PARENTERAL-NUTRITION IN OVERWEIGHT PATIENTS - ARE INTRAVENOUS LIPIDS NECESSARY TO PREVENT ESSENTIAL FATTY-ACID DEFICIENCY

Mobilization of endogenous adipose stores of linoleic acid prevents es sential fatty acid deficiency during fasting. However the dextrose pre sent in standard parenteral nutrition inhibits lipolysis and induces e ssential fatty acid deficiency unless lipids are administered. It has therefore become standard practice to administer at least 50 grams of intravenous fat per week to patients dependent on parenteral nutrition . This study was undertaken to determine whether hypocaloric feeding w ould permit sufficient mobilization of linoleic acid from adipose tiss ue stores to prevent essential fatty acid deficiency in overweight can cer patients receiving fat-free parenteral nutrition. Fifteen patients (mean 127% ideal body weight) received continuous infusions of hypoca loric, fat-free parenteral nutrition for 14 to 58 days (median 30 days ). Twelve patients lost weight during the study period, while no patie nt gained more than 5 kg. Changes in serum albumin were mild. Six pati ents required insulin for hyperglycemia; however; four of these patien ts had reductions in their insulin requirement despite continuation of parenteral nutrition. Fatty acid analyses were performed on plasma ph ospholipids from all 15 patients. No patient developed plasma evidence of essential fatty acid deficiency. In addition, no trend toward the development of essential fatty acid deficiency was observed with incre asing durations of fat-free parenteral nutrition. Conclusion: Overweig ht cancer patients can tolerate prolonged, continuous infusions of hyp ocaloric, fat-free parenteral nutrition without developing essential f atty acid deficiency. This approach appears to reduce both the toxicit y and the expense of parenteral nutrition.