Any stress, including that from a precise procedure, causes a remarkable release of adrenocorticotropic hormone (ACTH) from the anterior pituitary that, subsequently, directs the release of cortisol from the adrenal cortex. The circulating cortisol level remains elevated to two to five times the normal level for approximately 24 hours after the procedure52 and acts upon skeletal tissue to create about breakdown of skeletal muscle tissue proteins into amino acids for localized wound healing and for glucose production by the liver.
Concomitantly, epinephrine and norepinephrine are released and remain elevated for up to 48 hours, stimulating break down of liver glycogen with release of glucose for cellular energy needs throughout the immediate postoperative period.53 The upsurge in epinephrine suppresses release of insulin,54 glucagon concentrations rise,55 and the liver is stimulated to start gluconeogenesis to go back to preoperative levels and to aid the vitality requirements of the healing process. Additional reactions to surgery include alterations in water regulation mediated by release of antidiuretic hormone and aldosterone, which increases water reabsorption in the renal collecting ducts and increases sodium retention in the renal tubules, respectively.56,57 It’s believed that the release of the hormones is stimulated by signals from blood pressure– and osmolarity-sensitive receptors.53 This diminished capability to excrete water in early postoperative period results in temporary weight gain and a go back to normal blood volume.58 After the aforementioned events, the in-patient enters a metabolic transition amount of 1 or 2 days in which the human body begins to show from corticosteroid- and epinephrine-initiated breakdown to rebuilding and healing. During this time, shedding of the retained water is effected, while conserving nitrogen and potassium. The slow process of healing and regaining weight is now able to begin and is marked by protein synthesis, wound healing, buildup of muscle tissue, and increasing strength.53 Most of these processes occur with a reasonable amount of predictability in the adequately nourished adult patient. The procedure is imperiled, as could be the prognosis for full recovery, if the adult is elderly or malnourished.