Double blind, randomised, placebo controlled study of a platelet activating factor antagonist, lexipafant, in the treatment and prevention of organ failure in predicted severe acute pancreatitis

Evidence-based treatment of acute pancreatitis: a look at established paradigms

BACKGROUND

The management of acute pancreatitis (AP) is still based on speculative and unproven paradigms in many centers. Therefore, we performed an evidence-based analysis to assess the best available treatment.

METHODS

A comprehensive Medline and Cochrane Library search was performed evaluating the indication and timing of interventional and surgical approaches, and the value of aprotinin, lexipafant, gabexate mesylate, and octreotide treatment. Each study was ranked according to the evidence-based methodology of Sackett; whenever feasible, we performed new meta-analyses using the random-effects model. Recommendations were based on the available level of evidence (A=large randomized; B=small randomized; C=prospective trial).

RESULTS

None of the evaluated medical treatments is recommended (level A). Patients with AP should receive early enteral nutrition (level B). While mild biliary AP is best treated by primary cholecystectomy (level B), patients with severe biliary AP require emergency endoscopic papillotomy followed by interval cholecystectomy (level A). Patients with necrotizing AP should receive imipenem or meropenem prophylaxis to decrease the risk of infected necrosis and mortality (level A). Sterile necrosis per se is not an indication for surgery (level C), and not all patients with infected necrosis require immediate surgery (level B). In general, early necrosectomy should be avoided (level B), and single necrosectomy with postoperative lavage should be preferred over "open-packing" because of fewer complications with comparable mortality rates (level C).

CONCLUSIONS

While providing new insights into key aspects of AP management, this evidence-based analysis highlights the need for further clinical trials, particularly regarding the indications for antibiotic prophylaxis and surgery.

Pharmacological prevention and treatment of acute pancreatitis: where are we now?

Acute pancreatitis is a disease of increasing prevalence, unchanged mortality over many decades, and limited treatment strategies. Progress has been made in developing therapies that reduce the rate of endoscopic retrograde cholangiopancreatography (ERCP)-associated pancreatitis and in preventing infected pancreatic necrosis with intravenous carbapenems. Attempts at reducing pancreatic enzyme output or inhibiting the activity of digestive enzyme proteases have not yielded encouraging results - nor have anti-inflammatory strategies for the treatment of acute pancreatitis been found to be effective so far. Future therapeutic options that are presently being developed or under investigation attempt to restore pancreatic secretory function, interfere with inflammatory pathways in a more effective manner, or inhibit digestive enzyme proteases more selectively.

JPN Guidelines for the management of acute pancreatitis: epidemiology, etiology, natural history, and outcome predictors in acute pancreatitis

Acute pancreatitis is a common disease with an annual incidence of between 5 and 80 people per 100,000 of the population. The two major etiological factors responsible for acute pancreatitis are alcohol and cholelithiasis (gallstones). The proportion of patients with pancreatitis caused by alcohol or gallstones varies markedly in different countries and regions. The incidence of acute alcoholic pancreatitis is considered to be associated with high alcohol consumption. Although the incidence of alcoholic pancreatitis is much higher in men than in women, there is no difference in sexes in the risk involved after adjusting for alcohol intake. Other risk factors include endoscopic retrograde cholangiopancreatography, surgery, therapeutic drugs, HIV infection, hyperlipidemia, and biliary tract anomalies. Idiopathic acute pancreatitis is defined as acute pancreatitis in which the etiological factor cannot be specified. However, several studies have suggested that this entity includes cases caused by other specific disorders such as microlithiasis. Acute pancreatitis is a potentially fatal disease with an overall mortality of 2.1%-7.8%. The outcome of acute pancreatitis is determined by two factors that reflect the severity of the illness: organ failure and pancreatic necrosis. About half of the deaths in patients with acute pancreatitis occur within the first 1-2 weeks and are mainly attributable to multiple organ dysfunction syndrome (MODS). Depending on patient selection, necrotizing pancreatitis develops in approximately 10%-20% of patients and the mortality is high, ranging from 14% to 25% of these patients. Infected pancreatic necrosis develops in 30%-40% of patients with necrotizing pancreatitis and the incidence of MODS in such patients is high. The recurrence rate of acute pancreatitis is relatively high: almost half the patients with acute alcoholic pancreatitis experience a recurrence. When the gallstones are not treated, the risk of recurrence in gallstone pancreatitis ranges from 32% to 61%. After recovering from acute pancreatitis, about one-third to one-half of acute pancreatitis patients develop functional disorders, such as diabetes mellitus and fatty stool; the incidence of chronic pancreatitis after acute pancreatitis ranges from 3% to 13%. Nevertheless, many reports have shown that most patients who recover from acute pancreatitis regain good general health and return to their usual daily routine. Some authors have emphasized that endocrine function disorders are a common complication after severe acute pancreatitis has been treated by pancreatic resection.

Immunomodulation in surgical practice

BACKGROUND

Immunomodulation may represent a potential way to improve surgical outcome. These types of interventions should be based on detailed knowledge of the underlying mechanisms involved. The aim of the present review is to summarize some experience on the acute phase response, potential ways of intervention and experiences from critical illness and HPB disease.

DISCUSSION

Mechanisms of the acute phase response are discussed including the individual parameters and local changes that take part. Mechanisms involved in failure of the gut barrier are presented and include changes in gut barrier permeability, effects on gut-associated immunocompetent cells, and systemic implications. As examples of HPB disease, mechanisms of the acute phase response and potential ways of intervention in obstructive jaundice and acute pancreatitis are discussed. Nutritional pharmacology and lessons learned from immunomodulation and immunonutrition in critical illness and major abdominal surgery, including upper GI and HPB surgery, are referred to. Overall, immunomodulation represents a potential tool to improve results but requires a thorough mapping of underlying mechanisms in order to achieve individualized treatment or prevention based on patients' specific needs.

Pancreatic acinar cell: its role in acute pancreatitis

The pancreatic acinar cell is the functional unit of the exocrine pancreas. It synthesizes, stores, and secretes digestive enzymes. Under normal physiological conditions, digestive enzymes are activated only once they have reached the duodenum. Premature activation of these enzymes within pancreatic acinar cells leads to the onset of acute pancreatitis; it is the major clinical disorder associated with pancreatic acinar cells. Although there have been major advances in our understanding of the pathogenesis of this disease in recent years, available treatment options are still limited to traditional nonspecific and palliative interventions. Novel therapeutic strategies have been suggested based on ongoing research in the physiology and pathophysiology of the disease; these include the administration of systemic antibiotics, antioxidants, cytokine antagonists, and more recently, inhibition of the renin-angiotensin system. Notwithstanding this promising development, most of these potential therapies are still in an experimental stage or clinical trial. Further investigation is needed to prove the efficacy of these novel treatment modalities.

Machine learning can improve prediction of severity in acute pancreatitis using admission values of APACHE II score and C-reactive protein

BACKGROUND

Acute pancreatitis (AP) has a variable course. Accurate early prediction of severity is essential to direct clinical care. Current assessment tools are inaccurate, and unable to adapt to new parameters. None of the current systems uses C-reactive protein (CRP). Modern machine-learning tools can address these issues.

METHODS

370 patients admitted with AP in a 5-year period were retrospectively assessed; after exclusions, 265 patients were studied. First recorded values for physical examination and blood tests, aetiology, severity and complications were recorded. A kernel logistic regression model was used to remove redundant features, and identify the relationships between relevant features and outcome. Bootstrapping was used to make the best use of data and obtain confidence estimates on the parameters of the model.

RESULTS

A model containing 8 variables (age, CRP, respiratory rate, pO2 on air, arterial pH, serum creatinine, white cell count and GCS) predicted a severe attack with an area under the receiver-operating characteristic curve (AUC) of 0.82 (SD 0.01). The optimum cut-off value for predicting severity gave sensitivity and specificity of 0.87 and 0.71 respectively. The predictions were significantly better (p = 0.0036) than admission APACHE II scores in the same patients (AUC 0.74) and better than historical admission APACHE II data (AUC 0.68-0.75).

CONCLUSIONS

This system for the first time combines admission values of selected components of APACHE II and CRP for prediction of severe AP. The score is simple to use, and is more accurate than admission APACHE II alone. It is adaptable and would allow incorporation of new predictive factors.

Neutrophil engagement and septic challenge in acute experimental pancreatitis in rats

AIM: To investigate the influence of neutrophil adhesion molecule blockade with monoclonal antibody (MoAb CD11b) and E. coli lipopolysaccharide (LPS) administration on experimental acute pancreatitis (AP).

METHODS: AP was induced by four ip injections of cerulein (Cn) at 1-h intervals. MoAb CD 11b and LPS were administered at the beginning of the experiment.

RESULTS: The neutrophil count and chemiluminescence were diminished at the beginning of AP. The oxidative stress parameters were found within the pancreatic gland. MoAb CD 11b used for AP resulted in a significant reduction of pancreatic infiltration and pancreatitis oxidative stress parameters. Serum interleukin-6 (IL-6) was not detected in AP animals, whereas high serum IL-6 concentration was noted only in animals receiving LPS.

CONCLUSION: Neutrophils are involved in pancreatic damage in the early stage of AP. Neutrophil infiltration reduction protects the pancreatic gland from destruction during AP. LPS does not change the early course of Cn pancreatitis in rats.

Pancreatitis and pancreatic trauma

Many pancreatic disorders in children benefit from a multidisciplinary approach. This is especially true for acute and chronic pancreatitis which has numerous and diverse etiologies. The current management of pancreatitis is reviewed, focusing on recent advances. Children with pancreatitis must be fully investigated, not least to select out those who benefit from specific surgical interventions. The treatment of pancreas divisum, pseudocysts, and fibrosing pancreatitis deserve particular consideration. Management of pancreatic injuries involving the main pancreatic duct is both variable and controversial. Treatment should be individualized depending on the site of injury, timing of referral, presence of associated injuries, and institutional expertise.

Factors influencing mortality in acute pancreatitis: can we alter them?

Severe acture pancreatitis (SAP), a multisystem disease, is characterized by multiple organ system failure and additionally by local pancreatic complications such as necrosis, abscess, or pseudocyst. The rate of mortality in SAP, which is about 20% of all cases of acute pancreatitis (AP), may be as high as 25%, as in infected pancreatic necrosis. The factors that influence mortality in different degrees are various. Etiology for the episode, age, sex, race, ethnicity, genetic makeup, severity on admission, and the extent and nature of pancreatic necrosis (sterile vs. infected) influence the mortality. Other factors include treatment modalities such as administration of prophylactic antibiotics, the mode of feeding (TPN vs. enteral), ERCP with sphincterotomy, and surgery in selected cases. Epidemiological studies indicate that the incidence of AP is increasing along with an increase in obesity, a bad prognostic factor. Many studies have indicated a worse prognosis in idiopathic AP compared to pancreatitis induced by alcoholism or biliary stone. The risk for SAP after ERCP is the subject of extensive study. AP after trauma, organ transplant, or coronary artery bypass surgery is rare but may be serious. Since Ranson reported early prognostic criteria, a number of attempts have been made to simplify or add new clinical or laboratory studies in the early assessment of severity. Obesity, hemoconcentration on admission, presence of pleural effusion, increased fasting blood sugar, as well as creatinine, elevated CRP in serum, and urinary trypsinogen levels are some of the well-documented factors in the literature. The role of appropriate prophylactic antibiotic therapy although still is highly controversial, in properly chosen cases appears to be beneficial and well accepted in clinical practice. Early enteral nutrition has gained much support and jejunal feeding bypassing the pancreatic stimulatory effect of it in the duodenum is desirable in selected cases. The limited role for endoscopic sphincterotomy in patients with demonstrated dilated CBD with impacted stone and evidence of impending cholangitis is well documented. Surgery in AP other than for removal of the gallbladder is often limited to infected pancreatic necrosis, pseudocysts, and pancreatic abscess and in some cases of traumatic pancreatitis with a ruptured duct system. The progress in the understanding of the role of cytokines will over us opportunities to use immunomodulatory therapies to improve the outcome in SAP.

Potential role of reactive oxygen species in pancreatitis-associated multiple organ dysfunction

BACKGROUND

Severe acute pancreatitis is still associated with substantial morbidity and mortality. Experimental and clinical studies have demonstrated that reactive oxygen species (ROS) represent early occurring inflammatory mediators contributing to cell dysfunction, both locally in the pancreas and remote organs.

METHOD

A systematic literature review was conducted to investigate the potential roles of intra- and intercellular, as well as interorgan signaling of ROS in the development of pancreatitis-associated multiple organ dysfunction syndrome (MODS). A text word search of the Medline, PubMed and Cochrane databases, and a manual search of the citations from these references, was performed.

RESULTS

ROS directly compromise cellular damage and regulate intercellular signals in pancreatitis-associated MODS. ROS are involved in leukocyte activation, production of cytokines, endothelial barrier dysfunction, and microcirculatory barrier dysfunction in acute pancreatitis. Beside effects on intercellular signaling, ROS also affect intracellular events and activate the transcription factor nuclear factor kappa B that regulates inflammatory cytokine expression.

CONCLUSION

ROS is a critical factor responsible for the development of pancreatitis-induced remote organ dysfunction via intercellular and interorgan signaling. The role of antioxidant treatment, included as a part of multimodal management, remains to be investigated.

Platelet function in acute experimental pancreatitis induced by ischaemia-reperfusion

BACKGROUND

Ischaemia-reperfusion (IR)-associated microcirculatory changes play a major role in acute post-transplantation pancreatitis. The pathophysiological role of platelets in these events is unknown. The aim of this study was to examine platelet adhesion and function during early reperfusion after pancreatic ischaemia.

METHODS

Rats were subjected to warm pancreatic ischaemia by cross-clamping of the pancreatic vessels for 1 h. After 1 h of reperfusion, platelet-endothelium interaction was evaluated after platelet separation and staining by fluorescence microscopy. Amylase levels and pancreatic histology were evaluated 24 h after reperfusion. Animals treated according to an identical protocol, but without ischaemia, served as controls.

RESULTS

Mild pancreatitis had developed by 24 h after IR; serum amylase levels were significantly higher than those in control animals. The numbers of adherent platelets in capillaries and venules were significantly increased, and platelet velocity in capillaries was significantly decreased, in the IR group compared with controls. There was significantly more oedema and inflammation in pancreatic tissue after IR.

CONCLUSION

Warm ischaemia for 1 h followed by reperfusion for 24 h caused mild pancreatitis in this experimental model. The pancreatic microcirculation was characterized by pronounced platelet-endothelium interaction in capillaries and venules. These results suggest that platelet activation may play an important role in acute post-transplantation pancreatitis.

Monocyte anergy is present in patients with severe acute pancreatitis and is significantly alleviated by granulocyte-macrophage colony-stimulating factor and interferon-gamma in vitro

OBJECTIVES

Severe acute pancreatitis (AP) is frequently associated with immune suppression, which increases the risk of infections, organ failure, and death. Our aims were to measure monocyte function (ie, HLA-DR expression and tumor necrosis factor-alpha [TNF-alpha] production as markers of immune suppression) in patients with severe AP and to determine whether treatment of blood samples with granulocyte-macrophage colony-stimulating factor (GM-CSF) and/or interferon-gamma (IFN-gamma) corrected the functional defects of monocytes in vitro.

METHODS

The study consisted of 28 patients with severe AP who were treated at intensive care unit and in whom the proportion of HLA-DR-positive monocytes in the circulation was less than 70%, and 28 matched control subjects who were selected from healthy laboratory personnel. HLA-DR density was determined by whole blood flow cytometry. Monocyte TNF-alpha production in response to bacterial lipopolysaccharides (LPSs) was studied in a whole blood assay. Aliquots of blood were supplemented with IFN-gamma (all 28 patients), GM-CSF (the last 24 patients), or both (the last 12 patients).

RESULTS

The median proportion of HLA-DR-positive monocytes was 45% in patients (range, 18%-73%) and was 98% in controls (range, 86%-100%; P < 0.001). TNF-alpha levels in response to LPSs were lower in patients (545 pg/mL; range, 84-1990 pg/mL) than in controls (1415 pg/mL; range, 660-5490 pg/mL; P < 0.001). The proportion of HLA-DR-positive cells correlated positively with TNF-alpha levels (r = 0.56; P < 0.01). Both GM-CSF and IFN-gamma increased HLA-DR expression of monocytes in patients (98%; range, 74%-100% for GM-CSF; 99%; range, 86%-100% for IFN-gamma; both P < 0.001). The combination restored monocyte HLA-DR expression (99%; range, 96%-100%; P = 0.002). Compared with basal levels, GM-CSF increased TNF-alpha production of monocytes both in blood samples from patients (median, 1320 pg/mL; range, 35-8015 pg/mL) and controls (median, 3450 pg/mL; range, 1040-9835 pg/mL; both P < 0.001). IFN-gamma increased TNF-alpha production by monocytes in patients (683 pg/mL; range, 186-2705 pg/mL; P < 0.05) but not in controls (1658 pg/mL; range, 765-4755 pg/mL; P = 0.31). With the combination of GM-CSF and IFN-gamma, the TNF-alpha levels of monocytes in patients (3185 pg/mL; range, 545-8280 pg/mL) and in controls (2800 pg/mL; range, 1080-6860 pg/mL) were comparable.

CONCLUSIONS

The proportion of HLA-DR-positive monocytes correlates with TNF-alpha production, and they both reflect the degree of immune suppression. The low proportion of HLA-DR-positive monocytes in AP can be reversed in vitro by GM-CSF and/or IFN-gamma. The GM-CSF and IFN-gamma treatments also increase LPS-induced TNF-alpha production. By the combination of GM-CSF and IFN-gamma, but not by either agent alone, LPS-induced TNF-alpha production of monocytes was equally high in patients and in controls.

Pathophysiology of acute pancreatitis

Acute pancreatitis is a common clinical condition. It is a disease of variable severity in which some patients experience mild, self-limited attacks while others manifest a severe, highly morbid, and frequently lethal attack. The exact mechanisms by which diverse etiological factors induce an attack are still unclear. It is generally believed that the earliest events in acute pancreatitis occur within acinar cells. Acinar cell injury early in acute pancreatitis leads to a local inflammatory reaction. If this inflammatory reaction is marked, it leads to a systemic inflammatory response syndrome (SIRS). An excessive SIRS leads to distant organ damage and multiple organ dysfunction syndrome (MODS). MODS associated with acute pancreatitis is the primary cause of morbidity and mortality in this condition. Recent studies have established the role played by inflammatory mediators in the pathogenesis of acute pancreatitis and the resultant MODS. At the same time, recent research has demonstrated the importance of acinar cell death in the form of apoptosis and necrosis as a determinant of pancreatitis severity. In this review, we will discuss about our current understanding of the pathophysiology of acute pancreatitis.

Early prediction of organ failure by combined markers in patients with acute pancreatitis

BACKGROUND

Several biological markers and clinical scoring systems have been used to predict the course of acute pancreatitis. Because organ failure is the most severe complication of the disease, prognostic markers and their combinations that would predict organ failure on hospital admission were sought.

METHODS

Some 351 consecutive patients with acute pancreatitis were studied. Blood samples were taken within 12 h of admission. This case-control study included all 33 patients with organ failure and 99 matched controls without organ failure. Measurements included 19 prognostic markers and Acute Physiology And Chronic Health Evaluation (APACHE) II score.

RESULTS

Plasma interleukin 10, serum glucose and serum calcium were identified as independent predictors of organ failure by logistic regression analysis. Calcium level correlated with clinical onset of organ failure. The combination of interleukin 10 (more than 50 pg/ml) or calcium (less than 1.65 mmol/l) was a significantly better predictor than any single marker or APACHE II score, with a sensitivity of 88 per cent, specificity 93 per cent and diagnostic odds ratio 94.

CONCLUSION

Organ failure in acute pancreatitis can be predicted with high accuracy at hospital admission using a combination of plasma interleukin 10 and serum calcium measurements.

Management of the critically ill patient with severe acute pancreatitis

OBJECTIVE

Acute pancreatitis represents a spectrum of disease ranging from a mild, self-limited course requiring only brief hospitalization to a rapidly progressive, fulminant illness resulting in the multiple organ dysfunction syndrome (MODS), with or without accompanying sepsis. The goal of this consensus statement is to provide recommendations regarding the management of the critically ill patient with severe acute pancreatitis (SAP).

DATA SOURCES AND METHODS

An international consensus conference was held in April 2004 to develop recommendations for the management of the critically ill patient with SAP. Evidence-based recommendations were developed by a jury of ten persons representing surgery, internal medicine, and critical care after conferring with experts and reviewing the pertinent literature to address specific questions concerning the management of patients with severe acute pancreatitis.

DATA SYNTHESIS

There were a total of 23 recommendations developed to provide guidance to critical care clinicians caring for the patient with SAP. Topics addressed were as follows. 1) When should the patient admitted with acute pancreatitis be monitored in an ICU or stepdown unit? 2) Should patients with severe acute pancreatitis receive prophylactic antibiotics? 3) What is the optimal mode and timing of nutritional support for the patient with SAP? 4) What are the indications for surgery in acute pancreatitis, what is the optimal timing for intervention, and what are the roles for less invasive approaches including percutaneous drainage and laparoscopy? 5) Under what circumstances should patients with gallstone pancreatitis undergo interventions for clearance of the bile duct? 6) Is there a role for therapy targeting the inflammatory response in the patient with SAP? Some of the recommendations included a recommendation against the routine use of prophylactic systemic antibacterial or antifungal agents in patients with necrotizing pancreatitis. The jury also recommended against pancreatic debridement or drainage for sterile necrosis, limiting debridement or drainage to those with infected pancreatic necrosis and/or abscess confirmed by radiologic evidence of gas or results or fine needle aspirate. Furthermore, the jury recommended that whenever possible, operative necrosectomy and/or drainage be delayed at least 2-3 wk to allow for demarcation of the necrotic pancreas.

CONCLUSIONS

This consensus statement provides 23 different recommendations concerning the management of patients with SAP. These recommendations differ in several ways from previous recommendations because of the release of recent data concerning the management of these patients and also because of the focus on the critically ill patient. There are a number of important questions that could not be answered using an evidence-based approach, and areas in need of further research were identified.

Inflammatory response on the pancreatic acinar cell injury

Acute pancreatitis is an inflammatory disorder, and inflammation not only affects the pathogenesis but also the course of the disease. Acinar cell injury early in acute pancreatitis leads to a local inflammatory reaction; if marked this leads to a systemic inflammatory response syndrome (SIRS). An excessive SIRS leads to distant organ damage and multiple organ dysfunction syndrome (MODS). MODS associated with acute pancreatitis is the primary cause of morbidity and mortality in this condition. Recent studies by us and other investigators have established the critical role played by inflammatory mediators such as TNF-alpha, IL-1beta, IL-6, IL-8, CINC/GRO-alpha, MCP-1, PAF, IL-10, CD40L, C5a, ICAM-1, MIP1-alpha, RANTES, substance P, and hydrogen sulfide in acute pancreatitis and the resultant MODS. This review intends to present an overview of the inflammatory response that takes place following pancreatic acinar cell injury.

Membrane-bound ICAM-1 is upregulated by trypsin and contributes to leukocyte migration in acute pancreatitis

In acute pancreatitis, ICAM-1 is upregulated in various organs and contributes to the development of organ injury. To investigate the effects of pancreatic proteases on ICAM-1 expression and their role in the early process of leukocyte migration, human umbilical vein endothelial cells (HUVECs) were incubated with serum subjected to limited trypsin digestion and Wistar rats were injected with trypsin. Significant upregulation of membrane-bound ICAM-1 was seen on HUVECs incubated with trypsinated serum. Likewise, soluble ICAM-1 increased in the supernatant of HUVECs. Changes of membrane-bound ICAM-1 and soluble ICAM-1 were maximal with high concentrations of trypsin. HUVECs incubated with TNF-alpha (positive control) showed similar changes. In the pancreas and lungs of animals infused with trypsin, ICAM-1 and leukocyte sequestration were increased compared with controls. Reflecting the relevance of protease-induced ICAM-1 expression in leukocyte migration, leukocyte-endothelium interaction, as assessed by intravital microscopy, was markedly increased by trypsin. Inhibition of ICAM-1 ameliorated these changes significantly. In conclusion, trypsinated serum induces the upregulation of both membrane-bound ICAM-1 on endothelial cells and soluble ICAM-1. These changes contribute to the early steps of leukocyte migration in acute pancreatitis. The role of soluble ICAM-1 remains to be investigated.

Medical treatment of acute pancreatitis

Eighty percent of all cases of acute pancreatitis are linked etiologically to gallstone disease or caused by immoderate alcohol consumption. No specific causal treatment for acute pancreatitis exists. Early prognostic factors that indicate severe disease are three or more signs on organ failure scores according to Ranson, Imrie, or Acute Physiology and Chronic Health Evaluation (APACHE) 11, extrapancreatic complications of the disease, or the detection of pancreatic necrosis on CT scans. Elevated CRP levels above 130 mg/L can also predict a severe course of acute pancreatitis. The essential medical treatment for acute pancreatitis is the correction of hypovolemia. Moreover, relief of often severe visceral pain is a high priority. Prophylactic antibiotics should be restricted to patients with necrotizing pancreatitis, infected necrosis, or other infectious complications. Enteral nutrition has no adverse effect compared with parenteral nutrition during the course of acute pancreatitis, and is probably beneficial in regard to outcome.

The continuing challenge of early mortality in acute pancreatitis

Local networks may aid decision making

Trends in the management of severe acute pancreatitis: interventions and outcome

BACKGROUND

Severe acute pancreatitis (SAP) in the intensive care unit (ICU) is a complex and challenging problem. The aim of the present study was to identify trends in management of SAP patients admitted to a tertiary level ICU, and to relate these to changes in interventions and outcome.

METHODS

Patients admitted to the Department of Critical Care Medicine (DCCM), Auckland Public Hospital with SAP from 1988 to 2001 (inclusive) were identified from the DCCM prospective database, and data were extracted from several sources.

RESULTS

One hundred and twelve patients (men 69, women 43, mean age (+/-SD) 57.3 years +/- 14.3) were admitted with SAP to DCCM in the 13-year period. Aetiology was gallstones (42%), alcohol (29%), or idiopathic (29%). At admission to DCCM the median duration of symptoms was 7 days (range 1-100) and the mean (+/-SD) Acute Physiology and Chronic Health Evaluation II score was 19.9 +/- 8.2. Ninety-nine patients (88%) had respiratory failure and 79 (71%) had circulatory failure. The number of necrosectomies peaked between 1991 and 1995 (17/35 patients (49%) compared to 4/22 (18%) prior 1991; chi(2) = 6.90, P = 0.032). Abdominal decompression, enteral nutrition, percutaneous tracheostomy, and the use of stents in endoscopic retrograde cholangiopancreatography were introduced over the study period. The length of stay in DCCM did not alter (median 4 days, range 1-60) but there was a reduction in the length of hospital stay (median 36 days to 15 days; anova= 6.16, P = 0.046). The overall mortality was 31% (35/112) and did not alter over the study period.

CONCLUSIONS

SAP remains a formidable disease with a high mortality despite a number of changes in intensive care and surgical management.

Persistent organ failure during the first week as a marker of fatal outcome in acute pancreatitis

BACKGROUND

In predicted severe acute pancreatitis, many patients develop organ failure and recover without local complications, and mortality is only 14-30%. It has been suggested that half of patients with progressive early organ failure may die, but there are no data to relate death or local complications to duration of early (week 1) organ failure.

AIMS

To determine mortality rates in patients with transient (<48 hours) and persistent (>48 hours) early organ failure and to show whether persistent organ failure predicts death or local complications.

PATIENTS

A total of 290 patients with predicted severe acute pancreatitis previously studied in a trial of lexipafant, recruited from 78 hospitals through 18 centres in the UK.

METHOD

Manual review of trial database to determine: the presence of organ failure (Marshall score > or =2) on each of the first seven days in hospital, duration of organ failure, and outcome of pancreatitis (death, complications by Atlanta criteria).

RESULTS

Early organ failure was present in 174 (60%) patients. After transient organ failure (n = 71), outcome was good: one death and 29% local complications. Persistent organ failure (n = 103) was followed by 36 deaths and 77% local complications, irrespective of onset of organ failure on admission or later during the first week.

CONCLUSION

Duration of organ failure during the first week of predicted severe acute pancreatitis is strongly associated with the risk of death or local complications. Resolution of organ failure within 48 hours suggests a good prognosis; persistent organ failure is a marker for subsequent death or local complications.

Urinary trypsinogen activation peptide as a marker of severe acute pancreatitis

BACKGROUND

Trypsinogen activation peptide (TAP) may be an early marker of severe pancreatitis. Previous studies have included all patients with organ failure in the group with severe pancreatitis, although patients with transient organ failure may have a good prognosis. The aim of this study was to determine the value of urinary TAP estimation for prediction of severity of acute pancreatitis, and to validate use of several markers of prediction of severity against a new, stringent definition of severity.

METHODS

Patients with acute pancreatitis were recruited within 24 h of onset of symptoms. Urine and blood samples were collected for 24 h, and Acute Physiology And Chronic Health Evaluation (APACHE) II (24 h), Ranson (48 h) and Glasgow (48 h) scores were calculated. Severe acute pancreatitis was defined by the presence of a local complication or the presence of organ failure for more than 48 h.

RESULTS

Urinary TAP levels were significantly greater in patients with severe pancreatitis than in those with mild disease during the first 36 h of admission. The highest of three estimations of TAP in the first 24 h was as effective as APACHE II at 24 h in predicting severity. At 24 h after admission, urinary TAP was better than C-reactive protein (CRP) in predicting severity. The combination of TAP and CRP at 24 h allowed identification of high- and low-risk groups. The new definition of severity excluded 24 of 190 patients with transient organ failure; none of these patients died.

CONCLUSION

Use of TAP improved early prediction of the severity of acute pancreatitis. Organ failure that resolves within 48 h does not signify a severe attack of acute pancreatitis.

ICU management of severe acute pancreatitis

In intensive care medicine, severe acute pancreatitis (SAP) remains a very challenging disease with multiple complications and high mortality. The main pathophysiological mechanisms determining outcome are an uncontrolled systemic hyperinflammatory response early on and infection of pancreatic necrosis later on in the disease process. Despite a better understanding in recent years of the mechanisms and the mediators involved in the hyperinflammatory response, there is, as yet, no generally recognized specific treatment for this disease. Since early identification and aggressive treatment of associated organ dysfunction can have a major impact on outcome, early assessment of prognosis and severity is important. The evidence available indicates that patients with severe acute pancreatitis do not benefit from therapy with available antisecretory drugs or protease inhibitors. Supportive therapy, such as vigorous hydration, analgesia, correction of electrolyte and glycemia disorders, and pharmacological or mechanical support targeted at specific organs, is still the mainstay of therapy. In spite of meager evidence, prophylactic antibiotics with good penetration in pancreatic tissue are recommended in severe acute pancreatitis. Enteral nutrition via a nasojejunal tube has become the preferred route of feeding. Most patients with sterile necrosis do not benefit from surgical intervention. In patients with proven infection of pancreatic tissue, surgery is necessary. Percutaneous, radiological drainage techniques may eventually become an alternative form of drainage in selected patients.

Influence of molecule CD 11b blockade on the course of acute ceruleine pancreatitis in rats

Polymorphonuclear cells (PMN) activation is an essential step in acute pancreatitis (AP). We investigated the activation status of PMN, oxidative stress and pancreatic damage in early stage of experimental ceruleine pancreatitis in rats. The PMN action was modulated by monoclonal antibody CD 11b administration. The circulating WBC and polymorphonuclear cells count was reduced after AP induction. Chemiluminescence of whole blood PMN was remarkably reduced in AP group and increased after MoAb CD 11b administration. The CD 11b blockade significantly reduced the WBC infiltration and malondialdehyde (MDA) concentration within pancreatic gland. These data suggest that activated PMN are an important factor in early AP pathogenesis. Neutrophil aggregation within pancreatic gland modulated by monoclonal antibody CD11b contribute to the extent of injury during the early stage of ceruleine experimental pancreatitis in rats.

[Therapy of chronic pancreatitis]

Treatment of chronic pancreatitis is dependend on the stage of the disease and its complications. Pain therapy should be based on the knowledge of various causes of pain. In therapy of complications such as bile duct or pancreatic duct strictures interventional endoscopy is usually the first choice followed by surgery. Exocrine insufficiency is treated by porcine pancreatic extracts, endocrine insufficiency by insulin. One has to apply various imaging procedures such as sonography, MRCP, ERCP, endosonography, CT for exact diagnosis of complications and planning various therapeutic strategies. Pseudocysts may be drained via the transgastric, transduodenal, transpapillary or transcutaneous route. Distal prepapillary stenosis of the main pancreatic duct and bile duct stenoses can be drained by stents. Pancreatic duct stones can be desintegrated by shock waves and removed by endoscopy. Early diagnosis of pancreatic carcinoma as a potential complication of long standing inflammation of the pancreas remains an unsolved problem.

Plasma anti-inflammatory cytokines and monocyte human leucocyte antigen-DR expression in patients with acute pancreatitis

BACKGROUND

Immune suppression plays a role in the pathogenesis of acute pancreatitis. The purpose was to describe plasma anti-inflammatory cytokines and blood monocyte human leucocyte antigen (HLA)-DR expression, a cellular marker of immune suppression, in relation to clinical outcome in acute pancreatitis.

METHODS

We studied 74 patients with acute pancreatitis admitted within 72 h after symptom onset; 27 had mild disease and 47 severe disease, of whom 20 developed organ failure. Plasma cytokine concentrations and monocyte HLA-DR density were determined at admission and 1, 2, 3, 7, 14 and 21 days later.

RESULTS

The levels of interleukin-1 receptor antagonist, interleukin-6 and interleukin-10 correlated inversely to monocyte HLA-DR expression; each marker correlated with disease severity. Interleukin-4, -11 and -13 levels were low. Organ failure occurred at median 36 h (range 8 to 158) after admission and was predicted at admission by the combination of interleukin-6 and interleukin-10 with sensitivity of 95%, specificity of 88% and positive likelihood ratio of 7.6 (95% confidence interval 3.3 to 17). Patients with secondary infections had a lower proportion of HLA-DR positive monocytes than did controls at day 14 (median: 32% versus 65%; n = 7) and at day 21 (median: 49% versus 83%; n = 6), P < 0.05 each. In the organ failure group, HLA-DR expression did not differ between survivors and non-survivors.

CONCLUSIONS

Determining the severity of anti-inflammatory reaction at admission and monitoring the course of immune suppression provide a means for predicting clinical outcome in acute pancreatitis.

Role of inflammatory mediators in the pathophysiology of acute respiratory distress syndrome

Inflammatory response leading to organ dysfunction and failure continues to be the major problem after injury in many clinical conditions such as sepsis, severe burns, acute pancreatitis, haemorrhagic shock, and trauma. In general terms, systemic inflammatory response syndrome (SIRS) is an entirely normal response to injury. Systemic leukocyte activation, however, is a direct consequence of a SIRS and if excessive, can lead to distant organ damage and multiple organ dysfunction syndrome (MODS). When SIRS leads to MODS and organ failure, the mortality becomes high and can be more than 50%. Acute lung injury that clinically manifests as acute respiratory distress syndrome (ARDS) is a major component of MODS of various aetiologies. Inflammatory mediators play a key role in the pathogenesis of ARDS, which is the primary cause of death in these conditions. This review summarizes recent studies that demonstrate the critical role played by inflammatory mediators such as tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, platelet activating factor (PAF), IL-10, granulocyte macrophage-colony stimulating factor (GM-CSF), C5a, intercellular adhesion molecule (ICAM)-1, substance P, chemokines, VEGF, IGF-I, KGF, reactive oxygen species (ROS), and reactive nitrogen species (RNS) in the pathogenesis of ARDS. It is reasonable to speculate that elucidation of the key mediators in ARDS coupled with the discovery of specific inhibitors would make it possible to develop clinically effective anti-inflammatory therapy.

The role of platelet activating factor in a neonatal piglet model of necrotising enterocolitis

BACKGROUND AND AIMS

Necrotising enterocolitis (NEC) is a potentially devastating disorder of preterm infants but its aetiology remains unclear. The aim of these studies was to develop a neonatal piglet model for NEC and to then use the model to investigate the role of platelet activating factor (PAF) in its pathogenesis.

METHODS

Anaesthetised newborn piglets were divided into six groups: (i) controls, and groups subjected to (ii) hypoxia, (iii) lipopolysaccharide (LPS), (iv) hypoxia+LPS, (v) hypoxia+LPS and the PAF antagonist WEB 2170, and (vi) PAF. Arterial blood pressure (ABP), superior mesenteric artery blood flow (MBF), mesenteric vascular conductance (MVC), and arterial blood gases were recorded, and intestinal histology was evaluated.

RESULTS

Exposure to LPS, hypoxia+LPS, or PAF all caused haemorrhagic intestinal lesions associated with varying degrees of intestinal injury. PAF caused a significant initial decrease in both MVC and MBF whereas hypoxia+LPS caused a significant late reduction in ABP and MBF with a trend towards a decrease in MVC. The effects of hypoxia+LPS on both haemodynamic changes and intestinal injury were ameliorated by WEB 2170.

CONCLUSIONS

Administration of hypoxia and LPS or of PAF in the neonatal piglet induces haemodynamic changes and intestinal lesions that are consistent with NEC. These effects are ameliorated by prior administration of WEB 2170, indicating an important role for PAF in the pathogenesis of NEC.

Increasing age and APACHE II scores are the main determinants of outcome from pancreatic necrosectomy

BACKGROUND

The aim of this study was to identify factors associated with death after surgery in patients with extensive pancreatic necrosis.

METHODS

Sixty-four patients who underwent pancreatic necrosectomy between 1996 and 2002 were studied.

RESULTS

The median age was 60.5 (95 per cent confidence interval (c.i.) 57 to 64) years and 40 patients (62.5 per cent) were tertiary referrals. The initial median Acute Physiology And Chronic Health Evaluation (APACHE) II score was 9 (95 per cent c.i. 7.9 to 10.1) and there were 21 deaths (32.8 per cent). Twenty-eight patients (43.8 per cent) underwent minimally invasive retroperitoneal pancreatic necrosectomy (MIRP) and the remainder had open pancreatic necrosectomy (OPN); 44 (72.1 per cent) of 61 patients had infected pancreatic necrosis at the time of the first procedure. Seven patients who underwent MIRP died compared with 14 after OPN (P = 0.240). Patients who died were older than those who survived, with higher APACHE II scores at presentation, and before and after surgery (P = 0.001). Survivors had significantly longer times to surgery than those who died (P = 0.038). All 21 patients who died required intensive care compared with 26 of 43 survivors (P < 0.001). Thirty of 36 patients who had the OPN procedure required intensive care compared with only 17 of 28 patients who had MIRP (P = 0.042). Logistic regression analysis showed that only postoperative APACHE II score was an independent predictor of increased mortality (P = 0.031).

CONCLUSION

Advanced age and increasing APACHE II score, and a need for postoperative intensive care, were the most important predictors of outcome after pancreatic necrosectomy.

Combination of APACHE-II score and an obesity score (APACHE-O) for the prediction of severe acute pancreatitis

BACKGROUND

The advent of specific therapeutic or preventive treatments for severe acute pancreatitis creates a need to determine the risk of complications for each individual. Scoring systems used in acute pancreatitis identify groups of patients at risk of complications, but the pancreatitis-specific scores require 48 h of hospital admission to give full information. The APACHE-II score is useful within 24 h, but ignores simple clinical features, such as obesity, known to predict severity. The aim of this study was to evaluate a combination of the APACHE-II score with an obesity score in patients with acute pancreatitis, to predict severity using information available during the first 24 h of hospital admission.

METHODS

Data were collected prospectively from 186 consecutive patients with acute pancreatitis, to allow calculation of the APACHE-II score and body mass index (BMI). BMI was categorised as normal (score = 0), overweight (BMI 26-30: score = 1), or obese (BMI >30: score = 2). A logistic regression model was used to identify factors significantly associated with complications (Atlanta criteria; 104 complications in 60 patients).

RESULTS

Age, BMI and the acute physiology score independently predicted complications. Addition of the score for obesity to the APACHE-II score gave a composite score (APACHE-O) with greater predictive accuracy. At cut-off of >8, APACHE-O had sensitivity 82%, specificity 86%, positive predictive value 74%, negative predictive value 91% and overall accuracy 85%.

CONCLUSIONS

This study confirms that age, obesity and APACHE-II measured in the first 24 h of hospital admission can predict complications in acute pancreatitis. Combination of the APACHE-II and obesity scores by simple addition improved categorical prediction of severity (mild or severe) in patients with acute pancreatitis.

Natural history of organ failure in acute pancreatitis

The majority of deaths from acute pancreatitis are a consequence of multiple organ dysfunction syndrome (MODS). In order to influence the outcome of this condition, we need to have a better understanding of the natural history of acute pancreatitis, particularly when complicated by MODS. This paper reviews the recent literature dealing with the natural history of acute pancreatitis and the relationship between MODS, pancreatic necrosis and mortality.

Acute pancreatitis: treatment strategies

Acute pancreatitis is an acute painful abdominal disease of sudden onset that ranges from a mild and self-limited illness to a severe and severe life-threatening condition. In spite of decades of intensive research, there are no causal therapeutic options. Treatment relies on supportive treatment principles based on adequate volume replacement to compensate for fluid loss in the intraperitoneal space and analgesics for pain relief. In cases with acute pancreatitis predicted to have a severe course of the disease, antibiotic therapy is recommended to avoid infection of pancreatic necrosis. Despite a substantial set of clinical trials in favor of antibiotic treatment to reduce morbidity, there is no general consensus on the prophylactic antibiotic treatment. Adequate nutritional support is required for patients with severe acute pancreatitis and a protracted course of the disease. Enteral nutrition appears to be superior to enteral nutrition.

Modern phase-specific management of acute pancreatitis

The management of acute necrotizing pancreatitis has changed significantly over the past years. In contrast to the early surgical intervention of the past, there is now a strong tendency towards a more conservative approach. Initially, severe acute pancreatitis is characterized by the systemic inflammatory response syndrome. Early management is non-surgically and solely supportive. A specific treatment still does not exist. In cases of necrotizing disease, prophylactic antibiotics should be applied to reduce late septic complications. Today, more patients survive the first phase of severe pancreatitis due to improvements of intensive care medicine, thus increasing the risk of later sepsis. Pancreatic infection is the major risk factor with regard to morbidity and mortality in the second phase of severe acute pancreatitis. Whereas early surgery and surgery for sterile necrosis can only be recommended in selected cases, pancreatic infection is a well-accepted indication for surgical treatment in the second phase of the disease. Surgery should ideally be postponed until 4 weeks after the onset of symptoms, as necrosis is well demarcated at that time. Three surgical techniques can be performed with comparable results regarding mortality: necrosectomy combined with the (1) open packing technique, (2) planned staged relaparotomies with repeated lavage, or (3) closed continuous lavage of the retroperitoneum. However, the latter method seems to be associated with the lowest morbidity compared to the other approaches.

Compartmentalization of the inflammatory response during acute pancreatitis: correlation with local and systemic complications

Local and systemic inflammation has been implicated in the pathogenesis of acute pancreatitis and secondary multisystem organ failure. To assess the pro- and antiinflammatory response, the site of mediator production, and their route of diffusion, we sampled simultaneously ascites, thoracic lymph, and blood at the onset of end-organ dysfunction and for the following 6 days in 60 patients with acute pancreatitis. We used immunoassays to measure pro- and antiinflammatory cytokines and cell-based bioassays to assess the net pro- and antiinflammatory activity elicited by the biological fluids. Tumor necrosis factor-alpha and interleukin-1beta were detected in less than 15% of blood and lymph samples. Secondary pro- and antiinflammatory cytokines were found to be elevated early and throughout the sampling period in all compartments. Cytokine levels decreased from ascites to lymph to blood, suggesting a splanchnic origin. Prolonged diversion of ascites and lymph did not alter cytokine gradients, suggesting mediator transfer via the splanchnic blood circulation. Although a net proinflammatory activity ascribed to interleukin-1beta was detected in ascites, a net antiinflammatory activity was measured in virtually all lymph and blood samples, suggesting that the pancreas and the splanchnic area are sites of a proinflammatory response and that an early, dominant, and sustained antiinflammatory activity takes place in circulating compartments.

Inflammatory pancreatic diseases in older patients: recognition and management

The aging process influences and modifies the clinical picture and treatment modalities of inflammatory pancreatic diseases in elderly patients. The two major categories of inflammatory exocrine pancreatic diseases seen in the elderly are acute pancreatitis (AP) and chronic pancreatitis (CP). In elderly patients with AP, the presence of concomitant diseases affecting renal, hepatic and cardiopulmonary function make the early clinical assessment of the severity of AP inaccurate at the time of admission to hospital. In addition, the classical multifactorial scoring system routinely utilised in clinical practice to determine the severity of AP may overscore elderly patients because increasing age is associated with more points. Contrast-enhanced computed tomography is particularly useful in assessing the severity of AP and is required in all patients suspected with severe AP. It should be repeated after a certain time period to monitor the disease. The most important aspect of the management of elderly patients with severe AP is the prevention and treatment of systemic and local complications. Treatment of AP should address the removal of aetiological factor(s) and support of organ systems and hydroelectrolytic/caloric balance; specific treatments (antiproteases, antibacterials) should also be administered to patients with severe AP. Surgery is indicated mainly when infection occurs following pancreatic necrosis and/or fluid collection. However, in selected patients with a high anaesthetic risk, alternative, less invasive drainage options (percutaneous, endoscopic) should be considered. CP rarely occurs in older age, and it should be suspected based on clinical findings. The greatest challenge is the differentiation between CP and pancreatic cancer. Treatment of CP in the elderly should be directed at controlling the symptoms, by management of diabetes and exocrine insufficiency because pain and complications are rare in elderly patients with CP. Compliance with treatment should be periodically assessed if insulin and/or oral enzyme supplementation is required. Careful evaluation of nutritional status and its prompt correction is also important.

[Acute pancreatitis]

While interstitial acute pancreatitis usually takes a benign course, necrotizing acute pancreatitis takes a severe course, mainly because of severe local and systemic complications. After a quick diagnosis it is necessary to rapidly assess a degree of severity of the disease and thus the prognosis. The clinical picture and the result of imaging procedures do not always correspond. The management basically includes to treat pain as well as to administer fluid, electrolyte, protein and calories. In addition, systemic treatment of complications such as shock or respiratory and renal insufficiency--if occurring--is necessary. In case of pancreatic necrosis, prophylactic administration of pancreas-penetrable antibiotics is recommended to avoid infection. In the severely ill with infected pancreatic necrosis, surgery is the treatment of choice. In approximately 10% of all patients with alcohol-induced pancreatitis, there is a gradual transition to chronic pancreatitis.

Such stuff as dreams are made on: mediator-directed therapy in sepsis

Sepsis, a life-threatening disorder that arises through the body's response to infection, is the leading cause of death and disability for patients in an intensive care unit. Advances in the understanding of the complex biological processes responsible for the clinical syndrome have led to the identification of many promising new therapeutic targets, including bacterial toxins, host-derived mediators, and downstream processes such as coagulation and the endocrine response. Diverse therapies directed against these targets have shown dramatic effects in animal models; however, in humans, their impact has been frustratingly modest, and only one agent--recombinant activated protein C--has achieved regulatory approval. This review summarizes the approaches that have been evaluated in clinical trials, explores the reasons for the discordance between biological promise and clinical reality, and points to approaches that may lead to greater success in the future.

Pancreatitis

In the past decade, our understanding of the genetic basis, pathogenesis, and natural history of pancreatitis has grown strikingly. In severe acute pancreatitis, intensive medical support and non-surgical intervention for complications keeps patients alive; surgical drainage (necrosectomy) is reserved for patients with infected necrosis for whom supportive measures have failed. Enteral feeding has largely replaced the parenteral route; controversy remains with respect to use of prophylactic antibiotics. Although gene therapy for chronic pancreatitis is years away, our understanding of the roles of gene mutations in hereditary and sporadic pancreatitis offers tantalising clues about the disorder's pathogenesis. The division between acute and chronic pancreatitis has always been blurred: now, genetics of the disorder suggest a continuous range of disease rather than two separate entities. With recognition of pancreatic intraepithelial neoplasia, we see that chronic pancreatitis is a premalignant disorder in some patients. Magnetic resonance cholangiopancreatography and endoscopic ultrasound are destined to replace endoscopic retrograde cholangiopancreatography for many diagnostic indications in pancreatic disease.