Effect of Dexmedetomidine on Brain Homeostasis and Neurocognitive Outcome

Brain tumor surgery is commonly associated with different degrees of preoperative intracranial hypertension and surrounding tumor edema, elicited by tumor underlying pathophysiology. During craniotomy for brain tumor resection maintenance of hemodynamic stability and intracranial homoeostasis is of paramount importance. Disordered hemodynamics or adverse stress may activate the immune inflammation or neuroendocrine responses and lead to a surge of inflammatory mediators and stress hormones, which are implicated in secondary brain insults. Adverse physiological responses caused by intraoperative disordered hemodynamics or surgery-related damage, may lead to some secondary brain injury (such as cerebral edema or cerebral hemorrhage), aggravating damage to brain tissue and affecting the recovery from anesthesia, cognition and prognosis in patients. Prevention of secondary brain injury is a key-endpoint to improve clinical outcomes in glioma patients undergoing craniotomy. Alpha2-adrenoceptor agonists have been widely used for sedation, analgesia and anti-sympathetic actions for many years, but the definite evidence of their potential use as neuroprotectants has so far been confined to animal studies, yet the findings are inconsistent. Dexmedetomidine (DEX) has been demonstrated to be a new type a2 adrenergic receptor (a2-AR) agonist, which can selectively bind with the a1 and a2 adrenergic receptor, and playing a dual role by restraining the activity of sympathetic nervous and stimulating the vagus nerve. Dexmedetomidine (DEX) also plays an important role in in inhibiting inflammatory and neuroendocrine responses. Animal experiments showed that the right must have a dexmedetomidine neuro-protective effect. However, the brain-protective effect of dexmedetomidine in anesthesia of craniotomy resection of glioma has not been reported. Thus, the aim of this study was to explore the effect of dexmedetomidine on perioperative brain protection, as well as cerebral oxygenation and metabolic status aiming to provide a basis for clinical rational drug use in patients undergoing craniotomy resection of glioma.

Sex

All

Minimum age

18 Years

Maximum age

80 Years

Inclusion Criteria:

* ASA-PS 1-3 (American Society of Anesthesiologists Physical Status classification)
* Scheduled for elective or semi-elective craniotomy for brain tumor resection
* Signed informed consent

Exclusion Criteria:

* History of craniotomy at the same site
* Morbid obesity
* Delirious person before surgery
* Preoperative heart rate (HR) \<45 beats/min or second or third degree AV block
* Treatment with a-methyldopa, clonidine or other a2-adrenergic agonist
* Pregnancy
* Liver or renal failure