The effect of malnutrition on the metabolic response to surgery

The effect of previous malnutrition on the metabolic response to surgical h ysterectomy was investigated in adult female rats. Malnutrition was achieve d by feeding a 20 g protein/kg diet and restricting food intake to 50 % of normal. This dietary regimen was maintained for 3 weeks before surgery and for 4 d after surgery. Unoperated control rats were pair-fed with the hyste rectomized rats after surgery. Energy balance was measured by the comparati ve carcass technique and, in a second experiment, urinary N excretion was m easured. Surgery caused energy expenditure to increase by 37 % in nd libitu m-fed rats but in malnourished rats it increased by only 22 %. Urinary N ex cretion rose immediately after surgery. In the ad libitum-fed rats it was o n average 85 % greater in hysterectomized rats than controls for the first 3 d after surgery, whereas in the restricted rats it was 74 % greater on th e first day and not significantly elevated thereafter. Thus, malnutrition a ttenuated the metabolic response to surgery but did not abolish it complete ly.