title: Prospective, randomized study to assess the role of dexmedetomidine in patients with supratentorial tumors undergoing craniotomy under general anaesthesia.
abstract: BACKGROUND
  Preliminary data on the perioperative use of dexmedetomidine in patients undergoing craniotomy for brain tumor under general anaesthesia indicate that the intraoperative administration of dexmedetomidine is opioid-sparing, results in less need for antihypertensive medication, and may offer greater hemodynamic stability at incision and emergence. Dexmedetomidine, alpha 2 adrenoceptor agonist used as adjuvant to anaesthetic agents. Relatively recent studies have shown that dexmedetomidine is able to decrease circulating plasma norepinephrine and epinephrine concentration in approximately 50%, decreases brain blood flow by directly acting on post-synaptic alpha 2 receptors, decreases CSF pressure without ischemic suffering and effectively decrease brain metabolism and intracranial pressure and also, able to decrease injury caused by focal ischemia.
  
  
  OBJECTIVE
  This prospective, randomized, double-blind study was designed to assess the perioperative effect of intraoperative infusion of dexmedetomidine in patients with supratentorial tumors undergoing craniotomy under general anaesthesia.
  
  
  METHODS
  Forty patients with CT- scanning proof of supratentorial tumors. The patients were classified equally into 2 groups (twenty patients in each group). Group A:--The dexmedetomidine was given as a bolus dose of 1 microg/kg in 20 minutes before induction of anaesthesia, followed by a maintenance infusion of 0.4 microg/kg/hr. The infusion was discontinued when surgery ended. Group B:--The patients received similar volumes of saline.
  
  
  RESULTS
  The heart rate and mean arterial blood pressure, decreased in patients of group A (dexmedetomidine group) more than group B (placebo group) with significant statistical difference between the two groups (P-value <0.05). No significant statistical difference between the two groups regarding the central venous pressure and arterial partial pressure of Carbon Dioxide (P-value >0.05). The intraoperative end-tidal sevoflurane (%) in patients of group A less than in patients of group B (P-value <0.05).The intracranial pressure decreased in patients of Group A more than group B (P-value <0.05). The Glasgow coma scale (GCS) improved in patients of group A and deteriorated in patients of Group B with significant statistical difference between the two groups (P-value <0.05). The total fentanyl requirements from induction to extubation of patients increased in patients of group B more than in patients of group A (P-value <0.05). The total postoperative patients' requirements for antiemetic drugs within the 2 hours after extubation decreased in patients of group A more than group B (P-value <0.05). The postoperative duration from the end of surgery to extubation decreased significantly in patients of group A more than group B (P-value <0.05). The total urine output during the duration from drug administration to extubation of patients increased in patients of group A more than group B (P-value <0.05).
  
  
  CONCLUSIONS
  Continuous intraoperative infusion of dexmedetomidine during craniotomy for supratentorial tumors under general anaesthesia maintained the haemodynamic stability, reduced sevoflurane and fentanyl requirements, decreased intracranial pressure, and improved significantly the outcomes.
authors.affiliation: Department of anaesthesia and neurosurgical ICU, Faculty of medicine, Cairo University, Egypt. RABIESOLIMAN@HOTMAIL.COM
authors.forename: Rabie Nasr
authors.initials: RN
authors.lastname: Soliman
authors.forename: Amira Refaie
authors.initials: AR
authors.lastname: Hassan
authors.forename: Amr Madih
authors.initials: AM
authors.lastname: Rashwan
authors.forename: Ahmed Mohamed
authors.initials: AM
authors.lastname: Omar
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D002496:Central Venous Pressure / Q000187:drug effects / Q000502:physiology; D003399:Craniotomy / Q000379:methods*; D020927:Dexmedetomidine; D004311:Double-Blind Method; D005260:Female; D015600:Glasgow Coma Scale; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006993:Hypnotics and Sedatives; D007427:Intracranial Pressure / Q000187:drug effects / Q000502:physiology; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy / Q000453:epidemiology; D020250:Postoperative Nausea and Vomiting / Q000188:drug therapy / Q000453:epidemiology; D011229:Preanesthetic Medication; D011446:Prospective Studies; D015173:Supratentorial Neoplasms / Q000601:surgery*
chemical_list: D006993:Hypnotics and Sedatives; D002245:Carbon Dioxide; D020927:Dexmedetomidine