Effect of Dexmedetomidine on Plasmatic Cortisol Response in Transsphenoidal Surgery
Effect of Dexmedetomidine on Plasmatic Cortisol Response in Transsphenoidal Surgery
Use of dexmedetomidine in pituitary tumor resection surgery as adjuvant drug and its relation
 to cortisol levels during postoperative period.
Transsphenoidal resection of pituitary tumors is the neurosurgical procedure of choice to
 remove most of the tumors of the sellar region. Sometimes the intervention produces
 dysfunction of the hypothalamic-pituitary axis, and although most are transient, the risk
 associated with post-operative hypocortisolism determines its evaluation early in the
 postoperative period and the possibility of steroidal supplementation posteriorly. It is
 described that dexmedetomidine can be used as an adjuvant drug in this type of surgery being
 useful in reduction of total consumption of opioids and anesthetic gases, maintain
 hemodynamic stability and less time to recovery from anesthesia. Due to its sympatholytic
 effect, dexmedetomidine has been found to alter the intraoperative common neuroendocrine
 response generating lower levels of cortisol in the postoperative period than patients in
 which is not used.

 The main objective of this study is to evaluate corticosteroid axis response (cortisol and
 adrenocorticotropic hormone) in patients undergoing transsphenoidal surgery under anesthesia
 with dexmedetomidine. A single-center randomized double-blind clinical trial will be
 conducted that will compare two groups of patients, one of which will be given
 dexmedetomidine (Dex group) and another group who will receive a placebo (control group). In
 addition the incidence of perioperative complications (nausea, vomiting, diabetes insipidus),
 intraoperative hemodynamics and patient comfort. The investigators expect that the normal
 stress response to surgery measured by cortisol and adrenocorticotropic hormone in the
 postoperative period will be reduced in the dexmedetomidine arm. This effect should be
 transient and attributed to use of dexmedetomidine and not to surgery.
Inclusion Criteria:

 -  American Society of Anesthesiologists physical status I or II.

 -  Pituitary tumour: non-functional macroadenoma, Rathke's cleft cyst, acromegaly.

 -  Normal hypothalamic-pituitary-adrenal axis by hormone levels measurement previous to
 surgery.

 Exclusion Criteria:

 -  Cushing disease.

 -  Pituitary apoplexy.

 -  Craniopharyngioma.

 -  Chronic corticosteroid use.

 -  Hemodynamic instability.

 -  Altered consciousness (Glasgow Coma Scale score less than 15).

 -  Atrioventricular block in any degree.

 -  Preoperative bradycardia.

 -  Alpha 2 agonist use (clonidine, alpha-methyldopa)

 -  Pregnancy or breast feeding.

 -  Known allergy to any of the study drugs.