Malnutrition is a frequent problem in critically ill patients that is associated with detrimental clinical outcomes. To provide adequate nutritional support, current studies focused mostly on the choice of delivery timing, formula selection and the route of administration, little attention was paid to malnutrition related to exocrine pancreatic insufficiency (EPI). In fact, malnutrition is also a major consequence of pancreatic exocrine insufficiency and pancreatic damage is commonly observed in critically ill patients without prior pancreatic diseases. Hence, EPI associated malnutrition should be concerned due to the high prevalence of pancreatic damage in critically ill patients. The aims of this study is to evaluate the incidence of EPI in critically ill adult patients and explore its potential risk factors. Moreover, the efficacy of pancreatic enzyme supplementation therapy on malnutrition in ICU patients with specific clinical characteristics will be investigated.