The Surgically Induced Stress Response

By Stine Thestrup Hansen, RN, PhD, Postdoc in Nursing

Postoperative nursing is necessary to monitor the patient’s condition so that complications are prevented or detected early, and to minimize the surgical stress response.

Following surgical or accidental trauma, the nervous system activates the stress response by sending impulses from the injured site to the hypothalamus. The stress response to surgery is characterized by increased secretion of pituitary hormones and activation of the sympathetic nervous system. The endocrine system response includes:

The hypothalamus both directly and indirectly coordinates the complex hormonal stress response. Corticotrophin-releasing hormone (CRH), secreted in response to surgical stress, activates the hypothalamic–pituitary–adrenal (HPA) axis cascade and its metabolic consequences. Corticotrophin-releasing hormone stimulates the anterior pituitary gland to secrete adrenocorticotropic hormone (ACTH). Adrenocorticotropic hormone acts on cells in the zona fasciculata of the adrenal cortex to promote glucocorticoid (cortisol) secretion. Elevations of cortisol, glucagon, catecholamines, and a host of inflammatory cytokines, also exacerbate the stress response to surgery (Figure 2).

Immediately after surgery, ultradian pulses in ACTH and cortisol both increase. Adrenocorticotropic hormone concentrations return to baseline within 24 hours, but plasma concentrations of cortisol remain increased for at least 7 days after major surgery. In minimally invasive surgical procedures, when compared with open surgical techniques, the cortisol ‘peak’ is delayed (9).

Figure 2: The surgical stress-response (Figure adapted as original from Cusack et al. (9)