Total enteral nutrition as prophylactic therapy for pancreatic necrosis infection in severe acute pancreatitis

Enteral nutrition is associated with high rates of pneumonia in intensive care unit (ICU) patients with acute pancreatitis

PURPOSE

Enteral nutrition is associated with improved outcomes in acute pancreatitis (AP), but previous studies have not focused on critically-ill patients. Our purpose was to determine the association between nutritional support and infectious complications in ICU-admitted patients with AP.

METHODS

A retrospective analysis of patients with AP admitted in ICUs of 127 US hospitals from the eICU Collaborative were included. Patients were classified by type (initial and any use) of nutritional support they received: none (NN); oral (ON); enteral (EN); and parenteral nutrition (PN).

RESULTS

925 patients were identified. Length of stay was longer in the initial PN group (PN 21.3 ± 15.4 d, EN 19.1 ± 20.1 d, ON 8 ± 7.1 d, NN 6.6 ± 6.3 d, p < 0.001) and mortality was more common in the initial EN group (EN 16.7%, PN 8.9%, ON 2.7%, NN 10.9%, p < 0.001). Multivariate analysis found any EN use to be associated with infections (OR 2.12, 95% CI: 1.13-3.98, p = 0.019) and pneumonias (OR 2.04, 95% CI: 1.04-4.03, p = 0.039).

CONCLUSION

EN was associated with an increased risk for pneumonias and overall infections in critically-ill patients with AP. More studies are needed to assess optimal nutritional approaches in critically-ill AP patients and patients who do not tolerate EN.

Mortality and overall and specific infection complication rates in patients who receive parenteral nutrition: systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Parenteral nutrition (PN) is an available option for nutritional therapy and is often required in the hospital setting to overcome malnutrition.

OBJECTIVES

The aim of this study was to assess whether PN is associated with an increased risk of mortality or infectious complications in all groups of hospitalized patients compared with those receiving other nutritional support strategies.

METHODS

For this systematic review and meta-analysis MEDLINE, Embase, Cochrane Central, Scopus, clinicaltrials.gov, and Web of Science were searched for randomized controlled trials (RCTs) and observational studies with parallel groups that explored the effect of PN on mortality and infectious complications, published until March 2021. Two independent reviewers extracted the data and assessed the risk of bias. Fixed-effects meta-analysis was performed to compare the groups from RCTs. Trial sequential analysis (TSA) was used to identify whether the results were sufficient to reach definitive conclusions.

RESULTS

Of the 83 included studies that compared patients receiving PN with those receiving other strategies, 67 RCTs were included in the meta-analysis. PN was not associated with a higher risk of mortality (RR: 1.01; 95% CI: 0.95, 1.07). On the other hand, PN was associated with a higher risk of infectious events (RR: 1.23; 95% CI: 1.12, 1.36). PN was specifically associated with abdominal infection and catheter infection. The TSA showed that there were sufficient data to make numerical conclusions about mortality, any infectious event, and abdominal infectious complications.

CONCLUSIONS

This study suggests that although PN is not associated with greater mortality in hospitalized patients, it is associated with infectious complications. Through TSA, definite conclusions about survival and infection rates could be made.This review was registered at www.crd.york.ac.uk/prospero/ as CRD42018075599.

Early Enteral Nutrition Prevent Acute Pancreatitis From Deteriorating in Obese Patients

GOALS

The aim of this study was to determine a potential strategy to prevent acute pancreatitis (AP) from deteriorating in obese patients.

BACKGROUND

Nutritional support plays a critical role in the treatment of AP. Early enteral nutrition (EEN) is considered to be able to protect mucosa of AP patients and alleviate inflammatory reactions. Obesity worsen AP prognosis. However, little is known about the effects of EEN in obese patients.

STUDY

Prospective randomized control trial. Subjects with moderately severe AP or severe AP were divided into the visceral fat obesity (VFO) group and the non-VFO group by obesity index VFO. The patients received "delayed" enteral nutrition (started enteral nutrition feeding after the first 48 hours after admission to the hospital: group A: patients of non-VFO, n=108; group B: VFO patients, n=88) or EEN (in the VFO subgroup, group C: n=91).Occurrence of complication, clinical outcomes, plasma levels of cytokines, and intestine gut barrier index were measured at different timepoints after admission.

RESULTS

VFO was a risk factor for aggravating of AP. EEN prevented the VFO patients from developing pancreatic necrotic infection, the mechanism of which might be related with inhibiting excessive inflammatory reactions, adjusting the imbalance of inflammatory response, and alleviating ischemia of intestine mucosa.

CONCLUSIONS

The potential strategy, EEN, was able to prevent AP from deteriorating in obese patients.

Meta-Analysis of Early Nutrition: The Benefits of Enteral Feeding Compared to a Nil Per Os Diet Not Only in Severe, but Also in Mild and Moderate Acute Pancreatitis

The recently published guidelines for acute pancreatitis (AP) suggest that enteral nutrition (EN) should be the primary therapy in patients suffering from severe acute pancreatitis (SAP); however, none of the guidelines have recommendations on mild and moderate AP (MAP). A meta-analysis was performed using the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P). The following PICO (problem, intervention, comparison, outcome) was applied: P: nutrition in AP; I: enteral nutrition (EN); C: nil per os diet (NPO); and O: outcome. There were 717 articles found in Embase, 831 in PubMed, and 10 in the Cochrane database. Altogether, seven SAP and six MAP articles were suitable for analyses. In SAP, forest plots were used to illustrate three primary endpoints (mortality, multiorgan failure, and intervention). In MAP, 14 additional secondary endpoints were analyzed (such as CRP (C-reactive protein), WCC (white cell count), complications, etc.). After pooling the data, the Mann-Whitney U test was used to detect significant differences. Funnel plots were created for testing heterogeneity. All of the primary endpoints investigated showed that EN is beneficial vs. NPO in SAP. In MAP, all of the six articles found merit in EN. Analyses of the primary endpoints did not show significant differences between the groups; however, analyzing the 17 endpoints together showed a significant difference in favor of EN vs. NPO. EN is beneficial compared to a nil per os diet not only in severe, but also in mild and moderate AP.

Early nasojejunal tube feeding versus nil-by-mouth in acute pancreatitis: A randomized clinical trial

BACKGROUND/OBJECTIVES

There is substantial evidence of superiority of enteral nutrition (EN) to parenteral nutrition in acute pancreatitis (AP) treatment, but few studies evaluated its effectiveness compared to no intervention. The objective of our trial was to compare the effects of EN to a nil-by-mouth (NBM) regimen in patients with AP.

METHODS

Patients with AP were randomized to receive either EN via a nasojejunal tube initiated within 24 h of admission or no nutritional support. Systemic inflammatory response syndrome (SIRS) was assessed as the primary outcome. Secondary outcomes included mortality, organ failure, local complications, infected pancreatic necrosis, surgical interventions, length of hospital stay, adverse events and inflammatory response intensity. Outcomes were compared using Student's t-test and Mann-Whitney U test as appropriate.

RESULTS

214 patients were randomized in total, 107 to each group. SIRS occurrence was similar between groups, with 48 (45%) versus 51 (48%), respectively (RR 0.94; 95% CI 0.71-1.26). No significant reduction of persistent organ failure (RR 0.81; 95% CI 0.52-1.27) and mortality (RR 0.59; 95% CI 0.28-1.23) was present in the EN group. There were no significant differences in other outcomes between the groups. When analyzing the occurrence of SIRS and mortality in subgroup of patients with severe disease no significant differences were noted.

CONCLUSION

Our results showed no significant reduction of persistent organ failure and mortality in patients with AP receiving early EN compared to patients treated with no nutritional support (NCT01965873).

Enteral nutrition in acute pancreatitis: A review of the current evidence

The use of enteral feeding as part of the management of acute pancreatitis dates back almost two decades. This review describes the indications for and limitations of enteral feeding for the treatment of acute pancreatitis using up-to-date evidence-based data. A systematic review was carried out to analyse current data on the use of enteral nutrition in the management of acute pancreatitis. Relevant literature was analysed from the viewpoints of enteral vs parenteral feeding, early vs delayed enteral nutrition, nasogastric vs nasojejunal feeding, and early oral diet and immunonutrition, particularly glutamine and probiotic supplementation. Finally, current applicable guidelines and the effects of these guidelines on clinical practice are discussed. The latest meta-analyses suggest that enteral nutrition significantly reduces the mortality rate of severe acute pancreatitis compared to parenteral feeding. To maintain gut barrier function and prevent early bacterial translocation, enteral feeding should be commenced within the first 24 h of hospital admission. Also, the safety of nasogastric feeding, which eases the administration of enteral nutrients in the clinical setting, is likely equal to nasojejunal feeding. Furthermore, an early low-fat oral diet is potentially beneficial in patients with mild pancreatitis. Despite the initial encouraging results, the current evidence does not support the use of immunoenhanced nutrients or probiotics in patients with acute pancreatitis.

Potential influence of intravenous lipids on the outcomes of acute pancreatitis

Parenteral nutrition (PN) has been associated with a higher rate of adverse outcomes compared with enteral feeding in patients with acute pancreatitis (AP). However, PN may be necessary when feeding via the enteral route is poorly tolerated or impossible, and PN is recommended as a second-line nutrition therapy in AP. Intravenous (IV) lipids are commonly used as a part of PN in patients with AP. While the adverse outcomes related to the use of PN in AP have commonly been attributed to infectious complications, data suggest that the unsaturated fatty acids in the triglycerides used in IV lipids may contribute to the development of organ failure. We discuss the clinical and experimental data on this issue and the alternative lipid emulsions that are being studied.

Early enteral nutrition is superior to delayed enteral nutrition for the prevention of infected necrosis and mortality in acute pancreatitis

OBJECTIVES

The exact time of initiation of total enteral nutrition (TEN) in severe acute pancreatitis (SAP) and its influence on the disease outcome are not well known.

METHODS

An analysis of 197 cases with predicted SAP allocated to: group A (n = 97), early TEN (started within the first 48 hours after admission to hospital); and group B (n = 100), delayed TEN (started after 48 hours).

RESULTS

Infection of necrosis/fluid collections occurred in 4 patients in group A and 18 patients in group B (P < 0.05). Respiratory failure and transfer to intensive care unit occurred more frequently in group B than in group A (15 vs 5 and 15 vs 3 patients; P < 0.05). Multiple-organ failure was observed in 9 patients in group A and 16 patients in group B (P > 0.05). Seven patients in group A and 11 patients in group B underwent surgery (P > 0.05). All 9 reported deaths occurred in group B (P < 0.05). The time to start TEN was a predictor of infected necrosis/fluid collection (odds ratio, 4.09; P = 0.028).

CONCLUSIONS

Delayed compared to early TEN is associated with higher mortality, increased frequency of infected necrosis/fluid collections, respiratory failure, and a need for intensive care unit hospitalization. Enteral nutrition in SAP should be started within 48 hours after admission to hospital.

[Intravenous glutamine and early nasojejunal nutrition in severe acute pancreatitis -- a prospective randomized clinical study]

INTRODUCTION

Severe acute pancreatitis (SAP) is still one of the great challenges in gastro-intestinal surgery. According to recent studies, intravenously administered glutamine with total parenteral nutrition may be beneficial in the prevention of infectious complications and may reduce mortality rate. However, it has not been investigated yet, whether i.v. glutamine is able to achieve the same effect with early enteral nutrition as well.

OBJECTIVES

The objective of our prospective randomized double-blind study was to explore the effects of intravenously administered glutamine with early nasojejunal nutrition in severe acute pancreatitis.

PATIENTS AND METHODS

Forty-five patients with severe acute pancreatitis (with a Glasgow score at least 3 and/or a CRP level above 150 mg/ml on admission) were randomized into two groups. Group Glutamine (n = 24) was given 0.5 g/kg/die glutamine intravenously, while the control group (n = 21) received normal amino acid solution in the same quantity for 7 days. Nasojejunal nutrition was introduced 48 hours after admission in case of all patients, and their management was the same in every other aspect, too. The primary end-points of the study were the rate of pancreas-specific infectious complications and organ failure, and the secondary end-points were the necessity for radiological and surgical interventions, length of hospital stay and mortality rate.

RESULTS

In group Glutamine, infected acute peripancreatic fluid collections (APFC) were detected in 4 patients, 2 patients had post-necrotic pancreatic/peripancreatic fluid collections (PNPFC), 2 patients had infected pseudocysts and 2 patients had walled-off pancreatic necrosis (WOPN). Ten patients were cured by ultrasound assisted puncture or drainage successfully. No surgical intervention was necessary. In the control group, 4 patients had infected APFC, 2 patients had infected PNPFC, infected pseudocysts and infected WOPN were diagnosed in 3 cases. Radiological intervention was effective in 9 cases, but 3 patients needed surgery. Three patients died of multi-organ failure, thus the mortality rate of the control group was 14%, while the mortality rate of the Glutamine group was zero. The mean hospital stay of the Glutamine group was 10.6 days, which is significantly shorter than the mean hospital stay of the control group, which was 15.9 days (p = 0.00104).

DISCUSSION

The results of the Glutamine group are better in every end-points, however, statistically significant difference was detected in one parameter only, the length of hospital stay.

Serum inter-cellular adhesion molecule 1 is an early marker of diagnosis and prediction of severe acute pancreatitis

AIM: To determine if serum inter-cellular adhesion molecule 1 (ICAM-1) is an early marker of the diagnosis and prediction of severe acute pancreatitis (SAP) within 24 h of onset of pain, and to compare the sensitivity, specificity and prognostic value of this test with those of acute physiology and chronic health evaluation (APACHE) II score and interleukin-6 (IL-6).

METHODS: Patients with acute pancreatitis (AP) were divided into two groups according to the Ranson’s criteria: mild acute pancreatitis (MAP) group and SAP group. Serum ICAM-1, APACHE IIand IL-6 levels were detected in all the patients. The sensitivity, specificity and prognostic value of the ICAM-1, APACHE IIscore and IL-6 were evaluated.

RESULTS: The ICAM-1 level in 36 patients with SAP within 24 h of onset of pain was increased and was significantly higher than that in the 50 patients with MAP and the 15 healthy volunteers (P < 0.01). The ICAM-1 level (25 ng/mL) was chosen as the optimum cutoff to distinguish SAP from MAP, and the sensitivity, specificity, positive predictive value, negative predictive value (NPV), positive likelihood ratio and negative likelihood ratio were 61.11%, 71.42%, 0.6111, 0.7142, 2.1382 and 0.5445, respectively. The area under the curve demonstrated that the prognostic accuracy of ICAM-1 (0.712) was similar to the APACHE-IIscoring system (0.770) and superior to IL-6 (0.508) in distinguishing SAP from MAP.

CONCLUSION: ICAM-1 test is a simple, rapid and reliable method in clinical practice. It is an early marker of diagnosis and prediction of SAP within the first 24 h after onset of pain or on admission. As it has a relatively low NPV and does not allow it to be a stand-alone test for the diagnosis of AP, other conventional diagnostic tests are required.

Current trends in critical care nutrition

Nutrition in the intensive care setting is a vital part of patient care, and may even be referred to as "nutritional therapy". Current nutritional practices have progressed a lot over the past few years, and draw from a large body of accumulating evidence. Yet, as with other trends in critical care, there are a lot of variations in the way nutrition is approached between institutions, as well as between individual physicians. This review attempts to look at some of these differences and provide recommendations based upon the available literature.

A meta-analysis of enteral nutrition and total parenteral nutrition in patients with acute pancreatitis

Objective. To analyze the effect of total parenteral nutrition (TPN) and enteral nutrition (EN) in patients with acute pancreatitis. Methods. Randomized controlled trials of TPN and EN in patients with acute pancreatitis were searched in NCBI and CBM databases and The Cochrane Controlled Trials Register. Six studies were enrolled into the analysis, and the details about the trial designs, characters of the subjects, results of the studies were reviewed by two independent authors and analyzed by STATA 11.0 software. Results. Compared with TPN, EN was associated with a significantly lower incidence of pancreatic infection complications (RR = 0.556, 95% CI 0.436∼0.709, P = .000), MOF (RR = 0.395, 95% CI 0.272∼0.573, P = .003), surgical interventions (RR = 0.556, 95% CI 0.436∼0.709, P = .000), and mortality (RR = 0.426, 95% CI 0.238∼0.764, P = .167). There was no statistic significance in non-pancreatitis-related complications (RR = 0.853, 95% CI 0.490∼1.483, P = .017). However, EN had a significantly higher incidence of non-infection-related complications (RR = 2.697, 95% CI 1.947∼3.735, P = .994). Conclusion. EN could be the preferred nutrition feeding method in patients with acute pancreatitis.

A clinical and economic evaluation of enteral nutrition

MOTIVATION

The American Society of Parenteral and Enteral Nutrition (ASPEN) guidelines advise use of enteral nutrition (EN) for critically ill hospital patients requiring nutritional support, but no studies have comprehensively estimated economic benefits from adherence to this recommendation.

METHODS

We systematically reviewed studies comparing EN to alternative nutritional support therapies among adult, critically ill patients. We reviewed 1200 abstracts, selected 243 for further review, and included 48 studies in our analysis. Most retained studies compared EN and parenteral nutrition (PN). Using meta-analysis, we estimated the absolute impact of EN on adverse event risk and its impact on treatment duration and length of stay. These estimates were converted to population economic impacts by assuming 10% of PN patients are suitable candidates for EN.

RESULTS

Compared to PN, EN reduces the risk of major, potentially life-threatening infections (RR = 0.58, 95% confidence interval [CI] 0.44 to 0.77), the risk of major, potentially life-threatening non-infection events (RR = 0.73, CI 0.59 to 0.91), and suggests a reduction in mortality, although this result did not achieve statistical significance (RR = 0.70, CI 0.45 to 1.09). EN also reduces inpatient length of stay, time in the ICU, and length of nutritional treatment. Compared to PN, EN savings from reduced adverse event risks average nearly $1500 per patient; savings from reduced hospital length of stay amount to nearly $2500 per patient. Shifting 10% of parenterally treated adult patients in the U.S. to EN would save $35 million annually due to reduced adverse events and another $57 million due to shorter hospital stays.

CONCLUSION

The evidence of both clinical and economic gains from EN is consistent with ASPEN guidelines recommending use of EN in critically ill hospital patients when possible.

Pancreatite necro-hemorrágica: atualização e momento de operar

INTRODUÇÃO: A pancreatite necro-hemorrágica representa a variante mais grave do espectro de apresentações clínicas que podem compor o quadro da pancreatite aguda. Embora já conhecida há muitos séculos, inúmeras questões permanecem em aberto acerca dessa entidade e o número de trabalhos sobre o assunto publicados nos últimos anos tem sido muito expressivo. MÉTODO: Foi realizada ampla pesquisa na literatura, com especial atenção aos artigos publicados nos últimos três anos e indexados ao PubMed. Foram utilizados os seguintes descritores de forma cruzada: pancreatitis, surgical procedures; necrosis. A pesquisa inicial evidenciou cerca de 13.000 artigos, sendo avaliados os mais relevantes dos últimos três anos além de artigos mais antigos, considerados "clássicos" sobre o assunto e que, portanto, não poderiam deixar de ser citados. CONCLUSÃO: O tratamento da pancreatite aguda envolve um grande número de questões, dentre as quais as mais importantes estão relacionadas ao manejo da antibioticoterapia, tipo de dieta empregada e as questões relacionadas ao manejo da necrose infectada. Em especial, mudanças radicais foram implementadas nos últimos anos sobre todos esses tópicos, e uma atualização constante deve ser obrigatoriamente buscada pelos profissionais envolvidos no tratamento dessa doença.

Evidence-based use of enteral nutrition in acute pancreatitis

PURPOSE

A systematic review was carried out to analyze current evidence-based data on the use of enteral nutrition in the management of acute pancreatitis.

METHODS

Literature search was performed on "Pubmed" and "Medline" databases to identify articles investigating the role and potential effect of enteral nutrition on the outcome of patients with acute pancreatitis. Relevant data were analyzed from the viewpoints of possible benefits and complications, route and timing of administration, and composition of nutrients.

RESULTS

Thirty-two prospective randomized controlled trials and 15 meta-analyses of those were identified and included in this overview. Strong evidence suggests that enteral nutrition significantly reduces mortality rate of severe acute pancreatitis. While both nasogastric and nasojejunal feeding appear to be safe in severe pancreatitis, early low-fat oral diet is possibly beneficial in patients with mild pancreatitis. Since maintenance of the gut barrier function is one of the crucial effects of enteral nutrition, enteral feeding should be commenced within the first 24 h after hospital admission, in order to prevent early bacterial translocation. However, it seems that neither immunonoenhanced nutrients nor probiotic supplementation are able to reduce mortality further, and--therefore--cannot be recommended for patients with acute pancreatitis.

CONCLUSION

Although enteral nutrition is undoubtedly a key component of the management of acute pancreatitis, the exact role of that is needed to be defined yet. In particular, conflicting data from studies on nutrient compositions will require further clarification in the future.

Nutritional strategies in severe acute pancreatitis: a systematic review of the evidence

Nutrition in severe acute pancreatitis is a critical aspect in the management of this condition. This review aims to systematically review the evidence available to inform the use of nutritional support in severe acute pancreatitis. High quality (level 1) evidence supports naso-jejunal enteral nutrition (NJ-EN) over parenteral nutrition (PN) reducing infectious morbidity and showing a trend towards reduced organ failure although there is no detectable difference in mortality. Trial data may underestimate benefit as patients are often recruited with predicted rather than proven severe disease. NJ-EN is safe when started immediately (level 3 evidence). NJ-EN is often impractical and naso-gastric (NG) feeding seems to be equivalent in terms of safety and outcomes whilst being more practical (level 2 evidence). Regarding feed supplementation, probiotic feed supplementation is not beneficial (level 1 evidence) the and may cause harm with excess mortality (level 2 evidence). No evidence exists to confirm benefit of the addition of prokinetics in severe acute pancreatitis (SAP) although their use is proven in other critically ill patients. Level 2 evidence does not currently support the use of combination immuno-nutrition though further work on individual agents may provide differing results. Level 2 evidence does not support intravenous supplementation of anti-oxidants and has demonstrated that these too may cause harm.

Enteral versus parenteral nutrition for acute pancreatitis

BACKGROUND

Acute pancreatitis creates a catabolic stress state promoting a systemic inflammatory response and nutritional deterioration. Adequate supply of nutrients plays an important role in recovery. Total parenteral nutrition (TPN) has been standard practice for providing exogenous nutrients to patients with severe acute pancreatitis. However, recent data suggest that enteral nutrition (EN) is not only feasible, but safer and more effective.Therefore, we sought to update our systematic review to re-evaluate the level of evidence.

OBJECTIVES

To compare the effect of TPN versus EN on mortality, morbidity and length of hospital stay in patients with acute pancreatitis.

SEARCH STRATEGY

Trials were identified by computerized searches of The Cochrane Controlled Trials Register, MEDLINE, and EMBASE. Additional studies were identified by searching Scisearch, bibliographies of review articles and identified trials. The search was undertaken in August 2000 and updated in September 2002, October 2003, November 2004 and November 2008. No language restrictions were applied.

SELECTION CRITERIA

Randomized clinical trials comparing TPN to EN in patients with acute pancreatitis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. A standardized form was used to extract relevant data.

MAIN RESULTS

Eight trials with a total of 348 participants were included. Comparing EN to TPN for acute pancreatitis, the relative risk (RR) for death was 0.50 (95% CI 0.28 to 0.91), for multiple organ failure (MOF) was 0.55 (95% CI 0.37 to 0.81), for systemic infection was 0.39 (95% CI 0.23 to 0.65), for operative interventions was 0.44 (95% CI 0.29 to 0.67), for local septic complications was 0.74 (95% CI 0.40 to 1.35), and for other local complications was 0.70 (95% CI 0.43 to 1.13). Mean length of hospital stay was reduced by 2.37 days in EN vs TPN groups (95% CI -7.18 to 2.44). Furthermore, a subgroup analysis for EN vs TPN in patients with severe acute pancreatitis showed a RR for death of 0.18 (95% CI 0.06 to 0.58) and a RR for MOF of 0.46 (95% CI 0.16 to 1.29).

AUTHORS' CONCLUSIONS

In patients with acute pancreatitis, enteral nutrition significantly reduced mortality, multiple organ failure, systemic infections, and the need for operative interventions compared to those who received TPN. In addition, there was a trend towards a reduction in length of hospital stay. These data suggest that EN should be considered the standard of care for patients with acute pancreatitis requiring nutritional support.

Exocrine pancreatic involvement in critically ill patients

PURPOSE OF REVIEW

To learn about the prevalence, pathophysiology, and treatment of exocrine pancreatic involvement in critically ill patients.

RECENT FINDINGS

Elevations in the levels of pancreatic enzymes are observed in up to 80% of intensive care patients. Most of these patients do not develop clinically relevant pancreatitis. However, elevations in enzyme levels do represent pancreatic damage with a risk of complications. Different factors have been discussed, which may contribute to pancreatic damage in critically ill patients. These include splanchnic hypoperfusion during shock or major surgery, bacterial translocation, elevated triglyceride levels, development of biliary sluge, and biliary pancreatitis, as well as several drugs. Imaging procedures and inflammatory markers help to identify relevant disease. Several therapeutic options have been discussed recently with a focus on early enteral nutrition.

SUMMARY

Pancreatic damage is frequently observed in critically ill patients. Although in most of these patients, this is without major clinical consequences, some patients develop relevant pancreatitis, which contributes to morbidity and mortality. Risk factors have been identified and therapeutic strategies have been changed.

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.

Nutritional immunomodulation of acute pancreatitis

Despite the great advances in our understanding of the pathophysiology of acute pancreatitis, no specific therapy has emerged, and treatment remains supportive. In patients with the severe form of the disease, in which mortality remains high at 20% to 30%, the function of the upper gastrointestinal tract is disturbed due to extrinsic compression by the inflamed and swollen pancreas, and normal eating is impossible. Such patients often develop multiple organ failure, necessitating intensive-care management and artificial ventilation for weeks on end. In this setting, protein catabolism will rapidly result in protein deficiency and further complications unless nutritional support is commenced. Recent studies have shown that, despite the risk of disease exacerbation through pancreatic stimulation, enteral feeding is more effective than parenteral feeding in improving outcome. Experimental studies suggest that this can be attributed to its content of specific immunomodulating nutrients, such as glutamine, arginine, and n-3 fatty acids, and by its stabilizing effect on the gut flora through the provision of prebiotics. Further studies are indicated to examine whether dietary enrichment with these substrates, along with regulation of the gut bacteria with probiotics, can improve outcome further.

Nutrition support in severe acute pancreatitis

Nutritional support can improve the outcome from severe acute pancreatitis in two ways: first by providing the building blocks for tissue repair and recovery, and second, by modulating the inflammatory response and preventing organ failure, both of which are responsible for most of the morbidity and mortality associated with the disease. This review discusses the evidence on which these statements are based.

Management of severe acute pancreatitis: it's all about timing

PURPOSE OF REVIEW

This study provides an update on the treatment of severe acute pancreatitis (SAP) with emphasis on nutrition, infection-prophylaxis, biliary pancreatitis, surgical intervention and new randomized controlled trials.

RECENT FINDINGS

The most relevant new insights are: (i) early enteral nutrition in SAP is not only capable of reducing infectious complications but may also reduce mortality; (ii) there is increasing evidence that antibiotic-prophylaxis is not capable of preventing infectious complications in SAP; (iii) probiotic-prophylaxis is being considered as an alternative with promising experimental results; (iv) in biliary pancreatitis, early endoscopic retrograde cholangiography with sphincterotomy (within 48 h) is beneficial in case of ampullary obstruction, although it may be withheld in the event of negative endoscopic ultrasound; (v) surgical intervention for infected (peri-)pancreatic necrosis is increasingly being postponed; (vi) minimally invasive strategies are being considered as a full alternative for necrosectomy by laparotomy in infected (peri-)pancreatic necrosis; (vii) the Atlanta classification should no longer be used to describe computed tomography findings in acute pancreatitis; and (viii) only five randomized controlled trials of patients with acute pancreatitis are currently registered in the international trial registries.

SUMMARY

Timing of intervention is becoming increasingly important in SAP management.

Parenteral nutrition

PURPOSE OF REVIEW

The past 12 months have seen advances in the safe use of intravenous nutrition and its place in the therapeutic armamentarium.

RECENT FINDINGS

Complications of intravenous nutrition and proposed optimal strategies to avoid them are considered, with particular attention to the hazards of hyperglycaemia. Intravenous nutrition in certain specified conditions is addressed, including its minor role in advanced malignancy. New details on the effects of amended lipid emulsions are presented, together with a meta-analysis of growth hormone and glutamine.

SUMMARY

Parenteral nutrition needs attention to detail if it is to be employed safely and effectively. Special care should be taken to maintain blood glucose in the normal range. There are currently insufficient data to warrant wholesale switching to novel lipid emulsions or the global use of glutamine or growth hormone.

Enteral versus parenteral nutrition for acute pancreatitis

BACKGROUND

Acute pancreatitis creates a catabolic stress state promoting a systemic inflammatory response and nutritional deterioration. Adequate supply of nutrients plays an important role to ensure optimum recovery. Total parenteral nutrition (TPN) has been the standard practice for providing exogenous nutrients to patients with severe acute pancreatitis. However, recent data suggest that enteral nutrition (EN) is feasible. Thus, a comparison of EN and TPN in patients with acute pancreatitis needs to be made.

OBJECTIVES

To compare the effect of total parenteral nutrition (TPN) versus enteral nutrition (EN) on mortality, morbidity and length of hospital stay in patient with acute pancreatitis.

SEARCH STRATEGY

Trials were identified by computerized searches of The Cochrane Controlled Trials Register, MEDLINE, and EMBASE. Additional studies were identified and included where relevant by searching Scisearch, the bibliographies of review articles and identified trials, and personal files. The search was undertaken in August, 2000 and updated in September 2002. No language restrictions were applied.

SELECTION CRITERIA

Randomized clinical trials, in which nutrition support with TPN were compared to EN in patients with acute pancreatitis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. Information was collected on death, length of hospital stay, systemic infection, local septic complications, and other local complications.

MAIN RESULTS

Two trials with a total of 70 participants were included. The relative risk (RR) for death with EN vs TPN was 0.56 (95% CI 0.05 to 5.62). Mean length of hospital stay was reduced with EN (WMD -2.20, 95% CI -3.62 to -0.78). RR for systemic infection with EN vs TPN was 0.61 (95% CI 0.29 to 1.28). In one trial, RR for local septic complications and other local complications with EN vs TPN was 0.56 (95% CI 0.12 to 2.68) and 0.16 (95% CI 0.01 to 2.86) respectively.

REVIEWER'S CONCLUSIONS

Although there is a trend towards reductions in the adverse outcomes of acute pancreatitis after administration of EN, clearly there are insufficient data to draw firm conclusions about the effectiveness and safety of EN versus TPN. Further trials are required with sufficient size to account for clinical heterogeneity and to measure all relevant outcomes.