Enteral versus parenteral feeding. Effects on septic morbidity after blunt and penetrating abdominal trauma

ErbB receptors and their growth factor ligands in pediatric intestinal inflammation

The ErbB tyrosine kinases (epidermal growth factor receptor (EGFR), ErbB2/HER2, ErbB3, and ErbB4) are cell surface growth factor receptors widely expressed in many developing mammalian tissues, including in the intestinal tract. Signaling elicited by these receptors promotes epithelial cell growth and survival, and ErbB ligands have been proposed as therapeutic agents for intestinal diseases of pediatric populations, including inflammatory bowel disease (IBD), necrotizing enterocolitis (NEC), and inflammation associated with total parenteral nutrition (TPN). Furthermore, emerging evidence points to reduced ErbB ligand expression and thus reduced ErbB activity in IBD, NEC, and TPN models. This review will discuss the current understanding of the role of ErbB receptors in the pathogenesis and potential treatment of pediatric intestinal inflammation, with focus on the altered signaling in disease and the molecular mechanisms by which exogenous ligands are protective.

Proceedings of the 2013 A.S.P.E.N. Research workshop: the interface between nutrition and the gut microbiome: implications and applications for human health [corrected]

The human and earth microbiomes are among the most important biological agents in understanding and preventing disease. Technology is advancing at a fast pace and allowing for high-resolution analysis of the composition and function of our microbial partners across regions, space, and time. Bioinformaticists and biostatisticians are developing ever more elegant displays to understand the generated megadatasets. A virtual cyberinfrastructure of search engines to cross-reference the rapidly developing data is emerging in line with technologic advances. Nutrition science will reap the benefits of this new field, and its role in preserving the earth and the humans who inhabit it will become evidently clear. In this report we highlight some of the topics of an A.S.P.E.N.-sponsored symposium held during Clinical Nutrition Week in 2013 that address the importance of the human microbiome to human health and disease.

Is early enteral nutrition initiated within 24 hours better for the postoperative course in esophageal cancer surgery?

BACKGROUND

Early enteral nutrition within 24 h after surgery has become a recommended procedure. In the present study, we retrospectively examined whether initiating EN within 24 h after esophagectomy improves the postoperative course.

METHODS

Among 103 patients who underwent thoracic esophagectomy for esophageal cancer, we enrolled the cases in which EN was initiated within 72 h after surgery. The patients were divided into two groups: EN started within 24 h (Group D1) and EN started at 24 - 72 h (Group D2-3). Clinical factors including days for first fecal passage, dose of postoperative albumin infusion, difference in serum albumin between pre- and postoperation, incidence of postoperative infection, and use of total parenteral nutrition were compared. Statistical analyses were performed by the Mann-Whitney U test and Chi square test, with significance defined as P < 0.05.

RESULTS

There was no significant difference between the groups in clinical factors. While pneumonia was significantly more frequent in Group D1 than in Group D2-3 (P = 0.0308), the frequency of infectious complications was comparable between the groups.

CONCLUSION

Initiating EN within 24 h showed no advantage for the postoperative course in esophageal cancer, and thus EN should be scheduled within 24 - 72 h, based on the patient condition.

IL-25 improves IgA levels during parenteral nutrition through the JAK-STAT pathway

INTRODUCTION

Parenteral nutrition (PN) impairs mucosal immunity and increases the risk of infection in part via lower IgA levels at mucosal surfaces. Transport of immunoglobulin A (IgA) across the mucosa to the gut lumen depends on the epithelial transport protein, polymeric immunoglobulin receptor (pIgR), which is reduced during PN. In vitro, studies demonstrate that IL-4 up-regulates pIgR production via Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling. Because IL-4 stimulates IgA and is reduced during PN, we hypothesized that the suppressed pIgR is a result of decreased JAK-1 and STAT-6 phosphorylation. Because IL-4 is mediated by IL-25, we also hypothesized that PN + IL-25 would restore luminal IgA by increasing phosphorylated JAK-1 and STAT-6, resulting in increased tissue pIgR and luminal IgA.

METHOD

Experiment 1: 2 days after intravenous cannulation, male Institute of Cancer Research mice were randomized to chow (n = 11) or PN (n = 9). Experiment 2: 2 days after intravenous cannulation, male Institute of Cancer Research mice were randomized to chow (n = 12), PN (n = 10), or PN + 0.7 μg of exogenous IL-25 (n = 11) per day. After 5 days, distal ileum tissue was collected, homogenized, and protein extracted for JAK-STAT expression levels using a phospho-specific antibody microarray. Tissue was homogenized to measure pIgR expression via Western blot or fixed in 4% paraformaldehyde to measure pIgR expression via immunohistochemistry. Small intestinal wash fluid was collected and IgA was quantified using enzyme-linked immunosorbent assay.

RESULTS

Experiment 1: PN significantly reduced phosphorylated JAK-1 and STAT-6 compared with chow. PN also decreased the tissue levels of the Th2 cytokines, IL-4 and IL-13, as well as pIgR, and luminal IgA compared with chow. Experiment 2: Exogenous administration of PN + IL-25 increased the phosphorylated JAK-1 and STAT-6 compared with PN alone. IL-25 completely restored expression of IL-13 to chow levels. IL-4, pIgR, IgA, and phosphorylated JAK-1 were significantly increased with IL-25 treatment compared with PN but failed to reach levels measured in chow. STAT-6 was significantly increased with IL-25 treatment compared with chow and PN.

CONCLUSIONS

PN significantly decreases the JAK-STAT pathway by reducing levels of phosphorylated STAT-6 and JAK-1. Consistent with our previous work, sIgA, pIgR, and IL-4 decreased with PN, whereas the addition of IL-25 to PN reversed these decreases and demonstrated the role of the JAK-STAT pathway in vivo during PN.

Guideline clinical nutrition in patients with stroke

Stroke is regularly accompanied by dysphagia and other factors associated with decreased nutritional intake. Dysphagia with aspiration pneumonia and insufficient nutritional intake lead to worse outcome after stroke.

This guideline is the first chapter of the guideline “Clinical Nutrition in Neurology” of the German Society for Clinical Nutrition (DGEM) which itself is one part of a comprehensive guideline about all areas of Clinical Nutrition. The thirty-one recommendations of the guideline are based on a systematic literature search and review, last updated December 31, 2011. All recommendations were discussed and consented at several consensus conferences with the entire DGEM guideline group. The recommendations underline the importance of an early screening and assessment of dysphagia and give advice for an evidence based and comprehensive nutritional management to avoid aspiration, malnutrition and dehydration.

Influence of fish to soybean oil ratio on hepatic mononuclear cell function and survival after intraportal bacterial challenge in parenterally fed mice

BACKGROUND

Parenteral nutrition (PN) is indispensable for meeting the caloric and substrate needs of patients who cannot receive adequate amounts of enteral nutrition. However, PN decreases hepatic mononuclear cell (MNC) numbers and impairs their functions. We examined the effects of various ratios of ω-3 to ω-6 polyunsaturated fatty acids on hepatic MNC number and function in a murine model. We focused on serum liver enzymes, lipid metabolism, cytokine production, histopathology, and the outcomes of an intraportal bacterial challenge.

MATERIAL AND METHODS

In experiment 1, male Institute of Cancer Research mice were randomized to CHOW, 67%, 33%, 16%, 8%, 4%, and 0% fish oil (FO)-PN groups. After receiving their respective diets for 5 days, 1.0 × 10(7) Pseudomonas aeruginosa were delivered by intraportal injection. Survival was observed ≤ 7 days after injection. Liver histologies after intraportal bacterial challenge were examined in the CHOW, 33%, 8%, and 0% FO-PN groups. In experiment 2, the mice were divided into 4 groups: CHOW, 33%, 8%, and 0% FO-PN. After the mice had been fed for 5 days, MNC were isolated. Hepatic MNC were counted and cytokine productions (tumor necrosis factor [TNF]-α and interleukin [IL]-10) by MNC in response to lipopolysaccharide (LPS) were measured. Blood samples were analyzed for lipid metabolism and hepatobiliary biochemical parameters. Liver histologies were also examined.

RESULTS

In experiment 1, survival times were significantly shorter in the 4% and 0% FO-PN groups than in the CHOW group. Survival rates at 168 hours were 100%, 64%, 86%, 73%, 67%, 11%, and 13% in the CHOW, 67%, 33%, 16%, 8%, 4%, and 0% FO-PN groups, respectively. At 72 hours after intraportal bacterial challenge, the 0% FO-PN group showed severe tissue damage, whereas such damage was reduced in the 8% and 33% FO-PN groups. In experiment 2, the CHOW, 33%, 8%, and 0% FO-PN groups showed LPS dose-dependent increases in TNF-α levels. IL-10 levels were also LPS dose-dependently increased in the CHOW and 33% FO-PN groups. However, no marked changes were observed in response to LPS stimulation in either the 8% or the 0% FO-PN group. There were no differences in serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, or total bilirubin among these 4 groups. In the 0% FO-PN group, serum total cholesterol levels were greater than those in the 8% and 33% FO-PN groups. Without bacterial challenge, livers from the 0% FO-PN group showed steatosis, but these changes were attenuated in the 8% and 33% FO-PN groups.

CONCLUSION

The 30-40% ratio of FO to soybean oil with 20% of total calories supplied by lipid seems to be the best PN for preservation of hepatic MNC number and function.

Patients requiring perioperative nutritional support

One of the most important factors affecting outcome and recovery from surgical trauma is preoperative nutritional status. Research in perioperative nutritional support has suffered from a lack of consensus as to the definition of malnutrition, no recognition of which nutrients are important to surgical healing, and a paucity of well-designed studies. In the past decade, there has been some activity to address this situation, recognizing the importance of nutrition as a therapy before surgery, after surgery, and possibly even during surgery.

Microbiota-derived lactate accelerates colon epithelial cell turnover in starvation-refed mice

Oral food intake influences the morphology and function of intestinal epithelial cells and maintains gastrointestinal cell turnover. However, how exactly these processes are regulated, particularly in the large intestine, remains unclear. Here we identify microbiota-derived lactate as a major factor inducing enterocyte hyperproliferation in starvation-refed mice. Using bromodeoxyuridine staining, we show that colonic epithelial cell turnover arrests during a 12- to 36-h period of starvation and increases 12-24 h after refeeding. Enhanced epithelial cell proliferation depends on the increase in live Lactobacillus murinus, lactate production and dietary fibre content. In the model of colon tumorigenesis, mice exposed to a carcinogen during refeeding develop more aberrant crypt foci than mice fed ad libitum. Furthermore, starvation after carcinogen exposure greatly reduced the incidence of aberrant crypt foci. Our results indicate that the content of food used for refeeding as well as the timing of carcinogen exposure influence the incidence of colon tumorigenesis in mice.

Bombesin improves adaptive immunity of the salivary gland during parenteral nutrition

BACKGROUND

The parotid and submandibular salivary glands are gut-associated lymphoid tissues (GALTs) that secrete immune compounds into the oral cavity. Parenteral nutrition (PN) without enteral stimulation decreases GALT function, including intestinal lymphocyte counts and secretory immunoglobulin A (sIgA) levels. Since the neuropeptide bombesin (BBS), a gastrin-releasing peptide analogue, stimulates intestinal function and restores GALT parameters, we hypothesized that PN + BBS would stimulate parotid and salivary gland IgA levels, T lymphocytes, and IgA plasma cell counts compared with PN alone.

METHODS

Male (Institute of Cancer Research) ICR mice received intravenous catheters and were randomized to chow with saline, PN, or PN + BBS (15 µg/tid/mouse) for 5 days (8/group), 2 days after cannulation. Salivary glands were weighed and either frozen for IgA and amylase analysis or fixed for histological analysis of acinar cells, IgA+ plasma cells, and T lymphocytes. Small intestinal wash fluid was collected for IgA regression analysis with salivary glands.

RESULTS

PN reduced organ weight, acinar cell size, and amylase activity compared with chow; BBS had no significant effects on these parameters. Compared with chow, PN significantly reduced salivary gland IgA levels, IgA+ plasma cells, and T lymphocytes. PN + BBS significantly elevated IgA and restored cellularity compared with PN. Salivary gland tissue homogenate IgA levels significantly correlated with intestinal fluid IgA levels.

CONCLUSIONS

Compared with chow, PN results in atrophy of the salivary glands characterized by reduced amylase, IgA, and immune cellularity. BBS has no effect on acinar cells or amylase activity compared with PN but maintains tissue IgA and plasma cells and T-lymphocyte numbers compared with chow.

Clinical review: the critical care management of the burn patient

Between 4 and 22% of burn patients presenting to the emergency department are admitted to critical care. Burn injury is characterised by a hypermetabolic response with physiologic, catabolic and immune effects. Burn care has seen renewed interest in colloid resuscitation, a change in transfusion practice and the development of anti-catabolic therapies. A literature search was conducted with priority given to review articles, meta-analyses and well-designed large trials; paediatric studies were included where adult studies were lacking with the aim to review the advances in adult intensive care burn management and place them in the general context of day-to-day practical burn management.

Truncal vagotomy temporarily decreases the pro- and anti-inflammatory cytokine levels in the small intestine

PURPOSE

The vagus nerve exerts immunomodulatory functions by inhibiting pro-inflammatory cytokine overproduction. Because vagotomy is a standard procedure during the radical operation for esophageal or gastric cancer, the postoperative clinical course might be related to vagotomy-associated changes in the cytokine milieu. We herein examined the gut cytokine kinetics after vagotomy in mice.

METHODS

Thirty-eight male Institute of Cancer Research mice underwent sham or sub-diaphragmatic truncal vagotomy. The whole small intestine was harvested on postoperative day (POD) 14 (sham: vagotomy, n = 9:10) or 20 (n = 9:10). The pro- and anti-inflammatory cytokine levels in the plasma, jejunum, ileum and whole small intestine were evaluated.

RESULTS

The plasma cytokine levels were similar in the vagotomy and sham groups on POD 14 and 20. However, both the pro- and anti-inflammatory cytokine levels tended to be lower on POD 14 and higher on POD 20 in the vagotomy group than in the sham group. With regard to the cytokine kinetics, the jejunal IL-12p70, TNF-α, MCP-1 and IL-10, ileal IL-12p70, TNF-α, IL-6, MCP-1 and IL-10, and whole small intestinal IL-12p70, TNF-α, IFN-γ, MCP-1 and IL-10 of the vagotomy group all significantly increased on POD 20 as compared to POD 14.

CONCLUSION

Vagotomy has a major impact on the gut cytokine milieu. Vagotomy may initially inhibit both pro- and anti-inflammatory cytokine production, while both later increase.

Is early enteral nutrition better for postoperative course in esophageal cancer patients?

We retrospectively examined esophageal cancer patients who received enteral nutrition (EN) to clarify the validity of early EN compared with delayed EN. A total of 103 patients who underwent transthoracic esophagectomy with three-field lymphadenectomy for esophageal cancer were entered. Patients were divided into two groups; Group E received EN within postoperative day 3, and Group L received EN after postoperative day 3. The clinical factors such as days for first fecal passage, the dose of postoperative albumin infusion, differences of serum albumin value between pre- and postoperation, duration of systematic inflammatory response syndrome (SIRS), incidence of postoperative infectious complication, and use of total parenteral nutrition (TPN) were compared between the groups. The statistical analyses were performed using Mann-Whitney U test and Chi square test. The statistical significance was defined as p < 0.05. Group E showed fewer days for the first fecal passage (p < 0.01), lesser dose of postoperative albumin infusion (p < 0.01), less use of TPN (p < 0.01), and shorter duration of SIRS (p < 0.01). However, there was no significant difference in postoperative complications between the two groups. Early EN started within 3 days after esophagectomy. It is safe and valid for reduction of albumin infusion and TPN, for promoting early recovery of intestinal movement, and for early recovery from systemic inflammation.

Parenteral nutrition decreases paneth cell function and intestinal bactericidal activity while increasing susceptibility to bacterial enteroinvasion

INTRODUCTION

Parenteral nutrition (PN) increases the risk of infection in patients with contraindication to enteral feeding. Paneth cells produce and secrete antimicrobial products that protect the mucosa from pathogens. Their loss is associated with increased host-pathogen interactions, mucosal inflammation, and altered microbiome composition.

HYPOTHESIS

We hypothesized that PN reduces Paneth cell product expression, and these changes would reduce bactericidal properties of tissue secretions following cholinergic stimulation, increase mucosal enteroinvasion, and shift the intestinal microbiome.

METHOD

Experiment 1: Male ICR mice were randomized to Chow (n = 8) or PN (n = 8). Ileum tissue was collected for Paneth cell antimicrobial expression using RT-PCR, stimulated with a cholinergic agonist degranulate Paneth cells bactericidal activity, or used to assess bacterial enteroinvasion in EVISC. Experiment 2: Mice were randomized to Chow (n = 11) or PN (n = 8) and ileum washing was collected for 16s pyrosequencing analysis.

RESULTS

Compared to Chow, PN decreased tissue expression of REGIII-g (p < 0.002), lysozyme (p < 0.002), and cryptdin-4 (p < 0.03). At the phylum level, PN decreased total Firmicutes but increased total Bacteroidetes, and Proteobacteria. Functionally, secretions from PN tissue was less bactericidal (p < 0.03) and demonstrated increased susceptibility to enteroinvasion by E coli (p < 0.02).

CONCLUSION

PN without enteral nutrition impairs innate mucosal immune function. Tissue expression of Paneth cell antimicrobial proteins decreases associated with compositional shifts to the microbiome, decreased bactericidal activity of mucosal secretions and greater susceptibility of to enteroinvasion by E coli. These changes may explain in-part the increased risk of infection in parenterally fed patients.

Nutrition therapy for critically ill and injured patients

BACKGROUND

Nutrition support has undergone significant advances in recent decades, revolutionizing the care of critically ill and injured patients. However, providing adequate and optimal nutrition therapy for such patients is very challenging: it requires careful attention and an understanding of the biology of the individual patient's disease or injury process, including insight into the consequent changes in nutrients needed.

OBJECTIVE

The objective of this article is to review the current principles and practices of providing nutrition therapy for critically ill and injured patients.

METHODS

Review of the literature and evidence-based guidelines.

RESULTS

The evidence demonstrates the need to understand the biology of nutrition therapy for critically ill and injured patients, tailored to their individual disease or injury, age, and comorbidities.

CONCLUSION

Nutrition therapy for critically ill and injured patients has become an important part of their overall care. No longer should we consider nutrition for critically ill and injured patients just as "support" but, rather, as "therapy", because it is, indeed, a key therapeutic modality.

Continuous reinfusion of succus entericus associated with fistuloclysis in the management of a complex jejunal fistula on the abdominal wall

INTRODUCTION

Fistuloclysis is an alternative method for enteral nutrition infusion, and has been successfully employed for the management of patients with high output small bowel fistula. However it has some deficiencies also.

PRESENTATION OF CASE

A 42-year-old woman with multiple high output enterocutaneous fistula was submitted to fistuloclysis with reinfusion of chyme, after a period of several complications due to parenteral nutrition.

DISCUSSION

Enteral nutrition provide better nutrition and fewer complications than parenteral nutrition. The enterocutaneous fistula usually does not allow enteral nutrition, however the use of fystuloclysis can fix this issue. The reinfusion of chyme provide the possibility of oral intake and better control of hydroeletrolitics disorders.

CONCLUSION

More studies on the physiological effects of the chyme recirculation could add more data contributing to the clarification of this complex issue, but we believe that patients with high output and very proximal enterocutaneous fistula can be sucessfully treated with fistuloclysis and recirculation of chyme.

Total parenteral nutrition-associated lamina propria inflammation in mice is mediated by a MyD88-dependent mechanism

Enteral nutrient deprivation via total parenteral nutrition (TPN) administration leads to local mucosal inflammatory responses, but the underlying mechanisms are unknown. Wild-type (WT) and MyD88(-/-) mice underwent jugular vein cannulation. One group received TPN without chow, and controls received standard chow. After 7 d, we harvested intestinal mucosally associated bacteria and isolated small-bowel lamina propria (LP) cells. Bacterial populations were analyzed using 454 pyrosequencing. LP cells were analyzed using quantitative PCR and multicolor flow cytometry. WT, control mucosally associated microbiota were Firmicutes-dominant, whereas WT TPN mice were Proteobacteria-domiant. Similar changes were observed in MyD88(-/-) mice with TPN administration. UniFrac analysis showed divergent small bowel and colonic bacterial communities in controls, merging toward similar microbiota (but distinct from controls) with TPN. The percentage of LP T regulatory cells significantly decreased with TPN in WT mice. F4/80(+)CD11b(+)CD11c(dull/-) macrophage-derived proinflammatory cytokines significantly increased with TPN. These proinflammatory immunologic changes were significantly abrogated in MyD88(-/-) TPN mice. Thus, TPN administration is associated with significant expansion of Proteobacteria within the intestinal microbiota and increased proinflammatory LP cytokines. Additionally, MyD88 signaling blockade abrogated decline in epithelial cell proliferation and epithelial barrier function loss.

Intestinal microbial diversity and perioperative complications

BACKGROUND AND AIMS

Enteral nutrient deprivation via parenteral nutrition (PN) in a mouse model leads to a local mucosal inflammatory response. This proinflammatory response leads to a loss of epithelial barrier function and atrophy of the intestine. Although the underlying mechanisms are unknown, a potential contributing factor is the impact PN has on the intestinal microbiome. We recently identified a shift in the intestinal microbial community in mice given PN; however, it is unknown whether such changes occur in humans. We hypothesized that similar microbial changes occur in humans during periods of enteral nutrient deprivation.

METHODS

A series of small bowel specimens were obtained from pediatric and adult patients undergoing small intestinal resection. Mucosally associated bacteria were harvested and analyzed using 454 pyrosequencing techniques. Statistical analysis of microbial diversity and differences in microbial characteristics were assessed between enterally fed and enterally deprived portions of the intestine. Occurrence of postoperative infectious and anastomotic complications was also examined.

RESULTS

Pyrosequencing demonstrated a wide variability in microbial diversity within all groups. Principal coordinate analysis demonstrated only a partial stratification of microbial communities between fed and enterally deprived groups. Interestingly, a tight correlation was identified in patients who had a low level of enteric microbial diversity and those who developed postoperative enteric-derived infections or intestinal anastomotic disruption.

CONCLUSIONS

Loss of enteral nutrients and systemic antibiotic therapy in humans is associated with a significant loss of microbial biodiversity within the small bowel mucosa. These changes were associated with a number of enteric-derived intestinal infections and intestinal anastomotic disruptions.

Nutritional support in patients following damage control laparotomy with an open abdomen

INTRODUCTION

Damage control laparotomy (DCL) and the open abdomen have been well accepted following either severe abdominal trauma or emergency surgical disease. As DCL is increasingly utilized as a therapeutic option, appropriate management of the post-DCL patient is important. Early caloric support by enteral nutrition (EN) in the critically ill patient improves wound healing and decreases septic complications, lung injury, and multi-system organ failure. However, following DCL, nutritional strategies can be challenging and, at times, even daunting.

CONCLUSIONS

Even though limited data exist, the use of early EN following DCL seems safe, provided that the patient is not undergoing active resuscitation or the bowel is not in discontinuity. It is unknown as to whether EN in the open abdomen reduces septic complications, prevents enterocutaneous fistula (ECF), or alters the timing of definitive abdominal wall closure. Future investigation in a prospective manner may help elucidate these important questions.

The clinical role of glutamine supplementation in patients with multiple trauma: a narrative review

Glutamine is considered an essential amino acid during stress and critical illness. Parenteral glutamine supplementation in critically ill patients has been shown to improve survival rate and minimise infectious complications, costs and hospital length-of-stay. However, glutamine supplementation in patients receiving enteral nutrition and the best method of administration are still controversial. The purpose of this article is to provide a narrative review of the current evidence and trials of enteral and parenteral glutamine supplementation in multiple trauma patients. A search in PubMed and EMBASE was conducted and relevant papers that investigated the effect of enteral or parenteral glutamine supplementation in patients with multiple trauma were reviewed. Although recent nutritional guidelines recommend that glutamine supplementation should be considered in these patients, further well-designed trials are required to provide a confirmed conclusion. Due to the inconclusive results of enteral glutamine supplementation trials in patients receiving enteral nutrition, future trials should focus on intravenous glutamine supplementation in patients requiring enteral nutrition and on major clinical outcome measures (e.g. mortality rate, infectious complications).

Advantages of enteral nutrition over parenteral nutrition

It is a strong and commonly held belief among nutrition clinicians that enteral nutrition is preferable to parenteral nutrition. We provide a narrative review of more recent studies and technical reviews comparing enteral nutrition with parenteral nutrition. Despite significant weaknesses in the existing data, current literature continues to support the use of enteral nutrition in patients requiring nutrition support, over parenteral nutrition.

Nutrition support in the critically ill

PURPOSE OF REVIEW

To highlight the recent developments in nutritional support for critically ill patients.

RECENT FINDINGS

Increasing data support the benefits of early initiation of enteral nutrition, with improvements in small intestinal absorption and clinical outcomes. In contrast to the previous belief, recent data suggest caloric administration of greater than 65-70% of daily requirement is associated with poorer clinical outcomes, especially when supplemental parenteral nutrition is used to increase the amount of caloric delivery. The role of supplementary micronutrients and anti-inflammatory lipids has been further evaluated but remains inconclusive, and is not currently recommended.

SUMMARY

Together, current findings indicate that intragastric enteral nutrition should be initiated within 24 h of admission to ICU and supplementary parenteral nutrition should be avoided. Future research should aim to clarify the optimal energy delivery for best clinical outcomes, and the role of small intestinal function and its flora in nutritional care and clinical outcomes.

Parenteral nutrition increases susceptibility of ileum to invasion by E coli

BACKGROUND

Parenteral nutrition (PN), with the lack of enteral feeding, compromises mucosal immune function and increases the risk of infections. We developed an ex vivo intestinal segment culture (EVISC) model to study the ex vivo effects of PN on susceptibility of the ileum to invasion by extra-intestinal pathogenic Escherichia coli (ExPEC) and on ileal secretion of antimicrobial secretory phospholipase A2 (sPLA2) in response to the pathogen.

MATERIALS AND METHODS

Study 1: Using mouse (n = 7) ileal tissue, we examined the effects of ileal region (proximal versus distal) and varying ExPEC inoculum concentrations on ex vivo susceptibility to ExPEC invasion and sPLA2 secretion. Study 2: Ten mice were randomized to oral chow or intravenous PN feeding for 5 d (n = 5/group). Using the EVISC model, we compared the susceptibility of ileal tissue to invasion by ExPEC and sPLA2 secretion in response to the pathogen.

RESULTS

Study 1: The proximal ileum was more susceptible to invasion (P < 0.0001) and secreted lower amounts of sPLA2 (P = 0.0002) than the distal ileum. Study 2: Ileal tissue from PN-fed animals was more susceptible (approximately 4-fold, P = 0.018) to invasion than those from chow-fed animals. Ileal tissue from PN-fed animals secreted less sPLA2 (P < 0.02) than those from chow-fed animals.

CONCLUSIONS

The data illustrate EVISC as a reproducible model for studying host-pathogen interactions and the effects of diet on susceptibility to infections. Specifically, the findings support our hypothesis that PN with the lack of enteral feeding decreases mucosal responsiveness to pathogen exposure and provides a plausible mechanism by which PN is associated with increased risk of infectious complication.

The potential association of later initiation of oral/enteral nutrition on euthyroid sick syndrome in burn patients

Objective. The aim of this study was to determine if early initiation of oral/enteral nutrition in burn patients minimizes the drop in fT3 levels, reduces the potential for euthyroid sick syndrome (ESS), and shortens the length of hospital stay (LHS). Subjects and Methods. We retrospectively evaluated the statistical association of serum fT3, fT4, and TSH at the first (2nd-5th day) and second sample collection (9th-12th day) after the burn injury in 152 burn patients. Three groups were established depending on time of initiation of the oral/enteral nutrition: <24 h before the injury (Group 1), 24-48 h after the injury (Group 2), and >48 h after the injury (Group 3). Results. They were expressed as mean ± standard deviation. We found that LHS and the fT3 levels were statistically different in the 3 groups. The LHS (in days) was, respectively, in each group, 16.77 ± 4.56, 21.98 ± 4.86, and 26.06 ± 5.47. Despite the quantifiable drop in fT3, ESS was present only at the first sample collection (2.61 ± 0.92 days) in Group 3, but there was no group with ESS at the second sample collection (9.89 ± 1.01 days). Our data suggest that early initiation of nutritional supplementation decreases the length of hospitalization and is associated with decreasing fT3 serum concentration depression. Conclusion. Early initiation of oral/enteral nutrition counteracts ESS and improves the LHS in burn patients.

Parenteral nutrition combined with enteral nutrition for severe acute pancreatitis

Background and Aims. Nutritional support in severe acute pancreatitis (SAP) is controversial concerning the merits of enteral or parenteral nutrition in the management of patients with severe acute pancreatitis. Here, we assess the therapeutic efficacy of gradually combined treatment of parenteral nutrition (PN) with enteral nutrition (EN) for SAP. Methods. The clinical data of 130 cases of SAP were analyzed retrospectively. Of them, 59 cases were treated by general method of nutritional support (Group I) and the other 71 cases were treated by PN gradually combined with EN (Group II). Results. The APACHE II score and the level of IL-6 in Group II were significantly lower than Group I (P < 0.05). Complications, mortality, mean hospital stay, and the cost of hospitalization in Group II were 39.4 percent, 12.7 percent, 32 ± 9 days, and 30869.4 ± 12794.6 Chinese Yuan, respectively, which were significantly lower than those in Group I. The cure rate of Group II was 81.7 percent which is obviously higher than that of 59.3% in Group I (P < 0.05). Conclusions. This study indicates that the combination of PN with EN not only can improve the natural history of pancreatitis but also can reduce the incidence of complication and mortality.

A pilot study to explore the safety of perioperative postpyloric enteral nutrition

BACKGROUND

The practice of holding enteral nutrition (EN) 8 hours prior to surgery is common. We hypothesized that it was safe to continue postpyloric EN, and we developed an institutional practice pattern to investigate our hypothesis.

METHODS

Our pilot study included intubated patients in the surgical intensive care unit at Froedtert Memorial Lutheran Hospital who received EN via a nasojejunal (NJ) feeding tube and underwent 1 or more surgical procedures. Demographic, illness, and injury information were collected as well as length of time to NJ placement, time to initiation of EN, EN interruptions, and complications. Additional hours of EN were calculated by totaling the number of hours a patient received EN past midnight on the day of surgery.

RESULTS

A total of 14 patients with mean (SD) age 44.3 (19.9) were included. Patients had a mean (SD) Injury Severity Score (ISS) of 26.1 (9.2) on admission and underwent a total of 38 operations following placement of a feeding tube. The most frequent operation performed was an orthopedic procedure (n = 17; 46.1%). The mean (SD) length of EN interruptions for a single procedure was 222.4 (206.9) minutes. Patients received an additional 11.9 (4.7) hours of EN over the course of their hospitalization and an additional 1064.9 (490) kcal/d per operation. There were no adverse events.

CONCLUSION

Perioperative continuation of postpyloric EN is feasible in some critically ill surgical patients and can result in additional calories provided. A multidisciplinary approach and an institutional policy can increase the likelihood of meeting nutrition goals in these patients.

A multicenter, randomized controlled trial comparing early nasojejunal with nasogastric nutrition in critical illness

OBJECTIVE

Current guidelines recommend enteral nutrition in critically ill adults; however, poor gastric motility often prevents nutritional targets being met. We hypothesized that early nasojejunal nutrition would improve the delivery of enteral nutrition.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Seventeen multidisciplinary, closed, medical/surgical, intensive care units in Australia.

PATIENTS

One hundred and eighty-one mechanically ventilated adults who had elevated gastric residual volumes within 72 hrs of intensive care unit admission.

INTERVENTIONS

Patients were randomly assigned to receive early nasojejunal nutrition delivered via a spontaneously migrating frictional nasojejunal tube, or to continued nasogastric nutrition.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the proportion of the standardized estimated energy requirement that was delivered as enteral nutrition. Secondary outcomes included incidence of ventilator-associated pneumonia, gastrointestinal hemorrhage, and in-hospital mortality rate. There were 92 patients assigned to early nasojejunal nutrition and 89 to continued nasogastric nutrition. Baseline characteristics were similar. Nasojejunal tube placement into the small bowel was confirmed in 79 (87%) early nasojejunal nutrition patients after a median of 15 (interquartile range 7-32) hrs. The proportion of targeted energy delivered from enteral nutrition was 72% for the early nasojejunal nutrition and 71% for the nasogastric nutrition group (mean difference 1%, 95% confidence interval -3% to 5%, p=.66). Rates of ventilator-associated pneumonia (20% vs. 21%, p=.94), vomiting, witnessed aspiration, diarrhea, and mortality were similar. Minor, but not major, gastrointestinal hemorrhage was more common in the early nasojejunal nutrition group (12 [13%] vs. 3 [3%], p=.02).

CONCLUSIONS

In mechanically ventilated patients with mildly elevated gastric residual volumes and already receiving nasogastric nutrition, early nasojejunal nutrition did not increase energy delivery and did not appear to reduce the frequency of pneumonia. The rate of minor gastrointestinal hemorrhage was increased. Routine placement of a nasojejunal tube in such patients is not recommended.

The open abdomen: practical implications for the practicing surgeon

The open abdomen is a necessary sequela after damage-control surgery or abdominal compartment syndrome. Management of the patient in the intensive care unit continues to evolve, with considerations of fluid resuscitation, enteral nutrition, and supportive care. Management of the abdominal contents incorporates several basic techniques and considerations: appropriate temporary covering, enteric injury repair in most patients, placement of an anastomosis in an area of the abdomen with minimal manipulation without exposure to the atmosphere, acquiring enteral access for initiation of enteral nutrition, and ultimate abdominal closure. An understanding of these complex factors is instrumental for the practicing surgeon.

Loss of enteral nutrition in a mouse model results in intestinal epithelial barrier dysfunction

Total parenteral nutrition (TPN) administration in a mouse model leads to a local mucosal inflammatory response, resulting in a loss of epithelial barrier function (EBF). Although, the underlying mechanisms are unknown, a major contributing factor is a loss of growth factors and subsequent critical downstream signaling. An important component of these is the p-Akt pathway. An additional contributing factor to the loss of EBF with TPN is an increase in proinflammatory cytokine abundance within the mucosal epithelium, including TNF-α and IFN-γ. Loss of critical nutrients, including glutamine and glutamate, may affect EBF, contributing to the loss of tight junction proteins. Finding protective modalities for the small intestine during TPN administration may have important clinical applications. Supplemental glutamine and glutamate may be examples of such agents.

Placement of fully covered self-expandable metal stents in patients with locally advanced esophageal cancer before neoadjuvant therapy

BACKGROUND

Most patients with locally advanced esophageal cancer requiring neoadjuvant therapy have significant dysphagia.

OBJECTIVE

To report our experience in using a fully covered self-expandable metal stent (FCSEMS) to treat malignant dysphagia and for maintenance of nutritional support during neoadjuvant therapy.

DESIGN

Retrospective study.

SETTING

Two tertiary-care referral centers.

PATIENTS

This study involved 55 patients with locally advanced esophageal cancer (50 adenocarcinoma, 5 squamous cell carcinoma). Forty-three patients were men, and the mean age was 65.8 years.

INTERVENTION

EUS followed by FCSEMS placement.

MAIN OUTCOME MEASUREMENTS

Procedural success, dysphagia scores, patient weights, stent migration, and stent-related complications.

RESULTS

All stents were successfully placed. Tumors were located in the middle esophagus (n = 10) and distal esophagus (n = 45). The mean dysphagia score obtained at 1 week after stent placement had improved significantly from baseline (2.4 and 1, respectively; P < .001). Patients maintained their weights at 1 month follow-up when compared with baseline (153 and 149 pounds, respectively; P = .58). Immediate complications included chest discomfort in 13 patients; 2 patients required stent removal because of intractable pain. One patient had stent removal because of significant acid reflux. Stent migration occurred at some point in 17 of 55 patients (31%). There was a delayed perforation in 1 patient. Because of disease progression or the discovery of metastasis after neoadjuvant therapy, only 8 of 55 patients underwent curative surgery.

LIMITATIONS

Retrospective study.

CONCLUSION

Placement of FCSEMSs in patients with locally advanced esophageal cancer significantly improves dysphagia and allows for oral nutrition during neoadjuvant therapy. FCSEMSs appear to be effective for palliating dysphagia. Migration was not associated with injury or harm to the patient and usually represented a positive response to neoadjuvant therapy. Few patients undergoing stenting in this situation ultimately undergo surgery because of disease progression or poor operative candidacy.

Surgical strategies for management of the open abdomen

Since the mid-1990s the surgical community has seen a surge in the prevalence of open abdomens (OAs) reported in the surgical literature and in clinical practice. The OA has proven to be effective in decreasing mortality and immediate postoperative complications; however, it may come at the cost of delayed morbidity and the need for further surgical procedures. Indications for leaving the abdomen open have broadened to include damage control surgery, abdominal compartment syndrome, and abdominal sepsis. The surgical options for management of the OA are now more diverse and sophisticated, but there is a lack of prospective randomized controlled trials demonstrating the superiority of any particular method. Additionally, critical care strategies for optimization of the patient with an OA are still being developed. Review of the literature suggests a bimodal distribution of primary closure rates, with early closure dependent on postoperative intensive care management and delayed closure more affected by the choice of the temporary abdominal closure technique. Invariably, a small fraction of patients requiring OA management fail to have primary fascial closure and require some form of biologic fascial bridge with delayed ventral hernia repair in the future.

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): patient with polytrauma]

Patients with polytrauma can be viewed as paradigmatic of the critically-ill patient. These previously healthy patients undergo a life-threatening aggression leading to an organic response that is no different from that in other types of patients. The profile of trauma patients has changed and currently corresponds to patients who are somewhat older, with a higher body mass index and greater comorbidity. Severe injuries lead to intense metabolic stress, posing a risk of malnutrition. Therefore, early nutritional support, preferentially through the enteral route, with appropriate protein intake and glutamine supplementation, provides advantages over other routes and types of nutritional formula. To avoid overnutrition, reduced daily calorie intake can be considered in obese patients and in those with medullary lesions. However, little information on this topic is available in patients with medullary lesions.

Parenteral nutrition suppresses the bactericidal response of the small intestine

BACKGROUND

Parenteral nutrition (PN) increases infectious risk in critically ill patients compared with enteral feeding. Previously, we demonstrated that PN feeding suppresses the concentration of the Paneth cell antimicrobial protein secretory phospholipase A2 (sPLA2) in the gut lumen. sPLA2 and other Paneth cell proteins are released in response to bacterial components, such as lipopolysaccharide (LPS), and they modulate the intestinal microbiome. Because the Paneth cell protein sPLA2 was suppressed with PN feeding, we hypothesized PN would diminish the responsiveness of the small bowel to LPS through reduced secretions and as a result exhibit less bactericidal activity.

METHODS

The distal ileum was harvested from Institute of Cancer Research mice, washed, and randomized for incubation with LPS (0, 1, or 10 μg/mL). Culture supernatant was collected and sPLA2 activity was measured. Bactericidal activity of the ileum segment secretions was assessed against Pseudomonas aeruginosa with and without an sPLA2 inhibitor at 2 concentrations, 100 nmol/L and 1 μmol/L. Institute of Cancer Research mice were randomized to chow or PN for 5 days. Tissue was collected for immunohistochemistry (IHC) and ileal segments were incubated with LPS (0 or 10 μg/mL). sPLA2 activity and bactericidal activity were measured in secretions from ileal segments.

RESULTS

Ileal segments responded to 10 μg/mL LPS with significantly greater sPLA2 activity and bactericidal activity. The bactericidal activity of secretions from LPS stimulated tissue was suppressed 50% and 70%, respectively, with the addition of the sPLA2-inhibitor. Chow displayed greater sPLA2 in the Paneth cell granules and secreted higher levels of sPLA2 than PN before and after LPS. Accordingly, media collected from chow was more bactericidal than PN. IHC confirmed a reduction in Paneth cell granules after PN.

CONCLUSION

This work demonstrates that ileal segments secrete bactericidal secretions after LPS exposure and the inhibition of the Paneth cell antimicrobial protein sPLA2 significantly diminishes this. PN feeding resulted in suppressed secretion of the sPLA2 and resulted in increased bacterial survival. This demonstrates that PN significantly impairs the innate immune response by suppressing Paneth cell function.

Nutrition and the open abdomen

Adequate nutrition support is critical in the management of patients with an open abdomen. Despite the literature supporting its use in trauma patients, provider concerns and clinical controversies remain regarding the early administration and long-term sequelae of enteral nutrition (EN) therapy in these patients. The purpose of this article is to review the clinical concepts behind the use of the open abdomen, as well as examine the altered nutrition requirements associated with the maintenance of a temporary laparostomy. The rationale for early EN is described, as well as the pros and cons surrounding the use of supplemental parenteral nutrition in those patients unable to meet nutrition goals enterally in a reasonable time frame. Finally, an open abdomen nutrition support algorithm is provided as part of the critical care plan in these patients who represent the sickest of surgical patients.

Optimal timing for the initiation of enteral and parenteral nutrition in critical medical and surgical conditions

The early provision of nutrients as part of specialized therapy for critically ill patients admitted for critical medical and surgical conditions is recommended by various international guidelines. Enteral nutrition is the first option and should be initiated 24-48 h after admission to an intensive care unit. Even after gastrointestinal anastomosis, early oral or enteral feeding is not only safe but also associated with enhanced recovery and fewer complications. Recent studies showed that the use of an enteral diet or parenteral nutrition that contains immune nutrients enhances the recovery of critically ill patients. Although the precise caloric target remains controversial, the general consensus advocates the avoidance of prolonged hypocaloric or hypercaloric feeding. However, there is still debate about the timing of the initiation of parenteral nutrition when enteral nutrition either is impossible or does not meet the nutritional goals. Although controversy remains, two recent studies showed that when enteral feeding is not feasible the early initiation of parenteral nutrition was not associated with palpable benefit.

Early enteral nutrition improves outcomes of open abdomen in gastrointestinal fistula patients complicated with severe sepsis

BACKGROUND

Although nutrition therapy is favorably considered as an assistant therapeutic measure in critical illness, little data evaluate its role in gastrointestinal fistula patients with severe sepsis after an open abdomen. The purpose of this study is to evaluate the role of early nutrition therapy in that population.

METHODS

This is a retrospective review of patients who underwent open abdomen management for gastrointestinal fistula and severe sepsis from January 2001 to June 2009. Nutrition therapy, fistula, abdominal closure, and demographics were noted. Succus entericus reinfusion (SER) was performed for high-output volume or multiple fistulae. Patients were divided into two groups based on whether enteral nutrition (EN) was initiated within 14 days after admission. Delivery route of nutrients, mortality, complications, and time to abdominal closure were compared among groups.

RESULTS

Eighty-two patients were included. Fifty-six (68.3%) patients survived to discharge. Forty-one (50%) patients received SER. EN was initiated within 14 days in 36 patients, with a mean initiation time at 8.3 ± 3.4 days; 46 patients did not start any EN within 14 days (29.9 ± 20.9 days). The mean age, BMI, APACHE II score, and fistula characteristics were similar between groups. The abdominal closure was accomplished more rapidly in patients fed within 14 days (142.8 vs 184.5 days, P = .017), with decreased mortality (11.1% vs 47.8%, P < .001).

CONCLUSIONS

Nutrition therapy plays an important role in the management of gastrointestinal fistula with severe sepsis. Early EN could be successfully delivered for that population, with improved mortality risk.

Route and type of nutrition and surgical stress influence secretory phospholipase A2 secretion of the murine small intestine

BACKGROUND

The function of secretory phospholipase A2 (sPLA2) is site dependent. In tissue, sPLA2 regulates eicosanoid production; in circulation, sPLA2 primes neutrophils; and in the intestinal lumen, sPLA2 provides innate bactericidal immunity as a defensin-related protein. Since parenteral nutrition (PN) primes leukocytes while suppressing intraluminal mucosal immunity, the authors hypothesized that (1) PN would diminish luminal sPLA2 activity but increase activity in intestinal tissue and serum and (2) stress would accentuate these changes.

METHODS

Mice received chow, a complex enteral diet (CED), intragastric PN (IG-PN), or PN in experiment 1 and chow, chow+stress, PN, or PN+stress in experiment 2.

RESULTS

In experiment 1, luminal sPLA2 activity was greatest in chow and decreased in CED, IG-PN, and PN, with PN lower than CED and IG-PN. Compared to that after chow, serum sPLA2 activity dropped after CED, IG-PN, and PN. Serum sPLA2 was higher in portal than systemic serum. In experiment 2, PN lowered luminal sPLA2 activity vs chow. Stress lowered luminal sPLA2 activity in chow, without change in PN. Following stress, luminal immunoglobulin A increased in chow but not PN. Serum sPLA2 activity increased in PN.

CONCLUSIONS

PN attenuates sPLA2 activity in intestinal fluid, consistent with suppressed innate mucosal defense. Stress suppresses luminal fluid sPLA2 activity in chow but not the immunoglobulin A response; PN impairs both. Stress significantly elevates serum sPLA2 in PN-fed mice, consistent with known increased neutrophil priming with PN. PN reduces innate bactericidal immunity of the gut but upregulates serum proinflammatory products poststress.

Safe management of anastomotic leakage after gastric cancer surgery with enteral nutrition via a nasointestinal tube

PURPOSE

Anastomotic leakage is a serious complication after gastric cancer surgery. Despite the superiority of enteral nutrition (EN), total parenteral nutrition (PN) remains the standard therapy for anastomotic leakage. After introduction of EN via a nasointestinal tube for patients with anastomotic leakage in our institution in 2006, standard nutritional therapy was shifted gradually from PN to EN. The present preliminary study evaluates the safety and feasibility of EN via a nasointestinal tube for anastomotic leakage after gastric cancer surgery.

METHODS

Retrospective review of all gastric cancer surgeries from 2005 to 2009 (n = 2,588) revealed 53 patients (2.0%) who developed anastomotic leakage and were treated conservatively. EN was performed via a nasointestinal tube inserted using a guidewire under X-ray fluoroscopy. Clinical outcomes and complications following EN were compared with those in patients treated with PN (historical control group). The severity of complications was evaluated according to the Clavien-Dindo classification.

RESULTS

Fifty patients were included in the final analysis (three patients died): 29 patients managed by EN and 21 managed by PN. There were no significant differences in clinical outcomes and the frequency of total complications between the two groups; however, there were fewer tube/catheter-related complications in the EN compared with the PN group (1 vs. 7, respectively; P < 0.01). There was one epistaxis (3.4%; grade I) in the EN group and seven catheter infections (33.3%; grade II) in the PN group. The risk of grade II or higher complications was greater in the PN than the EN group (11 vs. 4, respectively; P < 0.01), with the greatest difference seen in the incidence of catheter infections. On days 7, 10, and 15 after diagnosis of leakage, the white blood cell count and C-reactive protein levels were higher in the PN than in the EN group. The PN group required prolonged intravenous antibiotic infusion (P < 0.01).

CONCLUSIONS

Nasointestinal tube insertion with EN can be performed safely for patients with anastomotic leakage. A major advantage of EN is fewer infectious complications. Because EN was not inferior to PN in terms of clinical outcome, we recommended that it is used in patients with anastomotic leakage after gastric cancer surgery.

Early enteral nutrition reduces the rate of life-threatening complications after thoracic esophagectomy in patients with esophageal cancer

BACKGROUND

Early postoperative enteral nutrition has been suggested to improve the nutritional status of patients after esophageal surgery. However, whether enteral nutrition decreases rates of surgical complications and increases the completion rate of the clinical management pathway is unclear.

METHODS

We analyzed 154 patients who were randomly assigned to either an enteral or parenteral nutrition group after undergoing esophagectomy, compared the incidence of surgical complications, and evaluated the completion rate of the clinical pathway. In these 2 patient groups, perioperative management was performed through identical clinical pathways, except for nutrition.

RESULTS

The overall rate of surgical complications of any type did not differ between patients who received early enteral nutrition and those who did not (p = 0.50); however, the rate of life-threatening surgical complications was significantly lower in patients who received early enteral nutrition (p = 0.02). The rate of non-life-threatening surgical complications did not differ between the groups (p = 0.98). In patients who received enteral nutrition, the completion rate of the clinical pathway was higher (p = 0.03), and the postoperative hospital stay was shorter (p = 0.04).

CONCLUSIONS

Early enteral nutrition reduces the incidence of life-threatening surgical complications and improves the completion rate of the clinical pathway for thoracic esophagectomy.