Nutritional screening for risk prediction in patients scheduled for abdominal operations

BACKGROUND: Increased risks related to surgery might reflect the nutritional status of some patients. Such a group might benefit from perioperative nutritional support. The purpose of this study was to identify the relative importance of nutritional risk screening along with established medical, anaesthetic and surgical predictors of postoperative morbidity and mortality. METHODS: This prospective observational study enrolled consecutive eligible patients scheduled for elective abdominal operations. Data were collected on nutritional variables (body mass index, weight loss, food intake), age, sex, type and extent of operation, underlying disease, American Society of Anesthesiologists grade and co-morbidities. A modified composite nutritional screening tool (Nutritional Risk Screening, NRS 2002) currently recommended by European guidelines was used. Relative complication rates were calculated with multiple logistic regression and cumulative proportional odds models. RESULTS: Some 653 patients were enrolled of whom 132 (20.2 per cent) sustained one or more postoperative complications. The frequency of this event increased significantly with a lower food intake before hospital admission. No other individual or composite nutritional variable provided comparable or better risk prediction (including NRS 2002). Other factors significantly associated with severe postoperative complications were ASA grade, male sex, underlying disease, extent of surgical procedure and volume of transfused red cell concentrates. CONCLUSION: In abdominal surgery, preoperative investigation of feeding habits may be sufficient to identify patients at increased risk of complications. Nutritional risk alone, however, is not sufficient to predict individual risk of complications reliably.