Correlation between preoperative nutritional and immunological assessment and postoperative infections

The aim of this study was to clarify how much delayed hypersensitivity response (DHR) may improve the prognostic capacity of nutritional assessment (NA). NA and skin tests were performed at admission in 422 patients undergoing an elective general surgical procedure. Subjects with serum albumin ≤ 3 g/dl or total iron binding capacity ≤ 220 μg/dl or weight loss ≥ 10% with respect to usual body weight were classified as malnourished. Postoperative infection was found in 66 (29.0%) patients with an impairment in DHR and 26 (13.3%) normal responders (p <0.001). The incidence of postoperative complications was higher among the 197 malnourished patients (29.9%) than in the 225 well-nourished ones (14.6%) (p <0.001). An increasing risk of postoperative infections was found according to the number of altered nutritional parameters: the presence of one, two or three altered nutritional variables was associated with 1.8-fold, 2.9-fold and 4.3-fold increase in postoperative infection, respectively. A multiple logistic analysis showed that NA and DHR response offer an independent contribution in predicting postoperative infections. To clarify how much the predictive ability of NA may be improved by DHR, the relationship between DHR and postooperative complications was studied in the malnourished and in the well-nourished patients separately. The well-nourished subjects with a DHR depression had an incidence of postoperative septic complications not significantly higher than the well-nourished with normal skin tests. On the contrary the malnourished patients who showed an impairment in DHR had a significant higher rate of septic complications than those with normal skin tests (p <0.05). In conclusion DHR slightly improves the predictive capacity of NA, and a first approach to identify high risk patients could be the inexpensive, quick and available determination of nutritional status.