الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Recommendations 113 Intraoperative bleeding impairs surgical field conditions and increases the risk of complications. Application of controlled hypotension improves surgical field visibility and decreases the duration of surgery, total blood loss, and rate of postoperative edema and ecchymosis. Many drugs are used to achieve controlled hypotension during FESS as dexmedetomidine and MgSO4. Other agents including vasodilators (sodium nitroprusside and NTG), β- adrenergic antagonists (propranolol and esmolol), and high doses of potent inhaled anesthetics (isoflurane), have been used. Many of them has disadvantages, such as reflex tachycardia, rebound hypertension and tachyphylaxis as with NTG, cyanide toxicity due to sodium nitroprusside and may be myocardial depression due to esmolol. High doses of inhalational anesthetics lead to prolonged recovery and delay of patient’s discharge from the PACU. The similar clinical characteristics of dexmedetomidine, MgSO4 and propofol beside the stable hemodynamic response to anesthesia and significant reduction of HR following the administration of dexmedetomidine led to the design of the current study to recommend a more effective drug with fewer side effects. We aimed to compare the efficacy of dexmedetomidine, MgSO4 and propofol to reduce MAP during FESS and the resultant effects on the quality of the surgical field in terms of bleeding and visibility. Recovery profile and complications were also compared. This prospective randomized double-blind study was carried out in tertiary care hospital (Tanta University Hospital) for 1 year (from May 2021 to April 2022). Sixty patients aged 21-50 years ASA І and ӀӀ of both gender scheduled for elective FESS were enrolled in this study. After stabilization of general anesthesia, patients were divided into three groups: • group І (Dexmedetomidine group): Patients received a loading I.V dose of 0.5mcg/kg dexmedetomidine within 10minutes followed by continuous I.V infusion dose of 0.2-0.4 mcg/kg/hour throughout surgery. • group ӀӀ (Magnesium sulphate group): Patients received a loading I.V dose of 40 mg/kg of MgSO4 within 10 minutes followed by continuous I.V infusion dose of 10- 15mg/kg/hour throughout surgery. • group ӀӀӀ (Propofol group): Patients received propofol I.V infusion dose of 2-4 mg/kg/hour throughout surgery. Surgery was done by the same surgeon for all studied cases and surgical procedure started 10 minutes after the loading dose of dexmedetomidine, MgSO4 and 10 minutes after starting propofol infusion. We have recorded demographic data (age, gender, weight), hemodynamics as HR, MAP (target 60-65 mmHg), serum cortisol level, duration of surgery, isoflurane total dose consumption ml/hour, total dose of atracurium, the number of patients received fentanyl, nitroglycerine, atropine, or ephedrine and total dose requirement in each group. Also, time of spontaneous breathing and extubation time were recorded. Surgical field in terms of bleeding and visibility and surgeon satisfaction were also measured. Postoperative sedation was evaluated using RSS and postoperative recovery was assessed by the modified aldrete score. Adverse effects such as bradycardia, hypotension lower than the target level, shivering, nausea, and vomiting were recorded and treated. Data collected and statistically analyzed, and we found that the three drugs achieved target MAP but at variable times, the earliest was dexmedetomidine then propofol then MgSO4. Bleeding and visibility of the surgical field and surgeon satisfaction were better with dexmedetomidine than propofol than MgSO4, so, time of surgery was shorter with dexmedetomidine and propofol than that with MgSO4. Serum cortisol level significantly reduced with dexmedetomidine, but insignificantly changed with propofol and MgSO4. Also, we found that spontaneous breathing and extubation of patients were delayed in MgSO4 group more than dexmedetomidine and propofol. The need for atracurium was lower with MgSO4 than with dexmedetomidine and propofol. Also, dexmedetomidine reduced the anesthetic requirements such as isoflurane and fentanyl. Fentanyl and NTG consumption were more with MgSO4 and propofol while isoflurane consumption was less in propofol group. RSS was higher with dexmedetomidine and propofol than MgSO4 at 2hours postoperative and time needed to reach modified aldrete score 9 was longer with dexmedetomidine and propofol than MgSO4, so, discharge of patients from PACU was earlier in MgSO4 group than dexmedetomidine and propofol groups. Bradycardia and atropine needs were more with dexmedetomidine and propofol. There was no bradycardia or atropine needed with MgSO4. Side effects as nausea, vomiting and shivering were less with dexmedetomidine and propofol than with MgSO4. Conclusion: Dexmedetomidine is better than propofol and MgSO4 for controlled hypotension during endoscopic sinus surgery, providing less surgical field bleeding and better visibility and surgeon satisfaction with stable hemodynamics, slow HR and less side effects. Recommendations: 1-Dexmedetomidine is advised as loading I.V dose of 0.5 mcg/kg within 10 minutes followed by continuous I.V infusion dose of 0.2- 0.4 mcg/kg/hr. It provides controlled hypotension and slow HR and so, clear surgical field and surgeon satisfaction. -It has economic impact as it reduces the consumption of inhalational anesthesia. In addition, it reduces pollution from waste anesthetic gas. -It reduces the stress response during surgery by reducing the cortisol level which provides proper healing of the tissues and reduces the incidence of hyperglycemia in diabetic patients. -It reduces consumption of the total doses of narcotics as it provides an excellent perioperative analgesia, so this limits the side effects of narcotics especially with susceptible patients. -It is advised to combine slow HR and low MAP to reduce intraoperative bleeding and to have clear surgical field. -Propofol with its characteristics is a good agent for controlling hypotension. It gives results almost like dexmedetomidine. 2-Further studies are recommended with a greater number of patients to test the loading I.V dose of 0.5mcg/kg of dexmedetomidine to achieve controlled hypotension and slow HR at safe levels and practically useful implications.