Enteral nutrition within 48 hours of admission improves clinical outcomes of acute pancreatitis by reducing complications: a meta-analysis

Severe Acute Pancreatitis and Necrotizing Pancreatitis

Acute pancreatitis results in nearly 250,000 admissions annually. Acute pancreatitis varies widely in its clinical presentation. Pancreatic necrosis accounts for substantial additional morbidity, with mortality rates remaining as high as 10% to 20% despite advances in critical care. The extent of necrosis correlates well with the incidence of infected necrosis, multiorgan failure, need for pancreatic debridement, and morbidity and mortality. Having established the diagnosis of pancreatic necrosis, goals of appropriately aggressive resuscitation should be established and adhered to in a multidisciplinary approach involving both medical and surgical critical care.

Current concepts in the management of acute pancreatitis

Guidelines for the management of acute pancreatitis (AP) are based on the Western experience, which may be difficult to extrapolate in India due to socioeconomic constraints. Hence, modifications based on the available resources and referral patterns should be introduced so as to ensure appropriate care. We reviewed the current literature on the management of AP available in English on Medline and proposed guidelines locally applicable. Patients of AP presenting with systemic inflammatory response syndrome are at risk of moderate-severe pancreatitis and hence, should be referred to a tertiary center early. The vast majority of patients with AP have mild disease and can be managed at smaller centers. Early aggressive fluid resuscitation with controlled fluid expansion, early enteral nutrition, and culture-directed antibiotics improve outcomes in AP. Infected pancreatic necrosis should be managed in a tertiary care hospital within a multidisciplinary setup. The "step up" approach involving antibiotics, percutaneous drainage, and minimally invasive necrosectomy instituted sequentially based on clinical response has improved the outcomes in this subgroup of patients.

Consensus guidelines on severe acute pancreatitis

This Position Paper contains clinically oriented guidelines by the Italian Association for the Study of the Pancreas (AISP) for the diagnosis and treatment of severe acute pancreatitis. The statements were formulated by three working groups of experts who searched and analysed the most recent literature; a consensus process was then performed using a modified Delphi procedure. The statements provide recommendations on the most appropriate definition of the complications of severe acute pancreatitis, the diagnostic approach and the timing of conservative as well as interventional endoscopic, radiological and surgical treatments.

[Acute pancreatitis: guideline-based diagnosis and treatment]

Acute pancreatitis is most frequently of biliary or alcoholic origin and less frequently due to iatrogenic (ERCP, medication) or metabolic causes. Diagnosis is usually based on abdominal pain and elevation of serum lipase to more than three-times the normal limit. Acute pancreatitis can either resolve quickly following an oedematous swelling or present as a severe necrotizing form. A major risk is the systemic inflammatory response syndrome (SIRS), which can cause multi-organ failure. Prediction of disease course is initially difficult, thus necessitating immediate therapy and regular re-evaluation. In order to prove or exclude biliary genesis, abdominal ultrasonography should first be performed and endoscopic ultrasound may also be required. Primary therapy includes rapid and correctly dosed fluid substitution. Biliary pancreatitis requires causal treatment. In the case of cholangitis, stone extraction must be performed immediately; in the absence of cholangitis, it might be advisable to wait for spontaneous stone clearance. Timely cholecystectomy is necessary in all cases of biliary pancreatitis.

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.

Early versus on-demand nasoenteric tube feeding in acute pancreatitis

BACKGROUND

Early enteral feeding through a nasoenteric feeding tube is often used in patients with severe acute pancreatitis to prevent gut-derived infections, but evidence to support this strategy is limited. We conducted a multicenter, randomized trial comparing early nasoenteric tube feeding with an oral diet at 72 hours after presentation to the emergency department in patients with acute pancreatitis.

METHODS

We enrolled patients with acute pancreatitis who were at high risk for complications on the basis of an Acute Physiology and Chronic Health Evaluation II score of 8 or higher (on a scale of 0 to 71, with higher scores indicating more severe disease), an Imrie or modified Glasgow score of 3 or higher (on a scale of 0 to 8, with higher scores indicating more severe disease), or a serum C-reactive protein level of more than 150 mg per liter. Patients were randomly assigned to nasoenteric tube feeding within 24 hours after randomization (early group) or to an oral diet initiated 72 hours after presentation (on-demand group), with tube feeding provided if the oral diet was not tolerated. The primary end point was a composite of major infection (infected pancreatic necrosis, bacteremia, or pneumonia) or death during 6 months of follow-up.

RESULTS

A total of 208 patients were enrolled at 19 Dutch hospitals. The primary end point occurred in 30 of 101 patients (30%) in the early group and in 28 of 104 (27%) in the on-demand group (risk ratio, 1.07; 95% confidence interval, 0.79 to 1.44; P=0.76). There were no significant differences between the early group and the on-demand group in the rate of major infection (25% and 26%, respectively; P=0.87) or death (11% and 7%, respectively; P=0.33). In the on-demand group, 72 patients (69%) tolerated an oral diet and did not require tube feeding.

CONCLUSIONS

This trial did not show the superiority of early nasoenteric tube feeding, as compared with an oral diet after 72 hours, in reducing the rate of infection or death in patients with acute pancreatitis at high risk for complications. (Funded by the Netherlands Organization for Health Research and Development and others; PYTHON Current Controlled Trials number, ISRCTN18170985.).

Nasogastric nutrition is efficacious in severe acute pancreatitis: a systematic review and meta-analysis

In patients with severe acute pancreatitis (AP), enteral nutrition is delivered by nasojejunal (NJ) tube to minimise pancreatic stimulation. Nasogastric (NG) feeding represents an alternative route. The primary objective of this systematic review and meta-analysis was to evaluate the efficacy of NG feeding. Secondary objectives were to compare the NG and NJ routes and assess the side effects of the former. The primary endpoint was exclusive NG feeding with delivery of 75 % of nutritional targets. Additional outcomes included change to total parenteral nutrition (TPN), increased pain or disease severity, vomiting, diarrhoea, delivery rate reduction and tube displacement. Among the retrieved studies, six were found to be eligible for the qualitative review and four for the meta-analysis. NG nutrition was received by 147 patients; exclusive NG feeding was achieved in 90 % (133/147). Of the 147 patients, 129 (87 %) received 75 % of the target energy. In studies where all subjects received exclusive NG nutrition, 82 % (seventy-four of the ninety patients) received >75 % of the intended energy. Compared with NJ nutrition, there was no significant difference in the delivery of 75 % of nutritional targets (pooled risk ratio (RR) 1·02; 95 % CI 0·75, 1·38.) or no increased risk of change to TPN (pooled RR 1·05; 95 % CI 0·45, 2·48), diarrhoea (pooled RR 1·28; 95 % CI 0·62, 2·66), exacerbation of pain (pooled RR 1·10; 95 % CI 0·47, 2·61) or tube displacement (pooled RR 0·44; 95 % CI 0·11, 1·73). Vomiting and diarrhoea were the most common side effects of NG feeding (13·3 and 12·9 %, respectively). With respect to the delivery of nutrition, 11·2 % of the patients required delivery rate reduction and 3·4 % dislodged the tube. Other side effects included elevated levels of aspirates (9·1 %), abdominal distension (1·5 %), pain exacerbation (7·5 %) and increased disease severity (1·6 %). In conclusion, NG feeding is efficacious in 90 % of patients. Further research is required to optimise the delivery of NG nutrition and examine ‘gut-rousing’ approaches to nutrition in patients with severe AP.

A systematic review of the extra-pancreatic infectious complications in acute pancreatitis

BACKGROUND AND AIM

Extra-pancreatic infectious complications in acute pancreatitis increase morbidity, but their incidence and association with infected pancreatic necrosis is unknown. Half of bacterial cultures of pancreatic necrosis are of non-enteric origin, raising the possibility of other sources of infection. The aim of this systematic review was to assess the incidence of extra-pancreatic infectious complications in acute pancreatitis, their timing, and relation to severity of pancreatitis and mortality.

METHODS

A systematic review was performed using Ovid MEDLINE, Embase and Cochrane Libraries, following PRISMA guidelines. Search terms were "Pancreatitis" AND "Infection" AND ("Complication" OR "Outcome").

RESULTS

19 studies with 1741 patients were included. Extra-pancreatic infectious complication incidence was 32% (95% CI 23-41%), with the commonest being respiratory infection (9.2%) and bacteraemia (8.4%). Extra-pancreatic infectious complications were not associated with the predicted severity or the mortality of acute pancreatitis. Only 3 studies reported a relation of timing between extra-pancreatic and pancreatic infectious complications.

CONCLUSIONS

This is the first systematic review to evaluate the incidence of extra-pancreatic infectious complications in acute pancreatitis, which a third of patients with acute pancreatitis will develop. Implications are vigilance and prompt treatment of extra-pancreatic infection, to reduce possibility of progression to infected pancreatic necrosis.

Early phase of acute pancreatitis: Assessment and management

Acute pancreatitis (AP) is a potentially life-threatening disease with a wide spectrum of severity. The overall mortality of AP is approximately 5%. According to the revised Atlanta classification system, AP can be classified as mild, moderate, or severe. Severe AP often takes a clinical course with two phases, an early and a late phase, which should both be considered separately. In this review article, we first discuss general aspects of AP, including incidence, pathophysiology, etiology, and grading of severity, then focus on the assessment of patients with suspected AP, including diagnosis and risk stratification, followed by the management of AP during the early phase, with special emphasis on fluid therapy, pain management, nutrition, and antibiotic prophylaxis.

Treatment options for acute pancreatitis

This Review covers the latest developments in the treatment of acute pancreatitis. The Atlanta Classification of acute pancreatitis has been revised, proposing several new terms and abandoning some of the old and confusing terminology. The 2012 Revised Atlanta Classification and the determinant-based classification aim to universally define the different local and systemic complications and predict outcome. The most important differences between these classifications are discussed. Several promising treatment options for the early management of acute pancreatitis have been tested, including the use of enteral nutrition and antibiotics as well as novel therapies such as haemofiltration and protease inhibitors. The results are summarized and the quality of evidence is discussed. Finally, new developments in the management of patients with infected pancreatic necrosis are addressed, including the use of the 'step-up approach' and results of minimally invasive necrosectomy.

Early oral refeeding based on hunger in moderate and severe acute pancreatitis: a prospective controlled, randomized clinical trial

OBJECTIVE

Early enteral nutrition is beneficial for acute pancreatitis (AP), but the optimal timing and criteria remain unclear. The aim of this study was to explore the feasibility and safety of early oral refeeding (EORF) based on hunger in patients with moderate or severe AP.

METHODS

In a prospective, single-center, controlled, randomized clinical trial (ChiCTR-TRC-12002994), eligible patients with moderate or severe AP were randomized to either EORF or conventional oral refeeding (CORF). Patients in the EORF group restarted an oral diet when they felt hungry, regardless of laboratory parameters. Those in the CORF group restarted an oral diet only when clinical and laboratory symptoms had resolved. Clinical outcomes were compared between the two groups.

RESULTS

In all, 146 eligible patients with moderate or severe AP were included and randomized to the EORF (n = 70) or CORF (n = 76) group. There were eight dropouts after randomization (three in EORF group; five in CORF group). The groups had similar baseline characteristics. The total length of hospitalization (13.7 ± 5.4 d versus 15.7 ± 6.2 d; P = 0.0398) and duration of fasting (8.3 ± 3.9 d versus 10.5 ± 5.1 d; P = 0.0047) were shorter in the EORF group than in the CORF group. There was no difference in the number of adverse events or complications between the two groups. The mean blood glucose level after oral refeeding was higher in the EORF group than in the CORF group (P = 0.0030).

CONCLUSIONS

This controlled, randomized clinical trial confirmed the effectiveness and feasibility of EORF based on hunger in patients with moderate or severe AP. EORF could shorten the length of hospitalization in patients with moderate or severe AP.

Early enteral nutrition with polymeric feeds was associated with chylous ascites in patients with severe acute pancreatitis

OBJECTIVE

Chylous ascites (CA) may be involved in the pathological process of severe acute pancreatitis (SAP), but the underlying mechanisms remain unknown. This study investigated the incidence of CA in patients with SAP and its relationship with enteral nutrition (EN).

METHODS

A retrospective review of 85 patients with SAP admitted to our hospital was performed. Patients starting EN within 72 hours after the onset of SAP were classified as the early EN (EEN) group, and others, as the later EN group. The incidences of CA and prognosis in the EEN and later EN groups were examined with nutrition preparation of polymeric formula or semielemental feed.

RESULTS

Thirteen (15.29%) of 85 patients were identified with CA. A higher incidence of CA was observed in EEN patients who received polymeric formula (9 of 33, P < 0.05). All patients with CA were successfully treated with a modified medium-chain triglyceride diet. Consequently, there were no differences in intensive care unit stay and in mortality rates in patients with or without CA.

CONCLUSIONS

There was a higher incidence of CA associated with early enteral feeding of polymeric formula in patients with SAP. Future studies are warranted to confirm our findings and evaluate better enteral feeding options to avoid CA.

Enteral nutrition in severe acute pancreatitis

Severe acute pancreatitis (SAP) patients often have high catabolism, negative nitrogen balance and high energy consumption, and the degree of negative nitrogen balance is directly related to the severity of the disease. The purpose of nutritional support is to establish positive nitrogen balance. In nearly a decade, evidence-based evidence suggests that enteral nutrition can reduce the incidence of pancreatic infection, organ failure and mortality. Enteral nutrition is not only a way of nutritional support, but also for the treatment of SAP. However, there are some debates over the timing, ways, nutrient solution composition and the use of ecological immune preparations. In this review, we focus on the proper timing, way and nutrient solution composition of EN.

Staged multidisciplinary step-up management for necrotizing pancreatitis

Background

Some 15 per cent of all patients with acute pancreatitis develop necrotizing pancreatitis, with potentially significant consequences for both patients and healthcare services.

Methods

This review summarizes the latest insights into the surgical and medical management of necrotizing pancreatitis. General management strategies for the treatment of complications are discussed in relation to the stage of the disease.

Results

Frequent clinical evaluation of the patient's condition remains paramount in the first 24–72 h of the disease. Liberal goal-directed fluid resuscitation and early enteral nutrition should be provided. Urgent endoscopic retrograde cholangiopancreatography is indicated when cholangitis is suspected, but it is unclear whether this is appropriate in patients with predicted severe biliary pancreatitis without cholangitis. Antibiotic prophylaxis does not prevent infection of necrosis and antibiotics are not indicated as part of initial management. Bacteriologically confirmed infections should receive targeted antibiotics. With the more conservative approach to necrotizing pancreatitis currently advocated, fine-needle aspiration culture of pancreatic or extrapancreatic necrosis will less often lead to a change in management and is therefore indicated less frequently. Optimal treatment of infected necrotizing pancreatitis consists of a staged multidisciplinary ‘step-up’ approach. The initial step is drainage, either percutaneous or transluminal, followed by surgical or endoscopic transluminal debridement only if needed. Debridement is delayed until the acute necrotic collection has become ‘walled-off’.

Conclusion

Outcome following necrotizing pancreatitis has improved substantially in recent years as a result of a shift from early surgical debridement to a staged, minimally invasive, multidisciplinary, step-up approach.