New international classification of acute pancreatitis: more than just 4 categories of severity

Relationship between Habitual Intake of Vitamins and New-Onset Prediabetes/Diabetes after Acute Pancreatitis

Vitamins have many established roles in human health. However, the role of habitual dietary intake of vitamins in glucose homeostasis in individuals after acute pancreatitis (AP) is yet to be elucidated. The aim was to investigate the associations between habitual intake of fat- and water-soluble vitamins/vitamers and markers of glucose metabolism (fasting plasma glucose (FPG), homeostasis model assessment insulin resistance (HOMA-IR) index, and homeostasis model assessment β-cell function (HOMA-β)) in individuals after AP. A total of 106 participants after AP were included in this cross-sectional study and were grouped based on glycaemic status: new-onset prediabetes/diabetes after AP (NODAP), pre-existing prediabetes/type 2 diabetes (T2DM), and normoglycaemia after AP (NAP). Habitual intake of seven fat-soluble vitamins/vitamers and seven water-soluble vitamins were determined by the EPIC-Norfolk food frequency questionnaire. Multiple linear regression analyses were conducted using five statistical models built to adjust for covariates (age, sex, daily energy intake, visceral/subcutaneous fat volume ratio, smoking status, daily alcohol intake, aetiology of AP, number of AP episodes, cholecystectomy, and use of antidiabetic medications). In the NODAP group, three fat-soluble vitamins/vitamers (α-carotene, β-carotene, and total carotene) were significantly associated with HOMA-β. One water-soluble vitamin (vitamin B3) was also significantly associated with HOMA-β in the NODAP group. None of the studied vitamins were significantly associated with FPG or HOMA-IR in the NODAP group. Prospective longitudinal studies and randomised controlled trials are now warranted to investigate if the observed associations between vitamin/vitamer intake and NODAP are causal and to unveil the specific mechanisms underlying their involvement with NODAP.

The "Two-Step" approach for classifying the severity of acute pancreatitis: A retrospective study

BACKGROUND

The Revised Atlanta Classification (RAC) and Determinant-Based Classification (DBC) are currently two widely adopted systems for evaluating the severity of acute pancreatitis (AP). This study aimed to overcome the inaccuracies and limitations that existed in them.

METHODS

We retrospectively analyzed 298 patients with AP. The "Two-Step" approach was divided into an early organ failure (OF) assessment: (I) none, (II) transient, (III) single persistent, and (IV) multiple persistent; and a later local complications assessment: (A) none, (B) sterile, and (C) infectious. Patients with AP who died before the second step were classified into category X. The "Two-Step" approach was then compared to the RAC and DBC.

RESULTS

As the patients' grades increased (I to IV), organ support treatment rates, intensive care unit lengths of stay, and mortalities increased. Invasive intervention rates displayed increasing trends with local complications aggravated (A to C). Patients in category X were older and had higher Marshall scores with the highest grades of severity.

CONCLUSIONS

By combining the early OF grades and the late local complications, the "Two-Step" approach represents an accurate classification system required for stratified studies of AP, and introduces the category X as the severest forms of AP.

Trajectories of glycaemia following acute pancreatitis: a prospective longitudinal cohort study with 24 months follow-up

BACKGROUND

New-onset diabetes is the most common sequela of acute pancreatitis (AP). Yet, prospective changes in glycaemia over time have never been investigated comprehensively in this study population. The primary aim was to determine the cumulative incidence of new-onset prediabetes and new-onset diabetes after AP over 24 months of follow-up in a prospective cohort study. The secondary aim was to identify trajectories of glycaemia during follow-up and their predictors at the time of hospitalisation.

METHODS

Patients with a prospective diagnosis of AP and no diabetes based on the American Diabetes Association criteria were followed up every 6 months up to 24 months after hospital discharge. Incidence of new-onset prediabetes/diabetes over each follow-up period was calculated. Group-based trajectory modelling was used to identify common changes in glycaemia. Multinomial regression analyses were conducted to investigate the associations between a wide array of routinely available demographic, anthropometric, laboratory, imaging, and clinical factors and membership in the trajectory groups.

RESULTS

A total of 152 patients without diabetes were followed up. The cumulative incidence of new-onset prediabetes and diabetes was 20% at 6 months after hospitalisation and 43% over 24 months of follow-up (p trend < 0.001). Three discrete trajectories of glycaemia were identified: normal-stable glycaemia (32%), moderate-stable glycaemia (60%), and high-increasing glycaemia (8%). Waist circumference was a significant predictor of moderate-stable glycaemia. None of the studied predictors were significantly associated with high-increasing glycaemia.

CONCLUSIONS

This first prospective cohort study of changes in glycaemia (determined at structured time points in unselected AP patients) showed that at least one out of five patients develops new-onset prediabetes or diabetes at 6 months of follow-up and more than four out of ten-in the first 2 years. Changes in glycaemia after AP follow three discrete trajectories. This may inform prevention or early detection of critical changes in blood glucose metabolism following an attack of AP and, hence, reduce the burden of new-onset diabetes after acute pancreatitis.

Pancreatic Hormone Responses to Mixed Meal Test in New-onset Prediabetes/Diabetes After Non-necrotizing Acute Pancreatitis

AIM

To investigate the pancreatic hormone responses to mixed meal test, in particular changes in insulin secretion, insulin sensitivity, and their interrelationship, in individuals with new-onset prediabetes or diabetes after non-necrotizing acute pancreatitis (NODAP) compared with healthy controls.

METHODS

Twenty-nine individuals with NODAP and 29 age-and sex-matched healthy controls were recruited. All participants (after fasting for at least 8 h) were given 12 oz. of BOOST drink and blood samples were collected before and after stimulation to measure insulin, C-peptide, glucagon, and pancreatic polypeptide. Indices of insulin sensitivity (HOMA-IS, 1/fasting insulin, Raynaud, and Matsuda) and insulin secretion (HOMA-β, Stumvoll, insulinogenic index 30' and 60') were calculated. Repeated measures analyses were conducted in the unadjusted and adjusted models.

RESULTS

Insulin and C-peptide levels were significantly higher in individuals with NODAP compared with controls during mixed meal test in both the unadjusted (P=0.001 for both) and adjusted (P=0.004 and P=0.006, respectively) models. HOMA-IS (P=0.005), 1/fasting insulin (P=0.018), Raynaud index (P=0.018), and Matsuda index (P=0.021) were significantly lower in individuals with NODAP, whereas HOMA-β (P=0.028) and Stumvoll index (P=0.013) were significantly higher. Glucagon and pancreatic polypeptide levels did not differ significantly between NODAP and controls during mixed meal test in both the unadjusted (P=0.345 and P=0.206, respectively) and adjusted (P=0.359 and P=0.158, respectively) models.

CONCLUSIONS

Decreased insulin sensitivity, β-cell compensation, and no significant change in postprandial levels of glucagon and pancreatic polypeptide characterize NODAP. The above findings may help develop an evidence-based protocol with a view to optimize control of glucose homeostasis in NODAP.

African-Americans and Indigenous Peoples Have Increased Burden of Diseases of the Exocrine Pancreas: A Systematic Review and Meta-Analysis

Ethnic health disparity is a well-acknowledged issue in many disease settings, but not diseases of the exocrine pancreas. A systematic review and meta-analysis was conducted to explore the race- and ethnicity-specific burden of diseases of the exocrine pancreas. Studies that compared health-related endpoints between two or more ethnicities were eligible for inclusion. Proportion meta-analyses were conducted to compare burden between groups. A total of 42 studies (24 on pancreatic cancer, 17 on pancreatitis, and one on pancreatic cyst) were included in the systematic review, of which 19 studies were suitable for meta-analyses. The incidence of pancreatic cancer was 1.4-fold higher among African-Americans, while the incidence of acute pancreatitis was 4.8-fold higher among an indigenous population (New Zealand Māori) compared with Caucasians. The prevalence of post-pancreatitis diabetes mellitus was up to 3.0-fold higher among certain ethnicities, including Asians, Pacific Islanders, and indigenous populations compared with Caucasians. The burden of diseases of the exocrine pancreas differs between ethnicities, with African-Americans and certain indigenous populations being at the greatest risk of developing these diseases. Development of race- and ethnicity-specific screening as well as protocols for lifestyle modifications may need to be considered with a view to reducing the disparities in burden of diseases of the exocrine pancreas.

The Use of International Classification of Diseases Codes to Identify Patients with Pancreatitis: A Systematic Review and Meta-analysis of Diagnostic Accuracy Studies

Background

Hospital discharge codes are increasingly used in gastroenterology research, but their accuracy in the setting of acute pancreatitis (AP) and chronic pancreatitis (CP), one of the most frequent digestive diseases, has never been assessed systematically. The aim was to conduct a systematic literature review and determine accuracy of diagnostic codes for AP and CP, as well as the effect of covariates.

Methods

Three databases (Pubmed, EMBASE and Scopus) were searched by two independent reviewers for relevant studies that used International Classification of Disease (ICD) codes. Summary estimates of sensitivity, specificity and positive predictive value were obtained from bivariate random-effects regression models. Sensitivity and subgroup analyses according to recurrence of AP and age of the study population were performed.

Results

A total of 24 cohorts encompassing 18,106 patients were included. The pooled estimates of sensitivity and specificity of ICD codes for AP were 0.85 and 0.96, respectively. The pooled estimates of sensitivity and specificity of ICD codes for CP were 0.75 and 0.94, respectively. The positive predictive value of ICD codes was 0.71 for either AP or CP. It increased to 0.78 when applied to incident episode of AP only. The positive predictive value decreased to 0.68 when the ICD codes were applied to paediatric patients.

Conclusion

Nearly three out of ten patients are misidentified as having either AP or CP with the indiscriminate use of ICD codes. Limiting the use of ICD codes to adult patients with incident episode of AP may improve identification of patients with pancreatitis in administrative databases.

Derivation and validation of the prediabetes self-assessment screening score after acute pancreatitis (PERSEUS)

BACKGROUND AND AIM

Approximately 40% of patients develop abnormal glucose metabolism after a single episode of acute pancreatitis. This study aimed to develop and validate a prediabetes self-assessment screening score for patients after acute pancreatitis.

METHODS

Data from non-overlapping training (n=82) and validation (n=80) cohorts were analysed. Univariate logistic and linear regression identified variables associated with prediabetes after acute pancreatitis. Multivariate logistic regression developed the score, ranging from 0 to 215. The area under the receiver-operating characteristic curve (AUROC), Hosmer-Lemeshow χ² statistic, and calibration plots were used to assess model discrimination and calibration. The developed score was validated using data from the validation cohort.

RESULTS

The score had an AUROC of 0.88 (95% CI, 0.80-0.97) and Hosmer-Lemeshow χ² statistic of 5.75 (p=0.676). Patients with a score of ≥75 had a 94.1% probability of having prediabetes, and were 29 times more likely to have prediabetes than those with a score of <75. The AUROC in the validation cohort was 0.81 (95% CI, 0.70-0.92) and the Hosmer-Lemeshow χ² statistic was 5.50 (p=0.599). Model calibration of the score showed good calibration in both cohorts.

CONCLUSION

The developed and validated score, called PERSEUS, is the first instrument to identify individuals who are at high risk of developing abnormal glucose metabolism following an episode of acute pancreatitis.

Early management of acute pancreatitis: A review of the best evidence

In the 20th century early management of acute pancreatitis often included surgical intervention, despite overwhelming mortality. The emergence of high-quality evidence (randomized controlled trials and meta-analyses) over the past two decades has notably shifted the treatment paradigm towards predominantly non-surgical management early in the course of acute pancreatitis. The present evidence-based review focuses on contemporary aspects of early management (which include analgesia, fluid resuscitation, antibiotics, nutrition, and endoscopic retrograde cholangiopancreatography) with a view to providing clear and succinct guidelines on early management of patients with acute pancreatitis in 2017 and beyond.

Associations between circulating levels of adipocytokines and abdominal adiposity in patients after acute pancreatitis

Adipocytokines are strongly associated with abdominal adiposity during the course of acute pancreatitis (AP). This study investigated associations between a panel of adipocytokines and abdominal adiposity in AP patients after hospital discharge, as well as the effect of several covariates. Fasting venous blood samples were collected to measure adiponectin, interleukin 6, leptin, monocyte chemoattractant protein 1, tumour necrosis factor α (TNFα), resistin, and retinol-binding protein 4. Waist circumference (WC), waist-hip ratio, and waist-height ratio (WheightR) were used as measures of abdominal adiposity. Generalised linear models were built, adjusting for age, sex, ethnicity, diabetes status, aetiology, duration since admission for AP, recurrence, and severity of AP. A total of 93 patients were studied, on average at 22 months after AP. Interleukin 6, TNFα, and leptin were significantly associated with WC in both the unadjusted and all the three adjusted models. Also, they were significantly associated with WheightR in both the unadjusted and the three adjusted models. Other studied adipocytokines did not show a consistent association or were not significantly associated with the abdominal adiposity indices. The results suggest that excess abdominal adiposity favours pro-inflammatory milieu in AP patients after hospital discharge, independent of diabetes and effect of other covariates.

Interleukin-6 is associated with chronic hyperglycemia and insulin resistance in patients after acute pancreatitis

BACKGROUND

Diabetes is a pervasive disease, with a mounting prevalence and burden on health care systems. Under this collective term of diabetes falls diabetes after diseases of the exocrine pancreas, a condition which was previously under-recognised and often mislabeled as type 2 diabetes mellitus and is now increasingly acknowledged as a stand-alone entity. However, there is a paucity of clinical studies investigating the underlying pathophysiology of diabetes after acute pancreatitis, the most frequent disease of the pancreas. This study aimed to investigate the role of adipocytokines in glucose metabolism after acute pancreatitis.

METHODS

This was a cross-sectional follow-up study of a patient cohort diagnosed with acute pancreatitis. Fasting venous blood samples were collected to analyse markers of glucose metabolism (fasting blood glucose, haemoglobin A1c, homeostasis model assessment (HOMA-IR) as a measure of insulin resistance) and adypocytokines (adiponectin, interleukin-6, leptin, monocyte chemoattractant protein-1, retinol binding protein-4, resistin, and tumor necrosis factor-α). Participants were categorized into two groups: normoglycemia after acute pancreatitis and chronic hyperglycemia after acute pancreatitis (CHAP). Binary logistic regression and linear regression analyses were used to investigate the association between each of the adipocytokines and markers of glucose metabolism. Potential confounders were adjusted for in multivariate analyses.

RESULTS

A total of 83 patients with acute pancreatitis were included, of whom 19 developed CHAP. Interleukin-6 was significantly associated with CHAP in both unadjusted and adjusted models (p = 0.030 and p = 0.018, respectively). Further, it was also significantly associated with HOMA-IR in both unadjusted and adjusted models (p = 0.029 and p = 0.037, respectively). Other adipocytokines were not significantly associated with markers of glucose metabolism.

CONCLUSION

Interleukin-6 appears to be implicated in the development of chronic hyperglycemia and insulin resistance in patients after acute pancreatitis. It may become a potential target in the prevention and early treatment of diabetes after diseases of the exocrine pancreas.

Relationship between pancreatic hormones and glucose metabolism: A cross-sectional study in patients after acute pancreatitis

Abnormal glucose metabolism is present in almost 40% of patients after acute pancreatitis, but its pathophysiology has been poorly investigated. Pancreatic hormone derangements have been sparingly studied to date, and their relationship with abnormal glucose metabolism is largely unknown. The aim was to investigate the associations between pancreatic hormones and glucose metabolism after acute pancreatitis, including the effect of potential confounders. This was a cross-sectional study of 83 adult patients after acute pancreatitis. Fasting venous blood was collected from all patients and used for analysis of insulin, glucagon, pancreatic polypeptide, amylin, somatostatin, C-peptide, glucose, and hemoglobin A1c. Statistical analyses were conducted using the modified Poisson regression, multivariable linear regression, and Spearman's correlation. Age, sex, body mass index, recurrence of acute pancreatitis, duration from first attack, severity, and etiology were adjusted for. Increased insulin was significantly associated with abnormal glucose metabolism after acute pancreatitis, in both unadjusted (P = 0.038) and adjusted (P = 0.001) analyses. Patients with abnormal glucose metabolism also had significantly decreased pancreatic polypeptide (P = 0.001) and increased amylin (P = 0.047) in adjusted analyses. Somatostatin, C-peptide, and glucagon were not changed significantly in both unadjusted and adjusted analyses. Increased insulin resistance and reduced insulin clearance may be important components of hyperinsulinemic compensation in patients after acute pancreatitis. Increased amylin and reduced pancreatic polypeptide fasting levels characterize impaired glucose homeostasis. Clinical studies investigating islet-cell hormonal responses to mixed-nutrient meal testing and euglycemic-hyperinsulinemic clamps are now warranted for further insights into the role of pancreatic hormones in glucose metabolism derangements secondary to pancreatic diseases.

The oral refeeding trilemma of acute pancreatitis: what, when and who?

Tolerance of oral refeeding is an essential goal of nutritional management of acute pancreatitis. However, oral feeding intolerance remains one of the most common complications in patients with this disease. It often results in longer periods of hospitalization, increased treatment costs, increased risk of readmission, and reduced quality of life. The traditional practice involves keeping patients nil by mouth followed by gradual stepwise reintroduction of food. However, it does not have a solid evidence base and, hence, there is increasing interest in determining alternative strategies that may be beneficial in reducing the occurrence of oral feeding intolerance. This review focuses on the randomized controlled trials that investigated the key questions informing the nutritional management of acute pancreatitis: when to feed, what to feed and who is in charge of the decision-making.

Acute Pancreatitis Classifications: Basis and Key Goals

To explore the efficacy of the revised Atlanta classification (RACAP) and the determinant-based classification of acute pancreatitis severity (DBCAPS) on the basis of clinical data and feedback from patients with acute pancreatitis (AP). The authors retrospectively investigated a total of 573 patients with AP admitted to our hospital between December 2011 and December 2014. The definitions of severity and local complications in AP using RACAP and DBCAPS are presented and common points and mutual differences between the 2 groups are analyzed and discussed. Classification according to RACAP and DBCAPS found 86 (15%) and 178 (31.1%) mild cases (P < 0.01), 269 (46.9%) and 176 (30.7%) moderate cases (P < 0.01), and 218 (38.0%) and 219 (38.2%) severe cases (P = 0.95), respectively. A major contribution of DBCAPS is the introduction of a new type of severe AP, critical AP, identified in 4 patients (0.7%). Complications were observed in 313 RACAP-defined cases and 153 DBCAPS-defined cases (P < 0.01). Among the 313 RACAP-defined cases, acute peripancreatic fluid collection (236 patients, 75.40%), pancreatic pseudocysts (20 patients, 6.4%), acute necrotic collection (42 patients, 13.4%), and walled-off necrosis (15 patients, 4.8%) were observed. Among the 153 DBCAPS-defined cases, sterile peripancreatic necrosis (105 patients, 68.6%), sterile pancreatic necrosis (44 patients, 28.8%), infected peripancreatic necrosis (2 patients, 1.3%), and infected pancreatic necrosis (2/153 patients, 1.3%) were observed. Both classifications adopted organ failure and complications as determinants of severity. Revised Atlanta classification refined local complications and DBCAPS modified severity to include critical AP. In accordance with the demands of precision medicine, a combination of the 2 could be important for further clinical practice and scientific research.

Effect of Nasogastric Tube Feeding vs Nil per Os on Dysmotility in Acute Pancreatitis: Results of a Randomized Controlled Trial

BACKGROUND

Evidence from animal studies suggests that gastrointestinal motility is impaired in acute pancreatitis. Enteral nutrition, and more specifically nasogastric tube feeding, has emerged as a key treatment modality in patients with acute pancreatitis, but its effect on motility has not been investigated in this setting. The aim was to validate the Gastroparesis Cardinal Symptom Index (GCSI) in patients with acute pancreatitis and determine the effect of nasogastric tube feeding on GCSI.

METHODS

The study design was a randomized controlled trial. Patients were allocated to nasogastric tube feeding or nil per os within 24 hours of hospital admission. GCSI data from before randomization to 72 hours after randomization were analyzed. The test-retest reliability analysis was used to calculate Cronbach's α.

RESULTS

Seventeen patients were randomized to nasogastric tube feeding and 18 to nil per os. Overall, the total GCSI score significantly decreased over the study (F = 8.537; P = .001) but was not significantly different between the 2 study groups during hospitalization (F = 1.159; P = .322). However, patients on nasogastric tube feeding did show improved appetite compared with nil per os (F = 3.526; P = .036). The GCSI was found to be a reliable tool in the setting of acute pancreatitis (Cronbach's α = 0.852).

CONCLUSIONS

Nasogastric tube feeding does not appear to affect dysmotility symptoms in acute pancreatitis as measured by the GCSI, although appetite improved. Use of the simple, noninvasive, and inexpensive GCSI tool to evaluate motility is recommended in future clinical trials in pancreatology.

Classifying the severity of acute pancreatitis: towards a way forward

BACKGROUND

The recent development of two different severity classifications for acute pancreatitis has appropriately raised questions about which should be used. The aim of this paper is to review the two new severity classifications, outline their differences, review validation studies, and identify gaps in knowledge to suggest a way forward.

METHODS

A literature review was performed to identify the purposes and differences between the classifications. Validation studies and those comparing the two different classifications were also reviewed.

RESULTS

The Revised Atlanta Classification (RAC) and the Determinants Based Classification (DBC) both rely on assessment of local and systemic factors. The differences between the classifications provides opportunities for further research to improve the accuracy and utility of severity classification. This includes understanding how best to tailor severity classification to setting (e.g. secondary or tertiary hospital) and purpose (e.g. clinical management or research). A key difference is that the RAC does not consider infected pancreatic necrosis an indicator of severe disease. There is also the need to develop methods for the accurate non-invasive diagnosis of infected necrosis and evaluation of the characteristics of organ dysfunction in relation to severity and outcome.

CONCLUSION

Further improvement in severity classification is possible and research priorities have been identified. For now, the decision as to which classification to use should be on the basis of setting, validity, accuracy, and ease of use.

Predictors of critical acute pancreatitis: a prospective cohort study

Critical acute pancreatitis (CAP) has recently emerged as the most ominous severity category of acute pancreatitis (AP). As such there have been no studies specifically designed to evaluate predictors of CAP. In this study, we aimed to evaluate the accuracy of 4 parameters (Acute Physiology and Chronic Health Evaluation [APACHE] II score, C-reactive protein [CRP], D-dimer, and intra-abdominal pressure [IAP]) for predicting CAP early after hospital admission. During the study period, data on patients with AP were prospectively collected and D-dimer, CRP, and IAP levels were measured using standard methods at admission whereas the APACHE II score was calculated within 24 hours of hospital admission. The receiver-operating characteristic (ROC) curve analysis was applied and the likelihood ratios were calculated to evaluate the predictive accuracy. A total of 173 consecutive patients were included in the analysis and 47 (27%) of them developed CAP. The overall hospital mortality was 11% (19 of 173). APACHE II score ≥11 and IAP ≥13 mm Hg showed significantly better overall predictive accuracy than D-dimer and CRP (area under the ROC curve-0.94 and 0.92 vs. 0.815 and 0.667, correspondingly). The positive likelihood ratio of APACHE II score is excellent (9.9) but of IAP is moderate (4.2). The latter can be improved by adding CRP (5.8). In conclusion, of the parameters studied, APACHE II score and IAP are the best available predictors of CAP within 24 hours of hospital admission. Given that APACHE II score is rather cumbersome, the combination of IAP and CRP appears to be the most practical way to predict critical course of AP early after hospital admission.

Quality of life after acute pancreatitis: a systematic review and meta-analysis

Patient-centered outcomes, including quality of life (QoL), after acute pancreatitis (AP) remain largely unknown. Our aim was to systematically review the best available evidence on QoL after AP. English-language articles on the effect of AP on QoL were identified in MEDLINE, EMBASE, and Scopus. Results were statistically aggregated to obtain a pooled mean difference (MD) and corresponding 95% confidence interval (CI) for individual QoL domains and component summaries, where appropriate. A total of 16 prospective observational studies encompassing 687 AP patients were included. Four studies comprising 267 AP patients, as measured by SF-36 and SF-12 questionnaires, were suitable for meta-analysis. The general health and vitality domains were significantly worse in the patients compared with healthy controls (MD, -10.90; 95% CI, -15.63 to -6.17; P < 0.00001 and MD, -4.64; 95% CI, -7.32 to -1.95; P = 0.0007, respectively). The remaining individual domains and physical and mental component summary scores did not differ between patients and controls. The QoL seems to be significantly impaired in patients after AP with a need to standardize reporting on QoL. Future studies should investigate the effect of different interventions on patients' QoL.

Predictors of severe and critical acute pancreatitis: a systematic review

BACKGROUND

Persistent organ failure and infected pancreatic necrosis are major determinants of mortality in acute pancreatitis, but there is a gap in the literature assessing the best available predictors of these two determinants. The purpose of this review was to investigate the utility of predictors of persistent organ failure and infected pancreatic necrosis in patients with acute pancreatitis, both alone and in combination.

METHODS

We performed a systematic search of the literature in 3 databases for prospective studies evaluating predictors of persistent organ failure, infected pancreatic necrosis, or both, with strict eligibility criteria.

RESULTS

The best predictors of persistent organ failure were the Japanese Severity Score and Bedside Index of Severity in Acute Pancreatitis when the evaluation was performed within 48h of admission, and blood urea nitrogen and Japanese Severity Score after 48h of admission. Systemic Inflammation Response Syndrome was a poor predictor of persistent organ failure. The best predictor of infected pancreatic necrosis was procalcitonin.

CONCLUSIONS

Based on the best available data, it is justifiable to use blood urea nitrogen for prediction of persistent organ failure after 48h of admission and procalcitonin for prediction of infected pancreatic necrosis in patients with confirmed pancreatic necrosis. There is no predictor of persistent organ failure that can be justifiably used in clinical practice within 48h of admission.

From nitric oxide to hyperbaric oxygen: invisible and subtle but nonnegligible gaseous signaling molecules in acute pancreatitis

Nitric oxide (NO), carbon monoxide, and hydrogen sulfide in addition to hydrogen are well established as gaseous signal molecules throughout the body. Although the role of gasotransmitters in acute pancreatitis (AP) has been explored for many years, many details remain to be elucidated. The physiologic effect of NO in AP mainly relies on induced NO synthase, which stimulates the production of cytokines in the blood. Carbon monoxide inhibits nuclear factor-κB activation, which leads to amelioration of the inflammatory response. Hydrogen sulfide displays a dual role in the mechanism of AP according to its concentration in the system. Hydrogen is a newly discovered gaseous signaling molecule, and currently, there is little evidence that it has any function in alleviating inflammation. We discovered that hyperbaric oxygen is a novel gasotransmitter that has potential use in the treatment of AP. The correlation among hyperbaric oxygen, hypoxia inducible factor 1α, and other signaling pathways should be further studied. We also discuss some prospects and issues that remain to be resolved in this review. In summary, the discovery of gaseous signal molecules has established a new platform for deep investigation of the mechanism of AP, and our knowledge of the role of gasotransmitters in AP will increase with further research.

Revised Atlanta and determinant-based classification: application in a prospective cohort of acute pancreatitis patients

OBJECTIVES

Atlanta classification (Atlanta 1992) of acute pancreatitis (AP) has several limitations. Two new classification systems were recently proposed: the Atlanta reclassification (Atlanta 2012) and the determinant-based classification (DBC). The aim of our study was to: (i) determine the association between different severity categories and clinical outcomes and (ii) perform a head-to-head comparison between Atlanta 1992, Atlanta 2012, and DBC in predicting these clinical outcomes.

METHODS

A total of 256 prospectively enrolled patients were assigned a severity category for all three classifications. Five clinical outcomes were evaluated: mortality, intensive care unit (ICU) admission and length of stay (LOS), need for interventions, and hospital LOS. Pairwise testing between severity grades within a classification system was performed using Fisher's exact and Kruskal-Wallis tests. Predictive accuracies were evaluated using area under the ROC curve (AUC) and Somer's D co-efficient.

RESULTS

Overall, higher grades of severity were associated with worse clinical outcomes for all three classification systems. Atlanta 2012 and DBC performed better than Atlanta 1992 and were comparable in predicting mortality (AUC 0.89 for both vs. 0.76, P<0.001), ICU admission (AUC 0.91 for both vs. 0.80, P<0.001), and ICU LOS (Somer's D 0.21 and 0.28 vs. 0.07, P<0.05). DBC performed better in predicting need for interventions (AUC 0.93 vs. 0.85, P<0.001), whereas Atlanta 2012 performed better in predicting hospital LOS (Somer's D 0.43 vs. 0.37, P=0.04).

CONCLUSIONS

Atlanta 2012 and DBC severity categories accurately reflected clinical outcomes in our cohort and were superior to Atlanta 1992. These novel classification systems can guide the selection of homogeneous patient populations for clinical research and provide an accurate spectrum of disease severity categories in the clinical setting.

Nutritional management of acute pancreatitis: the concept of 'gut rousing'

PURPOSE OF REVIEW

Enteral nutrition has emerged as one of the most effective treatments in the early management of patients with acute pancreatitis. The original rationale for nutrition in acute pancreatitis, dating back to the mid-20th century, was to provide full nutritional requirements but avoid stimulating exocrine pancreatic secretion. The purpose of this article is to review the recent clinical studies of enteral nutrition in acute pancreatitis to revise the rationale and develop a contemporary conceptual framework for nutritional management of this disease.

RECENT FINDINGS

Several recent randomized controlled trials dispel the outdated concept of 'pancreatic rest', which equates with gut neglect, and offer 'gut rousing' as a preferred concept. The new concept postulates that gastrointestinal (dys)function has a discernible impact on the outcomes of patients with acute pancreatitis. Further, timely administration of appropriate intraluminal modalities prevents or mitigates the gastrointestinal dysfunction.

SUMMARY

Nutritional management in acute pancreatitis should aim primarily at maintaining the gastrointestinal function. Providing full nutritional requirements and avoiding pancreatic exocrine stimulation should be considered as secondary aims.

Moving beyond the 'pancreatic rest' in severe and critical acute pancreatitis

Nasojejunal tube feeding is considered the current standard of care in patients with severe and critical acute pancreatitis. However, it is not known whether enteral nutrition is best delivered into the jejunum. This Commentary discusses recent clinical studies that have shown that tube feeding into the stomach is safe and well tolerated in the vast majority of patients with acute pancreatitis, thus overthrowing the notion of putting the pancreas at rest. Development of a new conceptual framework is warranted to further advance nutritional management of patients with acute pancreatitis.