Protein and carbohydrate absorptive efficiency of chronically malnourished and well-nourished patients during enteral feeding initiation.

To investigate the efficiency of protein and carbohydrate absorption, we studied malnourished and well-nourished subjects during the first 72 hours of tube feeding. We furthermore investigated whether differences in absorptive efficiency existed between malnourished patients with and without nongastrointestinal malignancy. Twenty-one subjects starting tube feeding without edema or major organ failure and not on antibiotics (well-nourished controls = 7; malnourished = 7; malnourished with nongastrointestinal malignancy = 7) received 50 kcal/hr Osmolite continuously for 72 hours. Twelve of these subjects completed an additional 48 hours of study where they received 125 kcal/hr continuously. We performed hydrogen breath tests to assess carbohydrate absorption and determined stool nitrogen content to assess protein absorption. We also measured frequency of defecation, stool weight, and stool moisture content. The results of these tests failed to reveal statistically significant differences between the three groups in terms of protein and carbohydrate absorption, as well as failed to demonstrate the presence of diarrhea. We conclude that patients receiving an isoosmolar diet who are malnourished, or malnourished with nongastrointestinal malignancy, absorb carbohydrate and protein as well as well-nourished patients during enteral hyperalimentation.