) to ‘stressed’ patients often results in hyperglycaemia, which may be detrimental. In animal models limited amounts of enteral nutrition (EN) improve intestinal integrity and stimulate intestinal incretin production, which may lead to improved glucose control. We set out to assess if combining EN with PN results in improved glucose homeostasis rather than PN given alone. We conducted a randomised trial in a university teaching hospital of patients undergoing a ‘curative’ oesophagectomy for adenocarcinoma. Differences between the two intervention groups were assessed for continuous glucose measurement, insulin sensitivity using insulin tolerance tests (ITT) and homeostasis model analysis (HOMA), the incretin glucose-dependent insulinotropic polypeptide (GIP) and intestinal permeability. The combination of PN with EN resulted in lower interstitial glucose concentrations (P = 0·002), reduced insulin resistance, improved insulin sensitivity (HOMA-insulin resistance (IR)P = 0·045; HOMA βP = 0·037; ITTP = 0·006), improved intestinal permeability (P < 0·001) and increased GIP (P = 0·01) when compared with PN alone. The combination of EN with PN, when compared with PN alone, results in reduced glucose concentrations, reduced insulin resistance, increased incretins and improvements in intestinal permeability.

Reversal of parenteral nutrition-induced gut mucosal immunity impairment with small amounts of a complex enteral diet

BACKGROUND

Although parenteral nutrition (PN) prevents progressive malnutrition, lack of enteral nutrition (EN) during PN leads to gut associated lymphoid tissue (GALT) atrophy and dysfunction. Administering a small amount of EN with PN reportedly prevents increases in intestinal permeability. However, its effects on GALT remain unclear. We analyzed the minimum amount of EN required to preserve gut immunity during PN.

METHODS

Male Institute of Cancer Research mice underwent jugular vein catheter insertion and tube gastrostomy. They were randomized into four groups to receive isocaloric and isonitrogenous nutritional support with variable EN to PN ratios (EN 0, EN 33, EN 66, and EN 100). EN was provided with a complex enteral diet. After 5 days of feeding, the mice were killed and whole small intestines were harvested. GALT lymphocytes were isolated and counted. Their phenotypes were analyzed by flow cytometry. IgA levels of small intestinal washings were analyzed with enzyme-linked immunosorbent assay.

RESULTS

Body weight changes did not differ between any two of the groups. Peyer's patch lymphocyte numbers increased in proportion to EN amount, whereas lamina propria lymphocyte numbers were significantly higher in the EN 100 than in the EN 0 group, with no marked increases in the EN 33 and EN 66 groups. Small intestinal IgA levels increased EN amount-dependently and reached a plateau at EN 66.

CONCLUSIONS

A small amount of EN partially reverses PN-induced GALT changes, suggesting beneficial but limited effects on gut mucosal immunity.

Early enteral nutrition in acute pancreatitis--benefits and limitations

INTRODUCTION

The application of enteral feeding as part of the treatment of acute pancreatitis goes back more than a decade now. In this review, the authors outline the indications and limitations of enteral feeding in the treatment of acute pancreatitis using up-to-date evidence-based data.

RESULTS AND DISCUSSION

Latest meta-analyses suggest that early enteral feeding reduces effectively the incidence of infective complications and shortens hospital stay. In addition, recently published randomized controlled trials indicate that it may reduce mortality as well.

CONCLUSION

However, the role of immune-enhancing ingredients, such as glutamine or omega-3 fatty acids, combined with enteral nutrition is uncertain, and the published studies are too few to make any treatment recommendation. Supplementation of enteral feeding with probiotics is a potentially promising alternative, but further well-designed multi-centric trials are necessary to prove their role in the treatment of acute pancreatitis.

Total parenteral nutrition causes circumferential intestinal atrophy, remodeling of the intestinal wall, and redistribution of eosinophils in the rat gastrointestinal tract

Total parenteral nutrition (TPN) is held to cause intestinal atrophy and weaken mechanical and immunological barriers. To monitor the degree of atrophy caused by TPN, female Sprague-Dawley rats were, for 8 days, maintained on TPN (n = 6) and compared to identically housed controls given food and water ad libitum (n = 6). Specimens from jejunum, ileum, and colon were taken for histology and morphometric analysis. Topographic distribution and presence of eosinophils, by eosinophil peroxidase (EPO) staining, were examined in the gastric fundus, jejunum, ileum, and colon. Atrophy in terms of a markedly reduced circumference was noted throughout the intestinal tract in all rats subjected to TPN. The width of jejunal and ileal villi was narrowed and the length of jejunal villi was decreased. Furthermore, submucosal thickness in the jejunum and ileum increased. The height of ileal enterocytes remained unaltered. The number of goblet cells decreased in jejunal but not in ileal villi. The Paneth cells, suggested to play important roles in innate defense, increased in size. In the gastric fundus a marked increase in eosinophils was revealed predominantly in the mucosa and submucosa. The number and distribution of jejunal and ileal eosinophils were identical to those of controls. In colon from TPN rats, a redistribution of eosinophils was noted, causing a "band-like" accumulation of eosinophils in the basal portion of the mucosa. In conclusion, TPN causes gut atrophy and an increase in Paneth cell size. Eosinophils increase in number in the gastric fundus and a topographic redistribution occurs in the colon.

Development of the infant intestine: implications for nutrition support

The incidence of preterm births has continued to increase over the past 25 years, and therefore the optimal feeding of these infants is an important clinical concern. This review focuses on intestinal development and physiology, with a particular emphasis on developmentally immature functions of the preterm intestine and the resulting implications for nutrition therapies used to feed the preterm infant.

Nutrition support in acute pancreatitis

The benefit of early enteral nutrition (EN) for the disease process and for patient outcome in severe acute pancreatitis is dramatic. A narrow window of opportunity exists during which there is potential for EN to decrease disease severity and reduce overall complications. Most patients with severe pancreatitis tolerate enteral feeds. Any signs of symptom exacerbation or increasing inflammation in response to EN may be ameliorated by subtle adjustments in the feeding strategy. In this manner, provision of EN represents primary therapy in the management of the patient with acute pancreatitis and is emerging as the gold standard of therapy in nutrition support for this disease process.

Enteral Feeding and Early Outcomes of Patients Undergoing Allogeneic Stem Cell Transplantation Following Myeloablative Conditioning

The purpose of this study was to evaluate the impact of enteral nutrition on early outcome of patients after myeloablative allogeneic stem cell transplantation (allo-SCT). From January 2001 to January 2003, 22 patients agreed to receive enteral nutrition via a nasogastric feeding tube; the remaining 23 patients received parenteral nutrition (n=22) or standard oral feeding (n=1). Early complications and factors influencing 100-day overall survival (OS) were investigated. Patients who received enteral nutrition developed less often acute-grade III/IV graft-versus-host disease (18%) than those who did not (35%) (P=0.011). In addition, this group showed lower mortality from infection during the first 100 days after transplantation. In multivariate analyses, only the absence of enteral nutrition was found to adversely influence 100-day OS with a hazard ratio of 8.3. Enteral nutrition is a safe and effective method for feeding allo-SCT patients. A randomized trial is warranted to confirm its advantage on early patient outcome.

Total parenteral nutrition-related gastroenterological complications

Total parenteral nutrition is a life saving therapy for patients with chronic gastrointestinal failure, being an effective method for supplying energy and nutrients when oral or enteral feeding is impossible or contraindicated. Clinical epidemiological data indicate that total parenteral nutrition may be associated with a variety of problems. Herein we reviewed data on the gastroenterological tract regarding: (i) total parenteral nutrition-related hepatobiliary complications; and (ii) total parenteral nutrition-related intestinal complications. In the first group, complications may vary from mildly elevated liver enzyme values to steatosis, steatohepatitis, cholestasis, fibrosis and cirrhosis. In particular, total parenteral nutrition is considered to be an absolute risk factor for the development of biliary sludge and gallstones and is often associated with hepatic steatosis and intrahepatic cholestasis. In general, the incidence of total parenteral nutrition-related hepatobiliary complications has been reported to be very high, ranging from 20 to 75% in adults. All these hepatobiliary complications are more likely to occur after long-term total parenteral nutrition, but they seem to be less frequent, and/or less severe in patients who are also receiving oral feeding. In addition, end-stage liver disease has been described in approximately 15-20% of patients receiving prolonged total parenteral nutrition. Total parenteral nutrition-related intestinal complications have not yet been adequately defined and described. Epidemiological studies intended to define the incidence of these complications, are still ongoing. Recent papers confirm that in both animals and humans, total parenteral nutrition-related intestinal complications are induced by the lack of enteral stimulation and are characterised by changes in the structure and function of the gut. Preventive suggestions and therapies for both these gastroenterological complications are reviewed and reported in the present review.

Early Enteral Nutrition in Young Dogs Suffering from Haemorrhagic Gastroenteritis

The purpose of this study was to investigate clinical and metabolic effects of combined parenteral and oral nutrition compared with parenteral nutrition in young dogs with haemorrhagic gastroenteritis in a prospective clinical study. Dogs with acute gastroenteritis received either parenteral nutrition (group PN, n = 9) or combined parenteral and early enteral nutrition (group EN, n = 10). Infusions were compounded from amino acids, lipids, glucose and electrolyte/glucose solutions [149 g/l glucose, 20 g/l triglycerides, 40 g/l amino acids and 4009 kJ metabolizable energy/l (957 kcal ME/l)], and supplemented with potassium, phosphate and trace elements. Group EN received additionally a hydrolysed diet (74 kJ/kg BW(0.75) on day 2 and 148 kJ/kg BW(0.75) on days 3 and 4). Glucose, triglycerides, protein, albumin, fibrinogen, urea, creatinine, alkaline phosphatase, glutamate dehydrogenase and glutamate pyruvate transaminase were measured before and during the infusions, haematological traits only before the infusions. Statistics included two-factorial anova and subsequent t-test or Wilcoxon test (P < 0.05). All dogs of group EN survived compared with seven of nine patients in group PN. Most dogs in the EN group vomited within half an hour after introduction of oral feeding on day 2 but tolerance for food increased on days 3 and 4. The general health status and faecal and blood parameters of the surviving dogs were similar (P > 0.05) between the groups. In all dogs leucocytes increased during the treatment period, haematocrit and haemoglobin levels declined. Infusions increased blood glucose and triglycerides (P < 0.05); however, no adverse signs were observed. Early enteral nutrition was possible after a short period of adaptation, however, vomiting can be a severe problem. The evaluation of clinical benefits of early enteral nutrition in young dogs with haemorrhagic gastroenteritis requires further investigations.

Liver disease due to parenteral and enteral nutrition

Liver disease due to parenteral and enteral nutrition is a well-recognized iatrogenic phenomenon, but its cause and pathogenesis have not been clearly elucidated. Various mechanisms have been postulated, but it is likely that the cause is multifactorial with significant interplay among several factors. A preventive approach to management is ideal but awaits a more complete understanding of the pathophysiology. A variety of management strategies has been proposed in small case series, but level 1 evidence-based guidelines have yet to be established. Although an abundance of both clinical and animal studies exist regarding liver disease associated with parenteral nutrition (PN), there is a paucity of data regarding enteral nutrition (EN)-associated hepatic disease. The latter probably reflects differences in the frequency and severity of PN- versus EN-associated liver disease. This article addresses the two routes of nutritional support individually, with the major focus on PN-associated liver disease.

Microvascular responses to adenosine help explain functional and pathologic differences between intestinal segments

BACKGROUND

Many physiologic (post-prandial hyperemia), pathologic (inflammatory bowel disease), and clinical (enteral feeding) phenomena involve changes in microvascular blood flow to the intestine. Adenosine (Ado) derived from energy metabolism causes vasodilation and appears to be involved in some of these events. The Ado-mediated control mechanisms appear to vary with the diameter of the microvessels and the function of the tissue. This suggests the possibility that Ado-based microvascular control varies between anatomic intestinal segments and microvascular levels in those intestinal segments.

METHODS

In vivo digital intravital microscopy was used to measure the responses of larger distributing (A1) and smaller premucosal (A3) vessels to Ado in intact neurovascular loops of jejunum and terminal ileum of the rat. Dose-response curves to Ado were determined.

RESULTS

Microvascular dilation and augmented blood flow to Ado were significantly greater in the jejunum than in the terminal ileum. Ado-induced dilation was greater in the smaller A3 than in the larger A1 microvessels.

DISCUSSION

These data indicate (1) different vasodilator mechanisms for the jejunum and the terminal ileum, (2) a greater role for Ado-related microvascular control in the jejunum compared with the ileum, and (3) a greater Ado-related control in the premucosal (A3) vessels. These findings suggest that Ado-mediated microvascular effects could explain why some clinical phenomena vary in intensity in selective intestinal segments, and are likely to involve different microvascular control mechanisms in the different segments. Knowledge of these Ado mechanisms could be beneficial in certain clinical scenarios to control blood flow during pathologic conditions.

Effects of combined nutritional therapy on acute necrotizing pancreatitis in rats in the early phase of the disease

The aim of this study was to investigate the influence of a small amount of enteral nutrition along with parenteral nutrition on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats in the early phase of disease. The induction of ANP resulted in a significant increase in mortality rate, intestinal permeability, bacterial infection in the pancreas and extrapancreatic organs, pancreatic necrosis and serum activity of urea and amylase, and a significant decrease in concentrations of calcium, protein and albumin. But no difference was observed between the pancreatitis groups. Significant hyperglycemia and increased liver transaminase activity were observed in rats treated with combined nutritional therapy (CNT). CNT did not improve the course of acute pancreatitis, intestinal permeability, bacterial translocation, or reduce the extent of acinar cell injury in ANP and is therefore unlikely to be of benefit in patients with pancreatitis in the early period.

Multicentre, cluster-randomized clinical trial of algorithms for critical-care enteral and parenteral therapy (ACCEPT)

BACKGROUND

The provision of nutritional support for patients in intensive care units (ICUs) varies widely both within and between institutions. We tested the hypothesis that evidence-based algorithms to improve nutritional support in the ICU would improve patient outcomes.

METHODS

A cluster-randomized controlled trial was performed in the ICUs of 11 community and 3 teaching hospitals between October 1997 and September 1998. Hospital ICUs were stratified by hospital type and randomized to the intervention or control arm. Patients at least 16 years of age with an expected ICU stay of at least 48 hours were enrolled in the study (n = 499). Evidence-based recommendations were introduced in the 7 intervention hospitals by means of in-service education sessions, reminders (local dietitian, posters) and academic detailing that stressed early institution of nutritional support, preferably enteral.

RESULTS

Two hospitals crossed over and were excluded from the primary analysis. Compared with the patients in the control hospitals (n = 214), the patients in the intervention hospitals (n = 248) received significantly more days of enteral nutrition (6.7 v. 5.4 per 10 patient-days; p = 0.042), had a significantly shorter mean stay in hospital (25 v. 35 days; p = 0.003) and showed a trend toward reduced mortality (27% v. 37%; p = 0.058). The mean stay in the ICU did not differ between the control and intervention groups (10.9 v. 11.8 days; p = 0.7).

INTERPRETATION

Implementation of evidence-based recommendations improved the provision of nutritional support and was associated with improved clinical outcomes.

Bedside placement of small bowel feeding tubes in hospitalized patients:

OBJECTIVE

The benefits of enteral nutrition when compared with parenteral nutrition are well established. However, provision of enteral nutrition may not occur for several reasons, including lack of optimal feeding access. Gastric feeding is easier to initiate, but many hospitalized patients are intolerant to gastric feeding, although they can tolerate small bowel feeding. Many institutions rely on costly methods for placing small bowel feeding tubes. Our goal was to evaluate the effectiveness of a hospital-developed protocol for bedside-blind placement of postpyloric feeding tubes.

METHODS

The Surgical Nutrition Service established a protocol for bedside placement of small bowel feeding tubes. The protocol uses a 10- or 12-French, 110-cm stylet containing the feeding tube; 10 mg of intravenous metoclopramide; gradual tube advancement followed by air injection and auscultation; and an abdominal radiograph for tube position confirmation. In a prospective manner, consults received by the surgical nutrition dietitian for feeding tube placements were followed consecutively for a 10-mo period. The registered dietitian recorded the number of radiograph examinations, the final tube position, and the time it took to achieve tube placement.

RESULTS

Because all consults were included, feeding tube placements occurred in surgical and medical patients in the intensive care unit and on the ward. Of the 135 tube placements performed, 129 (95%) were successfully placed postpylorically, with 84% (114 of 135) placed at or beyond D3. Average time for tube placement was 28 min (10 to 90 min). One radiograph was required for 92% of the placements; eight of 135 (6%) required two radiographs. No acute complications were associated with the tube placements.

CONCLUSIONS

Hospitalized patients can receive timely enteral feeding with a cost-effective feeding tube placement protocol. The protocol is easy to implement and can be taught to appropriate medical team members through proper training and certification.

Nutrition support for the patient with an open abdomen after major abdominal trauma

OBJECTIVE

Nutrition support in the severely injured trauma patient is crucial to minimize the hypermetabolic stress response. Even though enteral nutrition is the preferred method of feeding, it is not always feasible after multiple trauma. We present a complex nutritional case in a patient who sustained severe abdominal trauma with a severe liver injury, rib fractures, and pulmonary contusion.

METHODS

The patient required several repeat laparotomies, abdominal packing, and temporary abdominal closure. The clinical course was complicated by hypotension requiring multiple vasopressors; coagulopathy requiring more than 35 U of packed red cells, more than 50 U of fresh frozen plasma, and more than 80 U of platelets; acute renal failure requiring dialysis; and pneumonia and acute respiratory distress syndrome requiring intricate ventilator management. Nutrition intervention began on post-trauma day 4 with total parenteral nutrition due to hypotension, resuscitation, and massive bowel edema; by post-trauma day 8. the patient was receiving goal nutrients.

RESULTS

On post-trauma day 27, bowel edema was significantly less, and a nasoenteric feeding tube was placed and enteral feeding initiated. By post-trauma day 31, full enteral feeds were tolerated, and total parenteral nutrition was stopped. Nutrient provision was adjusted daily to account for organ and metabolic changes including hepatic, pulmonary, and renal dysfunction. The patient did well and was eventually extubated and eating a regular diet.

CONCLUSION

With careful monitoring and adjusting of the nutritional plan, a hypermetabolic complex trauma patient with an open abdomen can be fed optimally, safely, and successfully despite increased bowel edema and multiple organ dysfunction.

Acidomucin goblet cell expansion induced by parenteral nutrition in the small intestine of piglets

Total parenteral nutrition (TPN) impairs small intestine development and is associated with barrier failure, inflammation, and acidomucin goblet cell expansion in neonatal piglets. We examined the relationship between intestinal goblet cell expansion and molecular and cellular indices of inflammation in neonatal piglets receiving TPN, 80% parenteral + 20% enteral nutrition (PEN), or 100% enteral nutrition (control) for 3 or 7 days. Epithelial permeability, T cell numbers, TNF-alpha and IFN-gamma mRNA expression, and epithelial proliferation and apoptosis were compared with goblet cell numbers over time. Epithelial permeability was similar to control in the TPN and PEN jejunum at day 3 but increased in the TPN jejunum by day 7. By day 3, intestinal T cell numbers were increased in TPN but not in PEN piglets. However, goblet cell expansion was established by day 3 in both the TPN and PEN ileum. Neither TNF-alpha nor IFN-gamma mRNA expression in the TPN and PEN ileum correlated with goblet cell expansion. Thus goblet cell expansion occurred independently of overt inflammation but in association with parenteral feeding. These data support the hypothesis that goblet cell expansion represents an initial defense triggered by reduced epithelial renewal to prevent intestinal barrier failure.

Feeding methods for the preterm infant

As more very immature preterm infants survive, provision of enteral feedings has become a major focus of concern. Although many aspects of gastrointestinal function are immature in the preterm infant, the ability of the preterm neonate to process and absorb enteral nutrients appears to be adequate enough to sustain nutritional needs. Few prospective randomized trials have compared the efficacy of different feeding methods. However, some studies have compared differing routes of feeding, rates of feeding, and volume of feeding. The ability to successfully digest enteral feedings may be inhibited or enhanced by pharmacological agents. The need to modify a feeding strategy can be monitored by tracking several measurements prospectively. Finally, there is a need to assess ongoing dietary needs of preterm infants for discharge planning.

Should indirect calorimetry be used as part of nutritional assessment?

The use of indirect calorimetry in the design of nutritional support regimens is poorly appreciated by clinicians, who fail to recognize the importance of providing a sufficient volume of enteral feeding to critically ill patients. In contrast to the overfeeding that routinely occurred in the past with the provision of total parenteral nutrition, patients placed on the enteral route of support tend to be underfed because of problems with intolerance and frequent cessation. Clearly identifying and coming as close as possible to the caloric goal may be required to achieve the therapeutic endpoints of enteral tube feeding (which include maintenance of gut integrity, attenuation of the stress response, prophylaxis against stress-induced gastropathy, and stimulation of immune function). Indirect calorimetry is a convenient, accessible, and highly accurate instrument for the measurement of caloric requirements and is a valuable tool for the optimization of nutritional support in the intensive care unit.

Minimal enteral nutrient requirements for intestinal growth in neonatal piglets: how much is enough?

BACKGROUND

Parenterally nourished preterm infants commonly receive minimal enteral feedings, the aim being to enhance intestinal function. Whether this regimen increases intestinal growth has not been established.

OBJECTIVE

Our objective was to determine the minimal enteral nutrient intakes necessary to stimulate and to normalize neonatal intestinal growth.

METHODS

Intestinal growth and cell proliferation were quantified in neonatal pigs given equal amounts of an elemental nutrient solution for 7 d. Different groups (n = 5-7 per group) received 0%, 10%, 20%, 40%, 60%, 80%, or 100% of total nutrient intake enterally, with the remainder given parenterally.

RESULTS

In the jejunum, wet weight, protein mass, and villus height were significantly greater at enteral intakes >40%. Stimulation of ileal protein mass required a higher enteral intake (60%). In both segments, abrupt increases in DNA mass, crypt depth, ornithine decarboxylase activity, and crypt cells in S-phase occurred between enteral intakes of 40% and 60%. Circulating concentrations of glucagon-like peptide-2 and peptide YY, but not gastrin, increased significantly between enteral intakes of 40% and 60% and closely paralleled indexes of cell proliferation.

CONCLUSIONS

The minimal enteral nutrient intake necessary to increase mucosal mass was 40% of total nutrient intake, whereas 60% enteral nutrition was necessary to sustain normal mucosal proliferation and growth. Our results imply that providing <40% of the total nutrient intake enterally does not have significant intestinal trophic effects.

Small amount of low-residue diet with parenteral nutrition can prevent decreases in intestinal mucosal integrity

OBJECTIVE

To investigate the suitable combination ratio of low-residue diet (LRD) and parenteral nutrition (PN) for nutritional support of surgical patients.

SUMMARY BACKGROUND DATA

Bacterial translocation (BT) is a severe complication of total parenteral nutrition (TPN). However, it is sometimes impossible to supply sufficient amounts of nutrients to surgical patients by the enteral route. The authors reported previously that concomitant use of LRD with PN provided preferable nutritional support for patients undergoing surgery for colorectal cancer.

METHODS

Ninety male Donryu rats were used for three experiments. In experiment 1, rats were divided into two groups to receive TPN or total enteral nutrition with LRD. In experiment 2, rats were divided into six groups, receiving variable amounts of LRD. In experiment 3, rats were divided into five groups to receive isocaloric nutritional support with variable proportions of PN and LRD. Intestinal permeability was assessed by monitoring urinary excretion of phenolsulfonphthalein. BT was assessed in tissue cultures of mesenteric lymph nodes and spleen.

RESULTS

In experiment 1, increases in intestinal permeability and BT were observed in rats maintained on 7-day TPN, but not in those maintained on total enteral nutrition for up to 14 days. In experiment 2, the changes in body weight of rats were correlated with the dose of LRD. However, the intestinal permeability was increased only in rats receiving LRD at 15 kcal/kg per day. In experiment 3, additive LRD corresponding to 15% of total caloric intake prevented increases in intestinal permeability and BT.

CONCLUSION

Combined nutritional therapy consisting of PN and small amounts of LRD can provide better nutritional support than TPN for surgical patients.

Enteral insulin-like growth factor-I augments intestinal disaccharidase activity in piglets receiving total parenteral nutrition

BACKGROUND

Partial enteral nutrition is administered to infants on parenteral nutrition to stimulate intestinal function. Herein, the hypothesis that supplementation of partial enteral nutrition with insulin-like growth factor-I would augment intestinal development was investigated.

METHODS

One-day-old piglets (n = 29) were randomly assigned to five dietary treatment groups: 100% of energy as enteral formula, 100% of energy as total parenteral nutrition, or 80% parenteral nutrition/20% enteral formula supplemented with either 0, 0.2, or 1 mg/kg insulin-like growth factor-I for 7 days. Weight gain, intestinal weight, morphology, protein, and DNA content and disaccharidase activity and mRNA expression were assessed.

RESULTS

Parenterally fed piglets had similar whole body weight gain and serum hormone concentrations but reduced intestinal mucosal weight, villus height, and sucrase and lactase activity compared with 100% enterally fed pigs. Partial enteral nutrition alone increased mucosal weight and protein content, villus height, and disaccharidase activity compared with 100% parenterally fed piglets. No effect of the lower dose of insulin-like growth factor-I (0.2 mg/kg per day) was observed, but supplementing partial enteral nutrition with 1 mg insulin-like growth factor-I/kg further increased villus width and cross-sectional area and disaccharidase activity compared with partial enteral nutrition alone. Lactase mRNA expression was not affected by insulin-like growth factor-I, suggesting that the primary site of regulation of lactase by insulin-like growth factor-I occurs after transcription.

CONCLUSIONS

Enteral insulin-like growth factor-I augmented intestinal morphology and disaccharidase activity in parenterally fed piglets over that observed with partial enteral nutrition alone. Thus enteral insulin-like growth factor-I may represent an efficacious clinical adjunct to promote intestinal development of parenterally fed neonates.

Free radical formation in infants: the effect of critical illness, parenteral nutrition, and enteral feeding

BACKGROUND/PURPOSE

An increase in free radical activity has been observed in patients suffering from a variety of illnesses and has been correlated with disease severity. Free radical production is increased by the administration of total parenteral nutrition (TPN) and may be linked to its adverse effects. Some of the complications of TPN can be ameliorated by partial enteral feeding. The aim of this study was to investigate free radical activity during critical illness and during the administration of parenteral nutrition.

METHODS

Three groups of surgical infants were studied: (1) control infants (n = 8) before minor surgery, (2) stable infants on the ward recovering from a major operation (n = 24), (3) critically ill infants in the neonatal intensive care unit (NICU, n = 28). Fourteen patients in the ward and 17 patients in NICU were receiving parenteral nutrition. Of the 31 patients on TPN, 9 were also receiving minimal enteral feeding (3% to 24% of total calorie intake). Plasma malondialdehyde (MDA), an index of free radical activity, was measured in all 60 infants. The Paediatric Risk of Mortality (PRISM) score was obtained on NICU patients. The cytokines tumor necrosis factor (TNF-alpha) and interleukin 6 (IL-6) were measured in 25 patients.

RESULTS

Plasma MDA was significantly higher in (1) the stable patients on the ward compared with control patients (P < .001) and (2) patients in NICU compared with stable patients in the ward (P < .001). Parenteral nutrition was associated with higher levels of plasma MDA both in stable patients in the ward and critically ill infants in NICU. There was no correlation between the PRISM score and MDA. In patients not receiving TPN there is a correlation between MDA and TNF-alpha (r = 0.54, P = .02) and between MDA and IL-6 (r = 0.74, P = .001). The level of free radical activity in patients on TPN is not changed by partial enteral feeding.

CONCLUSIONS

Critical illness causes a rise in free radical production. Parenteral nutrition causes a significant elevation in free radical activity in both stable infants in the ward and critically ill infants in NICU. The addition of minimal enteral feeding to parenteral nutrition does not reduce free radical activity. We hypothesize that the parenteral nutrition solution directly initiates free radical production.

The role of enterocytes in gut dysfunction

Stem cells in the intestinal epithelium give rise to enterocytes, goblet cells, enteroendocrine cells, and Paneth cells. Each of these cell lines plays a role in cytoprotection of the intestinal mucosa. In particular, it has been demonstrated that mature enterocytes can act as antigen presenting cells. Parenteral and enteral nutrition are used to nourish critically ill patients. However, these regimens are unfortunately associated with gut atrophy. Glutamine, the preferred intestinal nutrient, reverses this gut atrophy and plays a key role in maintaining the barrier function of the gut. Specific nutrients (putrescine, spermidine, spermine) have been used to modulate intestinal adaption. In addition, ornithine has been shown to act as a regulator of intestinal adaption. In this review, we discuss the relationship between the biology of enterocytes and failure of the gut barrier.

The effect of minimum luminal nutrition on mucosal cellularity and immunity of the gut

Many catabolic patients can only consume small volumes of enteral nutrients. The aim of this study was to evaluate markers of cellularity and immunity in the small intestine of rats randomized to receive 6 days of parenteral nutrition, 25% enteral and 75% parenteral nutrition (i.e. minimum luminal nutrition) or enteral nutrition. The same glutamine-enriched solution was used for both parenteral and enteral nutrition. Enteral nutrition was associated with the least amount of jejunal atrophy (P<0.01), with the results from the minimum luminal nutrition group approximating those of the parenteral nutrition group. Parenteral nutrition was associated with the greatest number of CD2+ cells (P< 0.05) and the lowest CD4/CD8 cell ratio (P< 0.01) in the jejunal mucosa. In essence, we failed to demonstrate that there are any appreciable benefits associated with the enteral consumption of 25% of a nutrient load.

Early increase in intestinal permeability in patients with severe acute pancreatitis: correlation with endotoxemia, organ failure, and mortality

Sepsis accounts for 80% of deaths from acute pancreatitis. This study aimed to investigate early changes in intestinal permeability in patients with acute pancreatitis, and to correlate these changes with subsequent disease severity and endotoxemia. The renal excretion of enterally administered polyethylene glycol (PEG) 3350 and PEG 400 was measured within 72 hours of onset of acute pancreatitis to determine intestinal permeability. Severity was assessed on the basis of APACHE II scores and C-reactive protein measurements. Serum endotoxin and antiendotoxin antibodies were measured on admission. Eight-five patients with acute pancreatitis (mild in 56, severe in 29) and 25 healthy control subjects were studied. Urinary excretion of PEG 3350 (median) was significantly greater in patients who had severe attacks (0.61%) compared to those with mild disease (0.09%) and health control subjects (0.12%) (P <0. 0001), as was the permeability index (PEG 3350/400 excretion) (P <0. 00001). The permeability index was significantly greater in patients who subsequently developed multiple organ system failure and/or died compared with other severe cases (0.16 vs. 0.04) (P = 0.0005). The excretion of PEG 3350 correlated strongly with endotoxemia (r = 0.8; P = 0.002). Early increased intestinal permeability may play an important role in the pathophysiology of severe acute pancreatitis. Therapies that aim to restore intestinal barrier function may improve outcome.