EFFECT OF SEVERITY OF STRESS ON WHOLE-BODY PROTEIN KINETICS IN SURGICAL PATIENTS RECEIVING PARENTERAL-NUTRITION

A study was conducted to clarify the quantitative relationship between the alteration of protein metabolism and the severity of surgical str ess to further understand the mechanisms of body nitrogen losses in su rgical trauma. Twenty-one patients undergoing esophagectomy for esopha geal cancer (group E), and 22 undergoing gastrectomy or colorectal ope rations for gastric or colorectal cancer (Group GC) were studied. All patients were fed exclusively by parenteral nutrition (PN) providing 1 .5 g protein . kg(-1). d(-1) and 35 kcal . kg(-1). d(-1) before and af ter the operation. The measurements of whole-body protein turnover, sy nthesis, and breakdown were performed preoperatively and on postoperat ive days (PODs) 3 and 10. Urinary excretion of total nitrogen and tota l catecholamines was also measured. Urinary excretion of the total cat echolamines of group E was twice as high as that of group GC on the PO D 3 and well reflected the severity of surgical stress. Negative corre lation of nitrogen retention to urinary excretion of the total catecho lamines was also observed (r = 0.64; P < 0.01). The correlations betwe en the urinary excretion of the total catecholamines and the whole-bod y protein flux, synthesis, and breakdown were statistically significan t (r = 0.57, 0.27, and 0.57, respectively; P < 0.01 in all). Rate of e levation in breakdown according to the stress level was greater than t hat of synthesis. Consequently the progressive aggravation of nitrogen balance according to the severity of surgical stress was observed. (C ) Elsevier Science Inc.