After reviewing our current knowledge of the metabolic response to major abdominal surgery, we present two new studies in which we have followed the changes in body composition, physiologic function, and psychological function for up to 1 year after major surgery. In the first study, 46 patients had changes in body composition, physiologic function, and psychological function measured perioperatively and again at intervals up to 1 year. There was an average loss of weight of 3000 grams Imaximum at 2 weeks/, and the tissue composition of this weight loss was composed of 1400 grams fat. 600 grams protein, and 1000 grams water. Normal body composition had returned to normal in most patients by 6 months. In the second study of 84 patients, deficits of skeletal muscle function and fatigue were found to be greatest at postoperative day 7. Most patients were back to preoperative levels of muscle function and fatigue 30 days after surgery, and nearly all had normal values 90 days after surgery. Based on these studies we outline our management program for the metabolic care of patients undergoing major abdominal surgery.Over many years surgeons have been interested in the early metabolic responses in patients undergoing major surgery particularly while the patients are still in the hospital, but it is only recently that long-term changes in metabolism, body composition. physiology, and psychological function have been studied over the weeks and months following surgery. Here we look at what is known about the metabolic changes brought about by the surgical procedure and show how these changes may persist for weeks and in some cases months before the patient is restored to full health. On this basis we set out a management program for the metabolic care of patients undergoing uncomplicated major elective surgery.
Metabolic Response to SurgeryCuthbertson [1] divided the metabolic response to injury into an early ebb phase, characterized by hypovolemia and subsequent sympathetic and adrenal response, and a later flow phase, during which the injured patient loses protein at an accelerated rate. The duration of the flow phase depends on the severity of the injury, and it is gradually replaced by a convalescent anabolic phase, during which the protein and energy stores lost in the early postinjury period are repleted (Table 1).
Ebb PhaseThe ebb phase is largely a result of hypovolemia, and it lasts until circulating blood volume is restored. The pale, clammy, tachycardiac patient visited by the surgeon soon after surgery is in the ebb phase. Hume and Egdahl [2] demonstrated the importance of the brain to the early endocrine response to injury. They disconnected an anesthetized animal's limb from its body, leaving only the sciatic nerve and femoral vessels. When they measured the level of corticosteroids in adrenal venous blood in response to a burn to the isolated limb they found an immediate rise; when the sciatic nerve was divided, this response did not occur. These same workers showed subsequently that the early hormone res...