A Multi-center Clinical Study Of The New Classification Of Acute Pancreatitis

Acute pancreatitisis a disease with a very variable clinical course and results. About20%of patients with acute pancreatitis experience a critical course. And the mortality ofthose with severe acute pancreatitis is10-30%. Currently, more than220,000patientswith acute pancreatitis were admitted to hospital in the United States each year. Andacute pancreatitis has been the most common gastrointestinal disease hospitalized. Andthe incidence is also growing, especially severe acute pancreatitis. Despite grea t progressin treatments for AP, the mortality rate remains high. However specific and effectivetreatments are partially reliant on accurate classification. Precise classification of acutepancreatitis severity is crucial to clinical works and research. In clinical works, accurateclassification has great value for elevating the severity, closely monitoring clinical courseand clinical management strategies. In clinical studies, it has great significance for theaccuracy of the patients included in clinical trials. The1992Atlanta classification dividedacute pancreatitis into2groups: mild ad severe. The2012revised Atlanta classificationdefined severity as3groups: mild, moderate and severe.ObjectiveOur researchaims to apply the above severity classification systems on aretrospectively enrolled, to perform a comparison between Atlanta1992and Atlanta2012with respect to these clinical outcomes. Due to the classification methodnot changed formild patients, so our study only compared with severe acute pancreatitis. In addition, weconsider severe acute pancreatitis (2012Atlanta classification) should be defined byinfection of pancreas and persistent organ failure together.MethodThe First Affiliated Hospital of Nanchang University and Changhai Hospital,Second Military Medical University supportedthe research. All of the patientshospitalizedin the two centers from1January2005to1December2012with a primarydiagnosis of severe AP defined by the1992Atlanta classification were retrospectivelyidentified.2154patients participated in this research.Then patients described abovereclassified with Atlanta2012, were stratified into two groups, moderate and severe.Primary outcomes of this study include organ failure, scores of severity, infection,mortality, intensive care unit (ICU) admission, need for surgical or invasive interventions,ICU length of stay, and hospital length of stay. ResultsThe most common etiology is biliary, accounting for60.4%. Compared to patientswith moderate AP (Atlanta2012), patients with severe AP (Atlanta2012) had higherscores in all score systems (P<0.00) except MCTSI (P=0.11). Incidence of organ failureis obviously higher, including multiple organ failure and single organ failure. Comparingsevere AP patients in Atlanta1992, severe patients in Atlanta2012had higher incidencein multiple organ failure (21.3%). Single respiratory failure was the most frequent organfailure both in moderate and severe patients. With regard to in-hospital mortality,comparison showed significant difference between moderate and severe patients (P<0.00)in the Atlanta2012. Patients in the severe group stayed in the ICU dramatically longer(P<0.00);and had an overall longer hospitalization (P<0.00). There was significantincrease in ICU admission, and need for blood purification, mechanical ventilation,enteral nutrition and interventions (P<0.00for all) in the Atlanta2012severe ascompared with moderate; and the mean duration of blood purification, mechanicalventilation, enteral nutrition was longer(P<0.00for all). For the need for surgical, testshowed no significant difference between the two groups. What’s more, pancreas-relatedinfection, organ failure and systemic inflammatory response syndrome are the riskfactors for hospital mortality.ConclusionOur study provides evidence that the2012Atlanta classification can better describerthe severity of acute pancreatitis, compared to the traditional Atlanta classification. Theclinical outcomes and prognosis of acute pancreatitis are very different betweenmoderate and severe patients. And we propose a new definition that severe group ofAtlanta2012is defined by the occurrence of persistent organ failure and/or infectedpancreatic necrosis. And we look forward to advancing prospective studies to validatethis definition.