Background: Malnutrition increases both morbidity and mortality in patients with acute pancreatitis (AP). However, few studies have investigated degree of malnutrition and their impact on patients’ outcomes. The objectives of this study is to investigate the incidence of malnutrition in hospitalized patients with AP and the effect of malnutrition on length of stay (LOS).

Materials and Methods: Data from all patients who were admitted with AP at King Chulalongkorn Memorial Hospital from April 2016 to July 2017 were collected.  The degree of malnutrition was evaluated using Nutritional Risk Screening (NRS) 2002 and Subjective global assessment (SGA). The effect of malnutrition on hospital LOS were calculated by Spearman’s correlation ( ).

Results: A total of 32 patients with AP were recruited. Twenty-two (68.8%), eight (21.9%) and two (9.4%) patients were classified as having mild, moderately severe and severe AP by revised Atlanta criteria 2012. Fourteen (43.8%) patients were categorized as at risk of malnutrition by NRS 2002 (score  3) and 10 (31.2%) patients were diagnosed with malnutrition by SGA (SGA class B and C). NRS 2002 score, but not SGA, significantly predicted LOS ( =0.5, p=0.003), which mean LOS (SD) of NRS score 1 to 4 were 3.5 (1.2), 8.6 (8), 8.2 (5.9) and 11.6 (5.7) days, respectively.

Conclusion: Malnutrition was common in patients admitted with AP. As for validated nutrition tools, NRS 2002 had better efficacy than SGA to predict LOS in AP patients.