Prospective Randomized Control Study of Dexmedetomidine for Controlled Hypotension in Functional Endoscopic Sinus Surgery (FESS)

Sugantha, R (2012) Prospective Randomized Control Study of Dexmedetomidine for Controlled Hypotension in Functional Endoscopic Sinus Surgery (FESS). Masters thesis, Madras Medical College, Chennai.

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Abstract

INTRODUCTION: Impairment of intra operative visibility due to bleeding is problem during otorhinolaryngologic surgeries especially in endoscopic surgeries like FESS. Bleeding in the surgical field can lead to incomplete surgical procedure which increases further bleeding and increased risk of complications due to non visualization of important structures. During these surgeries a slightest bleeding at the surgical area would look larger due to magnifying effect of the microscope which could upset surgical comfort. Controlled hypotension is one of the anesthetic techniques used to reduce bleeding during endoscopic surgeries. There are varieties of methods and medications used to obtained deliberate hypotension. The ideal hypotensive agent should be non toxic, maintain cerebro vascular auto regulation, no change in cardiac function, have short term effect and be easily titrated. Alpha 2 agonists like clonidine augment hypotensive action and therefore reduce bleeding. Dexmedetomidine another highly selective Alpha 2 agonist acts by central mechanism and reduces bleeding. I have chosen this study to evaluate the effect of dexmedetomidine on the intraoperative isoflurane requirement to maintain mean arterial pressure of 60-70mmHg, quality of surgical field and awakening time in patients undergoing FESS. AIM: To Evaluate the effect of Dexmedetomidine infusion on the requirement of Isoflurane to produce controlled hypotension (mean arterial pressure of 60- 70mmHg), quality of bloodless surgical field, duration of surgery and the awakening time in patients undergoing Functional Endoscopic Sinus Surgery (FESS). MATERIALS AND METHODS: This study was conducted after obtaining approval from ethical committee and patients consent. Study Design: Prospective randomized control study Patient Selection: 50 ASA I Patients age 18-60 years diagnosed having chronic sinusitis scheduled for FESS under general anesthesia were divided into two groups. Exclusion Criteria: 1. Hypertensive patients. 2. H/o Cerebro-vascular accident / Transient ischaemic attack. 3. IHD. 4. Poor respiratory reserve. 5. Significant hepatic or renal disease. 6. Hypersensitivity to study drugs. 7. Patients who are not willing to participate in the study Materials: 1. Perfusor compact-Syringe infusion pump. 2. Inj.Dexmedetomidine 2 ml amp, Normal saline. 3. Disposable 50 ml syringe. 4. Extension tube. 5. Weighing machine. 6. Monitors – ECG, NIBP, SPO2. Methodology: 50 patients with the above criteria were divided into two equal groups. Group D: Received bolus dose of Dexmedetomidine 1 μg /kg over ten min before induction followed by infusion of 0.5 μg /kg/hr. (2ml of dexmedetomidine was diluted with 48ml of NS making a solution of 4 μg /ml). Group C: Received equal amount of Normal Saline. Preoperative investigations reports like Hb%, Blood Urea, Serum Creatinine, Platelets, Clotting time, Bleeding time were recorded. On arriving to the operating room monitors were connected and baseline vital parameters were noted. Two peripheral intravenous line with 18 G IV Cannula one for IV infusion another for study drug were started. Preloading was done with 10 ml/kg of balanced salt soulations. SUMMARY: The prospective randomized control study aimed to evaluate the effect of Dexmedetomidine infusion on the requirement of Isoflurane to maintain a mean arterial pressure of 60-70mmHg, Quality of blood less surgical field, duration of surgery and awakening time in patients undergoing Functional Endoscopic Sinus Surgery(FESS) under general anaesthesia Important conclusions from this study include 1. Group D lowered intra operative blood pressure better than group C. 2. Group D produced lower intraoperative heart rate than group C. 3. Intra operative isoflurane requirement was low in group D compared to group C. 4. Both the group provided better visualization of the surgical field assessed by the surgeon using Fromme Boezzart scale. 5. The duration of surgery was low in Group D. 6. The awakening time after extubation was also low in Group D compared to Group C. 7. There was no difference in postoperative sedation. CONCLUSION: Dexmedetomidine infusion helps in achieving a targeted reduction in MAP, reduced intraoperative Isoflurane requirement, better blood less field, and faster awakening in patients undergoing Functional Endoscopic Sinus surgery.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Dexmedetomidine ; Controlled Hypotension ; Functional Endoscopic Sinus Surgery (FESS) ; Prospective Randomized Control Study.
Subjects: MEDICAL > Anaesthesiology
Depositing User: Subramani R
Date Deposited: 22 Apr 2018 12:10
Last Modified: 22 Apr 2018 12:10
URI: http://repository-tnmgrmu.ac.in/id/eprint/7218

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