Early assessment of pancreatic infections and overall prognosis in severe acute pancreatitis by procalcitonin (PCT): a prospective international multicenter study

[Procalcitonin-based algorithm. Management of antibiotic therapy in critically ill patients]

Sepsis is one of the most cost-intensive conditions of critically ill patients in intensive care medicine. Furthermore, sepsis is known to be the leading cause of morbidity and of mortality in intensive care patients. Early initiation of antibiotic therapy can significantly reduce mortality. The development of resistance of bacterial species against antibiotics is a compelling issue to reconsider indications and administration of antibiotic treatment. Adequate indications and duration of therapy are particularly important for the use of highly potent substances in the intensive care setting. Until recently no laboratory marker has been available to distinguish bacterial infections from viral or non-infectious inflammatory responses. However, procalcitonin (PCT) appears to be the first among a large array of inflammatory markers that offers this possibility. Regular procalcitonin measurements can significantly shorten the length of antibiotic therapy, show positive influence on antibiotic costs and have no adverse affects on patient outcome.

Biomarkers in the critically ill patient: procalcitonin

Infection and/or sepsis biomarkers should help to make the diagnosis and thus initiate therapy earlier, help to differentiate between infectious and sterile inflammation, allow the use of more-specific antimicrobials, shorten the time of antimicrobial use, and ideally identify distinct phenotypes that may benefit from specific adjunctive sepsis therapies. Procalcitonin (PCT) was proposed as a sepsis and infection marker more than 15 years ago. Meanwhile, PCT has been evaluated in various clinical settings. In this review the present use of PCT on the ICU and in critically ill patients is summarized, included it's role for diagnosis of severe sepsis and septic shock and antibiotic stewardship with PCT.

Infected pancreatic necrosis: Not necessarily a late event in acute pancreatitis

It is widely believed that infection of pancreatic necrosis is a late event in the natural course of acute pancreatitis. This paper discusses the available data on the timing of pancreatic infection. It appears that infected pancreatic necrosis occurs early in almost a quarter of patients. This has practical implications for the type, timing and duration of preventive strategies used in these patients. There are also implications for the classification of severity in patients with acute pancreatitis. Given that the main determinants of severity are both local and systemic complications and that they can occur both early and late in the course of acute pancreatitis, the classification of severity should be based on their presence or absence rather than on when they occur. To do otherwise, and in particular overlook early infected pancreatic necrosis, may lead to a misclassification error and fallacies of clinical studies in patients with acute pancreatitis.

Severe acute pancreatitis: advances and insights in assessment of severity and management

The patients with acute pancreatitis are at risk to develop different complications from ongoing pancreatic inflammation. Often, there is no correlation between the degree of structural damage to pancreas and clinical manifestation of the disease. The effectiveness of any treatment is related to the ability to predict severity accurately, but there is no ideal predictive system or biochemical marker. Severity assessment is indispensable to the selection of proper initial treatment in the management of acute pancreatitis. The use of multiparametric criteria and the evaluation of severity index permit us to select high-risk patients. Furthermore, contrast-enhanced computed tomographic scanning and contrast-enhanced MRI play an important role in severity assessment. The adoption of multiparametric criteria proposed together with morphological evaluation consents the formulation of a discreetly reliable prognosis on the evolution of the disease a few days from onset.

Reduction in antibiotic use through procalcitonin testing in patients in the medical admission unit or intensive care unit with suspicion of infection

We report an evaluation of the utility of serum procalcitonin (PCT) measurement as an additional diagnostic tool to support initiating or withholding antibiotics in clinical situations where there is a clinical suspicion of infection but the diagnosis is uncertain. During a six-month period, 99 patients on the medical admission unit (MAU) with suspected infection, and 42 patients on the intensive care unit (ICU) with clinical signs or physiological parameters suggesting possible new infection, had serum PCT concentration measured with the result available within 90min of the request. The test was initiated by the microbiology/infection team during clinical consultations to support the antibiotic decision. On the basis of low PCT values, antibiotics were withheld in MAU on 52 occasions and in ICU on 42 occasions. Patients were followed up prospectively for a week. There was neither progression of bacterial infection requiring antibiotics, nor complications or infection-related mortality in any patients who were denied antibiotics on either MAU or ICU. Without the PCT value it is likely that all of these patients would have received empirical antibiotics. Reduction in unnecessary antibiotic usage was made without any adverse effects on these patients and there was a clear reduction in antibiotic prescribing with cost reduction implications. PCT has the potential to become a valuable tool in antibiotic management.

Diagnostic and prognostic biomarkers of sepsis in critical care

Sepsis is a leading cause of mortality in critically ill patients. Delay in diagnosis and initiation of antibiotics have been shown to increase mortality in this cohort. However, differentiating sepsis from non-infectious triggers of the systemic inflammatory response syndrome (SIRS) is difficult, especially in critically ill patients who may have SIRS for other reasons. It is this conundrum that predominantly drives broad-spectrum antimicrobial use and the associated evolution of antibiotic resistance in critical care environments. It is perhaps unsurprising, therefore, that the search for a highly accurate biomarker of sepsis has become one of the holy grails of medicine. Procalcitonin (PCT) has emerged as the most studied and promising sepsis biomarker. For diagnostic and prognostic purposes in critical care, PCT is an advance on C-reactive protein and other traditional markers of sepsis, but is not accurate enough for clinicians to dispense with clinical judgement. There is stronger evidence, however, that measurement of PCT has a role in reducing the antibiotic exposure of critical care patients. For units intending to incorporate PCT assays into routine clinical practice, the cost-effectiveness of this is likely to depend on the pre-implementation length of an average antibiotic course and the subsequent impact of implementation on emerging antibiotic resistance. In most of the trials to date, the average baseline duration of the antibiotic course was longer than is currently standard practice in many UK critical care units. Many other biomarkers are currently being investigated. To be highly useful in clinical practice, it may be necessary to combine these with other novel biomarkers and/or traditional markers of sepsis.

Acute pancreatitis with an emphasis on infection

Acute pancreatitis is an inflammatory disease that is mild and self-limiting in about 80% of cases. However, severe necrotizing disease still has a mortality of up to 30%. Differentiated multimodal treatment concepts are needed for these patients, including a multidisciplinary team (intensivists, gastroenterologists, interventional radiologists, and surgeons). The primary therapy is supportive. Patients with infected pancreatic necrosis who are septic undergo interventional or surgical treatment, ideally not before the fourth week after onset of symptoms. This article reviews the pathophysiologic mechanisms of acute pancreatitis and describes clinical pathways for diagnosis and management based on the current literature and guidelines.

Gut barrier dysfunction in critically ill surgical patients with abdominal compartment syndrome

OBJECTIVES

This study investigated the effects of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) on gut barrier function in critically ill surgical patients.

METHODS

A prospective observational cohort study on patients with severe acute pancreatitis or abdominal sepsis admitted to an intensive care or high-dependency unit. Intra-abdominal pressure (IAP) and plasma levels of immunoglobulin G (IgG) and IgM antiendotoxin core antibodies (EndoCAb) and procalcitonin (ProCT) were measured serially.

RESULTS

Among 32 recruited patients, 24 (75%) and 8 patients (25%) developed IAH and ACS, respectively. The state of ACS was associated with significant reductions in plasma IgG EndoCAb (P = 0.015) and IgM EndoCAb (P = 0.016) and higher concentrations of plasma ProCT (P = 0.056) compared with absence of ACS. Resolution of IAH and ACS was associated with significant recovery of plasma IgG EndoCAb (P = 0.003 and P = 0.009, respectively) and IgM EndoCAb (P = 0.002 and P = 0.003, respectively) and reduction in plasma ProCT concentration (P = 0.049 and P = 0.019, respectively). Negative correlations were observed between IAP and plasma IgG EndoCAb (P = 0.003) and IgM EndoCAb (P = 0.002).

CONCLUSIONS

Intra-abdominal hypertension and ACS are associated with significantly higher endotoxin exposure and ProCT concentrations, suggestive of gut barrier dysfunction. Resolution of IAH and ACS is associated with evidence for recovery of gut barrier function.

Angiopoietin-2, a regulator of vascular permeability in inflammation, is associated with persistent organ failure in patients with acute pancreatitis from the United States and Germany

OBJECTIVES

Patients with severe acute pancreatitis (AP) typically develop vascular leak syndrome, resulting in hemoconcentration, hypotension, pulmonary edema, and renal insufficiency. Angiopoietin-1 (Ang-1) and 2 (Ang-2) are autocrine peptides that reduce or increase endothelial permeability, respectively. The aim of this study was to determine whether Ang-1 and/or Ang-2 levels are predictive biomarkers of persistent organ failure (>48 h) and prolonged hospital course.

METHODS

Banked serum from 28 patients enrolled in the Severity of Acute Pancreatitis Study at the University of Pittsburgh Medical Center (UPMC) and 58 controls was analyzed for Ang-1 and Ang-2 levels. Separately, serum from 123 patients and 103 controls at Greifswald University (GU), Germany was analyzed for Ang-2 levels. Angiopoietin levels were measured by enzyme-linked immunosorbent assay.

RESULTS

In all, 6 out of 28 UPMC patients (21%) and 14 out of 123 GU patients (13%) developed persistent organ failure and were classified as severe AP. Ang-2 was significantly higher on admission in patients who developed persistent organ failure compared with those who did not in UPMC (3,698 pg/ml vs. 1,001 pg/ml; P=0.001) and GU (4,945 pg/ml vs. 2,631 pg/ml; P=0.0004) cohorts. After data scaling, admission Ang-2 levels showed a receiver-operator curve of 0.81, sensitivity 90%, and specificity 67% in predicting persistent organ failure. In addition, Ang-2 levels remained significantly higher in severe AP compared with mild AP patients until day 7 (days 2-4: P<0.005; day 7: P<0.02). Ang-1 levels were not significantly different between mild and severe AP patients on admission.

CONCLUSIONS

Elevated serum Ang-2 levels on admission are associated with and may be a useful biomarker of predicting persistent organ failure and ongoing endothelial cell activation in AP.

Organ failure and infection of pancreatic necrosis as determinants of mortality in patients with acute pancreatitis

BACKGROUND & AIMS

There is no consistency between the individual studies in the literature on whether organ failure (OF) or infected pancreatic necrosis (IPN) is the main determinant of severity in acute pancreatitis. We aimed to statistically aggregate the available data and determine the pooled influence of OF and IPN on mortality in patients with acute pancreatitis.

METHODS

The search for relevant observational studies was undertaken in the MEDLINE, EMBASE, and Scopus electronic databases, as well as in the proceedings of major gastroenterology meetings. The summary estimates are presented as relative risk (RR) and 95% confidence interval (CI).

RESULTS

Fourteen studies comprising 1478 patients with acute pancreatitis were meta-analyzed. A total of 600 patients developed OF and 179 of them died (mortality, 30%); 314 patients developed IPN and 102 of them died (mortality, 32%). In a stratified analysis, patients with OF and IPN had a significantly higher risk of death in comparison with patients with OF and no IPN (RR = 1.94; 95% CI: 1.32-2.85; P = .0007) and in comparison with patients with IPN and no OF (RR = 2.65; 95% CI: 1.30-5.40; P = .0007).

CONCLUSIONS

In patients with acute pancreatitis, the absolute influence of OF and IPN on mortality is comparable and thus the presence of either indicates severe disease. The relative risk of mortality doubles when OF and IPN are both present and indicates extremely severe disease or critical acute pancreatitis.

Early hemoconcentration is associated with pancreatic necrosis only among transferred patients

OBJECTIVES

Studies evaluating hemoconcentration as a marker of necrosis in acute pancreatitis have reached different conclusions. The aim of this study was to determine the impact of transfer status on the accuracy of hemoconcentration for the prediction of pancreatic necrosis.

METHODS

We prospectively enrolled 339 patients in an observational cohort study from June 2005 to December 2007. Univariate and multivariate logistic regression analyses were used to evaluate the impact of transfer status on the relationship between hemoconcentration and necrosis. Accuracy for prediction of necrosis was measured by the area under the receiver operating characteristic curve.

RESULTS

Hemoconcentration was associated with increased risk of necrosis only among transferred patients (odds ratio [95% confidence limits], 3.6 [1.2, 10.8]). The area under the receiver operating characteristic curve for admission hematocrit for prediction of necrosis was 0.78 among the transferred patients versus 0.55 among those with primary admissions (chi2, P < 0.0001). Transferred patients had greater initial severity (median bedside index of severity in acute pancreatitis, 2 vs 1; P < 0.0001), were more likely to have hemoconcentration (44% vs 18%; chi2, P < 0.0001), and experienced increased necrosis (37.5% vs 3.6%; chi2, P < 0.0001) compared with primary admissions. After adjusting for sex, disease severity, fluid resuscitation, and transfer status, hemoconcentration was not associated with necrosis (Wald chi2, P = 0.14).

CONCLUSIONS

Transfer status is a confounder in the relationship between hemoconcentration and pancreatic necrosis.

Changes in blood polyamine levels in human acute pancreatitis

OBJECTIVE

Experimental studies have shown that pancreatic activation of polyamine catabolism occurs during the early stage of acute pancreatitis. Changes in pancreatic polyamines are reflected in the red blood cell (RBC) polyamine contents, correlating with the extent of pancreatic necrosis. The aim of this human study was to examine the changes in polyamine levels in the RBCs of patients with acute pancreatitis.

MATERIAL AND METHODS

Twenty-four patients with acute pancreatitis (7 alcoholic, 10 gallstone and 7 of unknown etiology) were recruited in the study. Eighteen patients with non-pancreatic acute abdominal diseases were included as controls, and 6 volunteers were studied as references. Blood samples were collected on admission and during hospitalization to assess polyamine levels. After clinical recovery, the patients revisited the clinic, and RBC polyamine levels were measured again. For comparison, plasma interleukin-6 (IL-6), IL-10 and C-reactive protein (CRP) were measured.

RESULTS

In acute pancreatitis patients, there was no difference in RBC polyamine levels on admission compared with those in controls or in volunteers. Putrescine levels on admission were higher in patients with pancreatic necrosis than in patients without necrosis, but there was no difference in spermidine and spermine levels. Patients with pancreatitis of unknown etiology had significantly higher levels of polyamines on admission and throughout hospitalization, but they also had more necrosis, which explained the difference in multivariate analysis. Spermidine and spermine levels increased after clinical recovery. RBC putrescine correlated with IL-6 and IL-10, and spermine correlated with CRP.

CONCLUSIONS

The results of this study suggest that RBC polyamines change in human acute pancreatitis in several respects, as has been previously observed in experimental pancreatitis.

Serum procalcitonin in systemic autoimmune diseases--where are we now?

OBJECTIVES

To review the current evidence regarding the value of measuring procalcitonin (PCT) levels in patients with systemic autoimmune diseases, with a focus on the evidence for diagnostic and analytical performance of this biomarker. A brief description of the pathophysiological basis of this biomarker is also included.

METHODS

Using PubMed from the National Library of Medicine, relevant English literature on PCT in patients with different systemic autoimmune diseases, from 1990 to 2009, was reviewed. The search used keywords referring to procalcitonin and systemic lupus erythematosus, antineutrophil cytoplasmic antibody-associated systemic vasculitis, Goodpasture syndrome, rheumatoid arthritis, and giant cell arteritis.

RESULTS

When used in the appropriate clinical setting, the measurement of serum PCT levels is valuable as a marker of severe systemic bacterial and fungal infections and sepsis. Information regarding plasma PCT levels in patients with active underlying systemic autoimmune diseases is limited, primarily from observational studies and case series, with considerable variability of patient characteristics and clinical settings. In the detection of systemic infection concomitant with autoimmune diseases, PCT had a diagnostic sensitivity of 53 to 100% and a specificity of 84 to 97% (depending on the selection criteria) and was superior to other inflammatory markers tested. Most of the studies used a semiquantitative test for PCT measurement (functional assay sensitivity <0.5 ng/mL), which can explain the low sensitivity of the test. PCT levels were not significantly affected by renal function abnormalities or immunosuppressive agents. Although high PCT levels commonly occurred with infection, elevated levels of PCT could be found in patients with vasculitis without evidence of infection, often correlated with high disease activity scores.

CONCLUSIONS

Significantly elevated PCT levels offer good specificity and sensitivity for systemic infection in patients with systemic autoimmune diseases, regardless of the use of corticosteroids or immunosuppressive agents. PCT measurement may add to diagnostic accuracy in patients with systemic autoimmune diseases who present with a febrile illness, especially when highly sensitive PCT assays and specific PCT cutoff ranges are used in a predefined clinical setting (reflecting the likelihood of infection versus an autoimmune disease flare). However, there are limitations when using this biomarker in patients with systemic autoimmune diseases. PCT levels should not replace the necessary extensive diagnostic workup, which should include a thorough history and physical examination, combined with appropriate immunological, microbiological, radiological, and histological data.

Serum profiles of C-reactive protein, interleukin-8, and tumor necrosis factor-alpha in patients with acute pancreatitis

Background-Aims. Early prediction of the severity of acute pancreatitis would lead to prompt intensive treatment resulting in improvement of the outcome. The present study investigated the use of C-reactive protein (CRP), interleukin IL-8 and tumor necrosis factor-α (TNF-α) as prognosticators of the severity of the disease. Methods. Twenty-six patients with acute pancreatitis were studied. Patients with APACHE II score of 9 or more formed the severe group, while the mild group consisted of patients with APACHE II score of less than 9. Serum samples for measurement of CRP, IL-8 and TNF-α were collected on the day of admission and additionally on the 2nd, 3rd and 7th days. Results. Significantly higher levels of IL-8 were found in patients with severe acute pancreatitis compared to those with mild disease especially at the 2nd and 3rd days (P = .001 and P = .014, resp.). No significant difference for CRP and TNF-α was observed between the two groups. The optimal cut-offs for IL-8 in order to discriminate severe from mild disease at the 2nd and 3rd days were 25.4 pg/mL and 14.5 pg/mL, respectively. Conclusions. IL-8 in early phase of acute pancreatitis is superior marker compared to CRP and TNF-α for distinguishing patients with severe disease.

Procalcitonin as a marker of severe bacterial infection in children in the emergency department

Procalcitonin, the prohormone of calcitonin, is a relatively new and innovative marker of bacterial infection that has multiple potential applications in the pediatric emergency department. In healthy individuals, circulating levels of procalcitonin are generally very low (<0.05 ng/mL), but in the setting of severe bacterial infection and sepsis, levels can increase by hundreds to thousands of fold within 4 to 6 hours. Although the exact physiologic function of procalcitonin has not been determined, the consistent response and rapid rise of this protein in the setting of severe bacterial infection make procalcitonin a very useful biomarker for invasive bacterial disease. In Europe, serum procalcitonin measurements are frequently used in the diagnosis and the management of patients in a variety of clinical settings. To date, the use of procalcitonin has been limited in the United States, but this valuable biomarker has many potential applications in both the pediatric emergency department and the intensive care unit. The intent of this article is to review the history of procalcitonin, describe the kinetics of the molecule in response to bacterial infection, describe the laboratory methods available for measuring procalcitonin, examine the main causes of procalcitonin elevation, and evaluate the potential applications of procalcitonin measurements in pediatric patients.

Assessment of severity of acute pancreatitis according to new prognostic factors and CT grading

The assessment of severity at the initial medical examination plays an important role in introducing adequate early treatment and the transfer of patients to a medical facility that can cope with severe acute pancreatitis. Under these circumstances, "criteria for severity assessment" have been prepared in various countries, including Japan, and these criteria are now being evaluated. The criteria for severity assessment of acute pancreatitis in Japan were determined in 1990 (of which a partial revision was made in 1999). In 2008, an overall revision was made and the new Japanese criteria for severity assessment of acute pancreatitis were prepared. In the new criteria for severity assessment, the diagnosis of severe acute pancreatitis can be made according to 9 prognostic factors and/or the computed tomography (CT) grades based on contrast-enhanced CT. Patients with severe acute pancreatitis are expected to be transferred to a specialist medical center or to an intensive care unit to receive adequate treatment there. In Japan, severe acute pancreatitis is recognized as being a specified intractable disease on the basis of these criteria, so medical expenses associated with severe acute pancreatitis are covered by Government payment.

Recent developments in acute pancreatitis

The incidence of acute pancreatitis (AP) has been increasing worldwide, but the major etiologies remain gallstones and alcohol. Several studies have reported that smoking is an independent risk factor for developing AP. Classification of AP has traditionally used the categories of mild and severe disease. However, a new intermediate category of moderately severe AP has been described with intermediate characteristics including a high incidence of local complications but a low mortality. Assessment criteria that can serve as early predictors of AP severity are often complex and not sufficiently accurate. However, several recently described criteria that rely on criteria such as the body mass index, physical findings, and simple laboratory measurements could prove useful if validated in large prospective studies. Many issues related to the therapy of AP are still unresolved. Although preliminary studies support the importance of early volume expansion for the treatment of acute pancreatitis, optimization of the amount and type of fluids will require further studies. Similarly, preliminary studies suggest that enteral nutrition might benefit patients with AP and could even be useful early in the course of disease. However, the timing and type of fluids as well as the intestinal infusion site require further study. Finally, issues related to the prophylactic use of antibiotics in patients with severe AP have not been resolved. While the process of clinical investigation moves slowly, progress has been made in clinical studies of AP.

Acute pancreatitis at the beginning of the 21st century: the state of the art

Acute pancreatitis is an acute inflammatory disease of the pancreas which can lead to a systemic inflammatory response syndrome with significant morbidity and mortality in 20% of patients. Gallstones and alcohol consumption are the most frequent causes of pancreatitis in adults. The treatment of mild acute pancreatitis is conservative and supportive; however severe episodes characterized by necrosis of the pancreatic tissue may require surgical intervention. Advanced understanding of the pathology, and increased interest in assessment of disease severity are the cornerstones of future management strategies of this complex and heterogeneous disease in the 21st century.

Prediction of mortality in acute pancreatitis: a systematic review of the published evidence

OBJECTIVE

In this review, we focus on studies that examined such prognostic indices in relation to predicting a fatal outcome from pancreatitis.

SUMMARY BACKGROUND DATA

Acute pancreatitis (AP) is a common emergency, and early identification of high-risk patients can be difficult. For this reason, a plethora of different prognostic variables and scoring systems have been assessed to see if they can reliably predict the severity of pancreatitis and/or subsequent mortality.

METHODS

All studies that focused on AP, including retrospective series and prospective trials, were retrieved and analysed for factors that could influence mortality. Articles that analysed factors influencing the severity of the disease or the manifestation of disease-related complications were excluded.

RESULTS

58 articles meeting the inclusion criteria were identified. Among the various factors investigated, APACHE II seemed to have the highest positive predictive value (69%). However, most prognostic variables and scores showed high negative predictive values but suboptimal values for positive predictive power.

CONCLUSIONS

Despite the proliferation of scoring systems for grading AP, none are ideal for the prediction of mortality. With the exception of the APACHE II, the other scores and indexes do not have a high degree of sensitivity, specificity and predictive values.

Early changes in blood urea nitrogen predict mortality in acute pancreatitis

BACKGROUND & AIMS

Routine laboratory tests that reflect intravascular volume status can play an important role in the early assessment of acute pancreatitis (AP). The objective of this study was to evaluate accuracy of serial blood urea nitrogen (BUN) versus serial hemoglobin (Hgb) measurement for prediction of in-hospital mortality in AP.

METHODS

We performed an observational cohort study on data from 69 US hospitals from January 2003 to December 2006. Repeated measures analysis was used to examine the relationship between early trends in BUN and Hgb with respect to mortality. Multivariate logistic regression was used to evaluate the impact of admission BUN, change in BUN, admission Hgb, and change in Hgb on mortality. Time-specific receiver operating characteristic curves and multivariable logistic regression compared accuracy of BUN, Hgb, and additional routine laboratory tests.

RESULTS

BUN levels were persistently higher among nonsurvivors than survivors during the first 48 hours of hospitalization (F-test; P < .0001). No such relationship existed for Hgb (F-test; P = .33). For every 5-mg/dl increase in BUN during the first 24 hours, the age- and gender-adjusted odds ratio for mortality increased by 2.2 (95% confidence limits, 1.8, 2.7). Of the 6 routine laboratory tests examined, BUN yielded the highest area under the concentration-time curve (AUC) for predicting mortality at admission (AUC = 0.79), 24 hours (AUC = 0.89), and 48 hours (AUC = 0.90). Combining admission BUN and change in BUN at 24 hours produced an AUC of 0.91 for mortality.

CONCLUSION

In a large, hospital-based cohort study, we identified serial BUN measurement as the most valuable single routine laboratory test for predicting mortality in AP.

Acute pancreatitis at the beginning of the 21st century: The state of the art

Acute pancreatitis is an acute inflammatory disease of the pancreas which can lead to a systemic inflammatory response syndrome with significant morbidity and mortality in 20% of patients. Gallstones and alcohol consumption are the most frequent causes of pancreatitis in adults. The treatment of mild acute pancreatitis is conservative and supportive; however severe episodes characterized by necrosis of the pancreatic tissue may require surgical intervention. Advanced understanding of the pathology, and increased interest in assessment of disease severity are the cornerstones of future management strategies of this complex and heterogeneous disease in the 21st century.

Efficacy of procalcitonin in the early diagnosis of bacterial infections in a critical care unit

Procalcitonin (PCT) is a marker of severe bacterial infections and organ failure due to sepsis. The purpose of the present study was to identify the appropriate cutoff level of PCT based on the findings of a blood culture and polymerase chain reaction (PCR). The PCT levels were measured in 116 patients in an intensive care unit who were suspected of having bacteremia, to examine its relationship with a blood culture or PCR. The PCT levels were significantly high in patients with bacteremia, but they were also moderately high in some patients who were positive for fungus DNA. The area under the curve was significantly higher for PCT than for C-reactive protein. The appropriate cutoff values of PCT for bacteremia were 0.38 microg/L for the high negative predictive value and 0.83 microg/L for the high positive predictive value. Procalcitonin was slightly related to mortality, and the combination of a blood culture and PCR was thus found to increase the sensitivity for mortality. These findings suggest that PCT is useful for the diagnosis of bacteremia and that the diagnostic value of PCT in combination a with blood culture and PCR for bacterial infection or mortality further increases.

Plasma concentrations of high-mobility group box protein 1, soluble receptor for advanced glycation end-products and circulating DNA in patients with acute pancreatitis

AIMS

High-mobility group box protein 1 (HMGB1), a late-acting proinflammatory cytokine, is secreted actively by inflammatory cells, and released passively from necrotic cells. From the aspect that both inflammation and necrosis are involved in the pathogenesis in acute pancreatitis, the aim of the study was a joint investigation of the plasma concentrations of HMGB1, its soluble receptor for advanced glycation end-products (sRAGE), and the circulating DNA as a marker of cell death.

METHODS

62 patients with acute pancreatitis (30 mild, 32 severe), 20 patients with sepsis, and 20 healthy controls were enrolled in the study. HMGB1 and sRAGE plasma levels were measured by means of ELISA. Plasma DNA concentrations were estimated by real-time quantitative PCR for the beta-globin gene.

RESULTS

The circulating HMGB1 level was significantly higher in patients with severe acute pancreatitis (13.33 +/- 2.11 ng/ml) than in healthy controls (0.161 +/- 0.03 ng/ml) or than in patients with mild pancreatitis (2.64 +/- 0.185 ng/ml). The plasma concentration of sRAGE was highest in patients with sepsis (2,210 +/- 252 pg/ml), while the levels of sRAGE correlated inversely with that of HMGB1 in patients with acute pancreatitis. The plasma DNA level was significantly elevated in patients with severe acute pancreatitis (2,206 +/- 452 ng/ml).

CONCLUSION

A complex study of the plasma levels of HMGB1, sRAGE and circulating DNA can be informative in evaluations of acute pancreatitis with different levels of severity.

The value of procalcitonin at predicting the severity of acute pancreatitis and development of infected pancreatic necrosis: systematic review

BACKGROUND

Many studies have evaluated serum levels of procalcitonin (PCT) as a predictor in the development of severe acute pancreatitis (SAP) and infected pancreatic necrosis (IPN). This study assesses the value of PCT as a marker of development of SAP and IPN.

METHODS

Medline, Web of Science, the Cochrane clinical trials register, and international conference proceedings were searched systematically for prospective studies, which evaluated the usefulness of PCT as a marker of SAP and IPN. The sensitivity, specificity, and diagnostic odds ratios (DORs) were calculated for each study, and the study quality and heterogeneity among the studies were evaluated.

RESULTS

Twenty-four of 59 studies identified were included in data extraction. The sensitivity and specificity of PCT for development of SAP were 0.72 and 0.86, respectively (area under the curve [AUC] = 0.87; DOR = 14.9; 95% confidence interval [CI] = 5.6-39.8), albeit with a significant degree of heterogeneity (Q = 28.56, P < .01). The sensitivity and specificity of PCT for prediction of infected pancreatic necrosis were 0.80 and 0.91 (AUC = 0.91; DOR = 28.3; 95% CI = 13.8-58.3) with no significant heterogeneity (Q = 7.83, P = .18). No significant heterogeneity was observed among the studies when only higher quality studies (AUC = 0.91; DOR = 30.7; 95% CI = 10.7-87.8) or studies that used a cutoff PCT level >0.5 ng/mL (AUC = 0.88, 32.8; 95% CI = 10.1-106.6) were included.

CONCLUSION

Serum measurements of PCT may be valuable in predicting the severity of acute pancreatitis and the risk of developing infected pancreatic necrosis.

Soluble E-cadherin: an early marker of severity in acute pancreatitis

BACKGROUND/AIMS

At present, there is no simple test for predicting severity in acute pancreatitis. We investigated the use of an assay of soluble E-cadherin (sE-cadherin).

METHODS

Concentrations of sE-cadherin, from 19 patients with mild acute pancreatitis, 7 patients with severe acute pancreatitis, 11 patients with other acute gastrointestinal pathologies, and 12 healthy subjects were measured using a commercially available sandwich ELISA kit based on two monoclonal antibodies specific to the extracellular fragment of human E-cadherin. Measurements were made at 12 hours or less from onset of pain and also at 24 and 48 hours after onset of pain.

RESULTS

Mean (standard deviation) concentration of sE-cadherin in patients with severe acute pancreatitis at <12 hours was 17780 ng/mL (7853), significantly higher than that of healthy volunteers 5180 ng/mL (1350), P = .0039, patients with other gastrointestinal pathologies 7358 ng/mL (6655), P = .0073, and also significantly higher than that of patients with mild pancreatitis, 7332 ng/mL (2843), P = .0019.

DISCUSSION

Serum sE-cadherin could be an early (within 12 hours) objective marker of severity in acute pancreatitis. This molecule warrants further investigation in the form of a large multicentre trial.

Prevention, detection, and management of infected necrosis in severe acute pancreatitis

The management of infected peripancreatic or pancreatic necrosis in patients with severe pancreatitis has changed considerably in recent years. This review discusses the recent literature on prevention, detection, and management of infected necrosis. Though antibiotics, probiotics, and enteral nutrition have been tried to prevent infected necrosis, only enteral nutrition has consistently proven to be effective. Antibiotics and probiotics have not shown a consistent beneficial effect on outcome. Enteral nutrition reduced infectious complications and mortality in severe pancreatitis, compared with parenteral nutrition. The detection of infection of pancreatic necrosis is important for clinical decision making. Fine-needle aspiration may be used to confirm suspected infection, but if its results will not change clinical decisions, it should be omitted, as it may even introduce infection. Minimally invasive surgical, radiologic, or endoscopic intervention is increasingly being applied. In the absence of level 1 evidence, local expertise dictates which type of intervention is applied.

Risk assessment in acute pancreatitis

BACKGROUND

Acute pancreatitis has a variable natural history and in a proportion of patients is associated with severe complications and a significant risk of death. The various tools available for risk assessment in acute pancreatitis are reviewed.

METHODS

Relevant medical literature from PubMed, Ovid, Embase, Web of Science and The Cochrane Library websites to May 2008 was reviewed.

RESULTS AND CONCLUSION

Over the past 30 years several scoring systems have been developed to predict the severity of acute pancreatitis in the first 48-72 h. Biochemical and immunological markers, imaging modalities and novel predictive models may help identify patients at high risk of complications or death. Recently, there has been a recognition of the importance of the systemic inflammatory response syndrome and organ dysfunction.

Changes in serum procalcitonin and C-reactive protein following antimicrobial therapy as a guide to antibiotic duration in the critically ill: a prospective evaluation

Serial procalcitonin is reported to be useful to titrate duration of antibiotic therapy in the non critically ill patient with pneumonia. The aim of this study was to examine the relationship between antibiotic therapy and serial serum procalcitonin concentrations in a cohort of critically ill septic patients and examine for any differences between culture positive (CP) and culture negative (CN) sepsis. Seventy-five critically ill patients with suspected sepsis were enrolled in this prospective observational study. Serial procalcitonin and C-reactive protein assays were measured on days one, three, five, seven, 10 and 14. The mean duration of antibiotic therapy was similar in the two groups (10.4 +/- 5.1 (CP) vs. 8.4 +/- 5.1 (CN) days, P = 0.09). Serum procalcitonin concentrations were significantly higher at baseline in the CP than the CN group (14.9 +/- 22.9 vs. 6.8 +/- 21.5 ng/ml, P = 0.04). During the study period, serum concentrations of procalcitonin and C-reactive protein declined in both groups. Serum procalcitonin consistently remained higher in the CP group (P < 0.05) and did not return to normal values. In the CN group, procalcitonin concentrations fell below 0.5 only on day 10. There was no significant difference in C-reactive protein profile between the two groups. Four patients in the CP group (11%) had relapse of sepsis. The mean procalcitonins in the relapsed subgroup were lower than those in the remission subgroup (P = 0.02). Therapy for proven or presumed infections was associated with declining serum procalcitonin and C-reactive protein in critically ill septic patients. The marked variability and overlap in plasma profile of these markers between CP and CN sepsis makes it difficult to define a nadir plasma concentration at which one can recommend discontinuation of antibiotic therapy.

Conservative approach in the management of severe acute pancreatitis: eight-year experience in a single institution

INTRODUCTION

Recognition of severe acute pancreatitis (SAP), intensive care, shifting away from early surgical treatment, and monitoring of the intra-abdominal pressure (IAP) is important in the management of SAP. The aim of our study was retrospective evaluation and critical assessment of the experience with SAP management protocol involving new strategy in the university hospital.

METHODS

Protocols of 274 SAP patients treated in our institution during the last eight years were reassessed. APACHE II, CRP and SOFA score, IAP, pulmonary complications, ventilatory support and infection rate were evaluated. The success of the conservative treatment, surgical interventions and mortality was analysed comparing period 1 from 1999 to 2002 and period 2 from 2003 to 2006.

RESULTS

More patients with necrotising SAP were treated in period 2. The average CRP and SOFA score was higher in period 2, p=0.018; p=0.011. A total of 139 patients underwent continuous veno-venous haemofiltration (CVVH) as a component of fluid resuscitation and IAP control. Application of CVVH increased in period 2, p<0.005. Only 5-8% of patients were managed with ventilatory support. The overall infection rate decreased in period 2 comprising 21%, p<0.005. Success rate of the conservative therapy reached 69% in period 2, p<0.01. Surgical treatment was performed in 41% of patients in period 1 vs. 19% in period 2, p<0.001. Overall mortality was 19%, with a reduction to 12% in year 2006.

CONCLUSION

The conservative protocol-based approach is a rational treatment strategy for the management of SAP and can be successfully implemented in the setting of the university hospital.

Progress in medical management of intra-abdominal infection

PURPOSE OF REVIEW

Intra-abdominal infection management remains debated and evidence-based recommendations are often lacking despite numerous studies. These controversies are mainly explained by the limited number of powered and well designed randomized controlled trials. This review focuses on recent studies on antibiotic therapy for intra-abdominal infections and in particular for the management of severe acute pancreatitis.

RECENT FINDINGS

For community-acquired intra-abdominal infection, early source control and antibiotic selection are well codified. In severe forms, every hour of delay between shock and antibiotherapy initiation reduces hospital survival. Antibiotics dose adjustment and continuous intravenous administration are suggested in critically ill patients and for difficult-to-treat pathogens. Shorter antibiotic treatment duration seems to offer similar clinical cure rates compared with prolonged therapy and could reduce emergence of resistance. For multidrug-resistant bacteria, the newly developed agents indications need to be better defined. In severe acute pancreatitis, antibiotic prophylaxis does not prevent necrosis infection nor does it reduce surgery requirement or mortality. Antibiotics should be given on demand. Infectious complications in pancreatitis are not reduced by probiotic prophylaxis and mortality is increased.

SUMMARY

There is a growing evidence to support early, dose-adjusted, antimicrobial therapy in severe intra-abdominal infection, together with shorter treatment duration if source control is achieved. This could reduce emergence of resistance without affecting clinical cure rates. In severe acute necrotizing pancreatitis, antibiotic and probiotic prophylaxis to reduce infection or mortality should be avoided.

The increase of endothelial progenitor cells in the peripheral blood: a new parameter for detecting onset and severity of sepsis

Sepsis is a clinical syndrome characterized by non-specific inflammatory response with evidence of profound changes in the function and structure of endothelium. Recent evidence suggests that vascular maintenance, repair and angiogenesis are in part mediated by recruitment from bone marrow (BM) of endothelial progenitor cells (EPCs). In this study we were interested in whether EPCs are increasingly mobilized during sepsis and if this mobilization is associated with sepsis severity. Our flow cytometry data demonstrate that in the CD34+ cell gate the number of EPCs in the blood of patients with sepsis had a four-fold increase (45 +/- 4.5% p < 0.001) compared to healthy controls (12 +/- 3.6%) and that this increase was already evident at 6 hours from diagnosis (40.6 +/- 4.2 percent), reaching its maximum at 72 hours. Also the percentage of cEPCs identified in the patients with sepsis (35 +/- 4.6% of the CD34+ cell) was statistically different (p < 0.001) compared to that found in the blood of patients with severe sepsis (75 +/- 4.9%). In addition, we proved that at six hours after sepsis diagnosis, VEGF, CXCL8 and CXCL12 serum levels were significantly higher in septic patients compared to healthy volunteers 559 +/- 82.14 pg/ml vs 2.9 +/- 0.6 (p < 0.0001), 189.8 +/- 67.3 pg/ml 15 vs 11.9 +/- 1.6 (p = 0.014) and 780.5 +/- 106.5 pg/ml; vs 190.2 +/- 71.4 (p < 0.001). Our data suggest that the cEPC evaluation in peripheral blood, even at early times of diagnosis, in patients with sepsis can be envisaged as a valuable parameter to confirm diagnosis and suggest further prognosis.

Pro/Con debate: is procalcitonin useful for guiding antibiotic decision making in critically ill patients?

You are concerned about the escalating use of antibiotics in your intensive care unit (ICU). This has put a strain on the ICU budget and is possibly resulting in the emergence of resistant bacteria. You review the situation with your team and one suggestion is to consider using biomarkers such as procalcitonin to better guide appropriate antibiotic decision making.

Severe acute pancreatitis: Pathogenetic aspects and prognostic factors

Approximately 20% of patients with acute pancreatitis develop a severe disease associated with complications and high risk of mortality. The purpose of this study is to review pathogenesis and prognostic factors of severe acute pancreatitis (SAP). An extensive medline search was undertaken with focusing on pathogenesis, complications and prognostic evaluation of SAP. Cytokines and other inflammatory markers play a major role in the pathogenesis and course of SAP and can be used as prognostic markers in its early phase. Other markers such as simple prognostic scores have been found to be as effective as multifactorial scoring systems (MFSS) at 48 h with the advantage of simplicity, efficacy, low cost, accuracy and early prediction of SAP. Recently, several laboratory markers including hematocrit, blood urea nitrogen (BUN), creatinine, matrix metalloproteinase-9 (MMP-9) and serum amyloid A (SAA) have been used as early predictors of severity within the first 24 h. The last few years have witnessed a tremendous progress in understanding the pathogenesis and predicting the outcome of SAP. In this review we classified the prognostic markers into predictors of severity, pancreatic necrosis (PN), infected PN (IPN) and mortality.

Necrotizing pancreatitis: diagnosis and management

Necrotizing pancreatitis is a severe disease characterized by gland necrosis and a destructive systemic inflammatory response. Early management involves aggressive resuscitative and supportive measures. Outcomes are primarily determined by the presence of late secondary bacterial infection of the necrotic gland. Early empiric antibiotics and late surgical necrosectomy in the appropriate setting are the keys to managing these sick patients. With appropriate management, mortality can be minimized and long-term quality of life may be restored.

Markers for predicting severity and progression of acute pancreatitis

Several tools have been developed for severity stratification in acute pancreatitis. They include single biochemical markers, imaging methods, and complex scoring systems, all of which aim at an early detection of severe acute pancreatitis to optimise monitoring and treatment of patients as early as possible. Among single biochemical markers, C-reactive protein (CRP) remains the most useful. Despite its delayed increase, peaking not earlier than 72 h after the onset of symptoms, it is accurate and widely available. Many other markers have been evaluated for their usefulness, and for some of them very promising data could be shown. Among them interleukin 6 seems to be the most promising parameter for use in clinical routine. For the detection of pancreatic infection, procalcitonin is the most sensitive, and can be used as an indicator for the need for fine-needle aspiration of pancreatic necrosis. Regarding imaging, contrast-enhanced computed tomography is still the reference method for the detection of necrotising acute pancreatitis. Pancreatitis-specific scoring systems have been shown to be of value for the prediction of severity and progression of acute pancreatitis, but cannot be applied any earlier than 48 h after admission to hospital. The APACHE-II score has not been developed specifically for acute pancreatitis and is rather complex to assess, but has been proven to be an early and reliable tool. Indication, timing and consequences of the methods applied need to be carefully considered and incorporated into clinical assessments to avoid costs and harm to the patient.

Early nasogastric enteral nutrition for severe acute pancreatitis: a systematic review

AIM

To evaluate the effectiveness and safety of early nasogastric enteral nutrition (NGEN) for patients with severe acute pancreatitis (SAP).

METHODS

We searched Cochrane Central Register of Controlled Trials (Issue 2, 2006), Pub-Medline (1966-2006), and references from relevant articles. We included randomized controlled trials (RCTs) only, which reported the mortality of SAP patients at least. Two reviewers assessed the quality of each trial and collected data independently. The Cochrane Collaboration's RevMan 4.2.9 software was used for statistical analysis.

RESULTS

Three RCTs were included, involving 131 patients. The baselines of each trial were comparable. Meta-analysis showed no significant differences in mortality rate of SAP patients between nasogastric and conventional routes (RR = 0.76, 95% CI = 0.37 and 1.55, P = 0.45), and in other outcomes, including time of hospital stay (weighted mean difference = -5.87, 95% CI = -20.58 and 8.84, P = 0.43), complication rate of infection (RR = 1.41, 95% CI = 0.62 and 3.23, P = 0.41) or multiple organ deficiency syndrome (RR = 0.97, 95% CI = 0.27 and 3.47, P = 0.97), rate of admission to ICU (RR = 1.00, 95% CI = 0.48 and 2.09, P = 0.99) or conversion to surgery (RR = 0.66, 95% CI = 0.12 and 3.69, P = 0.64), as well as recurrence of re-feeding pain and adverse events associated with nutrition.

CONCLUSION

Early NGEN is a breakthrough in the management of SAP. Based on current studies, early NGEN appears effective and safe. Since the available evidence is poor in quantity, it is hard to make an accurate evaluation of the role of early NGEN in SAP. Before recommendation to clinical practice, further high qualified, large scale, randomized controlled trials are needed.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (>50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (> 50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

New advances in pancreatic surgery

PURPOSE OF REVIEW

New understanding of the dynamic of acute pancreatitis, the clinical impact of local pathology in chronic pancreatitis and cystic neoplastic lesions bearing high potential for malignant transformation has changed the management of pancreatic diseases.

RECENT FINDINGS

In acute pancreatitis, risk factors independently determining outcome in severe acute pancreatitis are early and persistent multiorgan failure, infected necrosis and extended sterile necrosis. The management of severe acute pancreatitis is based on early intensive-care treatment and late surgical debridement. In chronic pancreatitis, recent data from randomized controlled clinical trials have demonstrated duodenum-preserving pancreatic head resection with an inflammatory mass of the head as superior to pylorus-preserving Whipple resection. Cystic neoplasms are local lesions of the pancreas with high malignant potential. Local organ-preserving resection techniques have been applied with low morbidity and mortality, replacing a Whipple-type resection. Resection of pancreatic cancer is ineffective to cure patients. After an R0-resection, a significant survival benefit has been achieved when adjuvant chemotherapy has additionally been applied.

SUMMARY

New knowledge about the nature of inflammatory diseases, cystic neoplastic lesions and malignant pancreatic tumours has changed the indication for surgical treatment and the application of organ-preserving surgical techniques.

Predicting severity of acute pancreatitis

Severity stratification is a critical issue in acute pancreatitis that strongly influences diagnostic and therapeutic decision making. According to the widely used Atlanta classification, "severe" disease comprises various local and systemic complications that are associated with an increased risk of mortality. However, results from recent clinical studies indicate that these complications vary in their effect on outcome, and many are not necessarily life threatening on their own. Therefore, "severe," as defined by Atlanta, must be distinguished from "prognostic," aiming at nonsurvival. In the first week after disease onset, pancreatitis-related organ failure is the preferred variable for predicting severity and prognosis because it outweighs morphologic complications. Contrast-enhanced CT and MRI allow for accurate stratification of local severity beyond the first week after symptom onset. Among the biochemical markers, C-reactive protein is still the parameter of choice to assess attack severity, although prognostic estimation is not possible. Other markers, including pancreatic protease activation peptides, interleukins-6 and -8, and polymorphonuclear elastase are useful early indicators of severity. Procalcitonin is one of the most promising single markers for assessment of major complications and prognosis throughout the disease course.