AP can be categorized into mild AP (MAP) to severe AP (SAP) and is a cause of acute abdomen. AP can be complicated with systemic inflammatory response syndrome and multiple organ failure, Diagnosis of AP and prediction of its severity is important for early management of the patients in order to decrease the rates of morbidity and mortality. Several parameters and scoring systems, such as Ranson criteria and the Acute Physiology and Chronic Health Evaluation II (APACHE II) score have been used to predict the severity of AP and its mortality. In this study the prognostic value of RDW in predicting mortality and severity of AP patients will be assessed .

Referred to Emergency Department of Imam Reza Hospital in with the diagnosis of acute pancreatitis were included. Patients with a history of hemoglobinopathy or hemoglobin less than 12 were excluded from the study because of the possibility of disruption of RDW. A checklist was prepared based on patients' demographic characteristics, clinical symptoms, and initial tests indicating severity of disease at admission. SPSS 16 were used for analyzing data.

Patients with acute pancreatitis were included in this study, including 64 men and 69 women (total 133). By using criteria of BICAP, 13 patient had severe AP and 120 patient with moderate AP. The final statistical analysis confirmed a significant relationship between the RDW value and severity of the disease. As well as patients with higher duration of hospital stay have greater RDW.

RDW is an easy to use and an inexpensive marker with a moderate prognostic value to predict severity in AP patients. Clinicians should be more alert when a patient with AP has an increased RDW.