AIM:To study clinical characteristics and management ofpatients with early severe acute pancreatitis (ESAP).METHODS:Data of 297 patients with severe acutepancreatitis (SAP) admitted to our hospital within 72 h afteronset of symptoms from January 1991 to June 2003 werereviewed for the occurrence and development of early severeacute pancreatitis (ESAP).ESAP was defined as presence oforgan dysfunction within 72 h after onset of symptoms.Sixty-nine patients had ESAP,228 patients without organdysfunction within 72 h after onset of symptoms had SAP.The clinical characteristics,incidence of organ dysfunctionduring hospitalization and prognosis between ESAP and SAPwere compared.RESULTS:Impairment degree of pancreas (Balthazar CTclass) in ESAP was more serious than that in SAP (5.31±0.68vs 3.68±0.29,P<0.01).ESAP had a higher mortality thanSAP (43.4% vs 2.6%,P<0.01),and a higher incidence ofhypoxemia (85.5% vs 25%,P<0.01),pancreas infection(15.9% vs7.5%,P<0.05),abdominal compartment syndrome(ACS) (78.3% vs 23.2%,P<0.01) and multiple organdysfunction syndrome (MODS)(78.3% vs 10.1%,P<0.01).In multiple logistic regression analysis,the main predisposingfactors to ESAP were higher APACHE Ⅱ score,Balthazar CTclass,MODS and hypoxemia.CONCLUSION:ESAP is characterised by MODS,severepathological changes of pancreas,early hypoxemia andabdominal compartment syndrome.Given the poor prognosisof ESAP,these patients should be treated in specializedintensive care units with special measures such as closesupervision,fluid resuscitation,improvement of hypoxemia,reduction of pancreatic secretion,elimination of inflammatorymediators,prevention and treatment of pancreatic infections.