Meenakshi, R (2008) Oral Clonidine as a Hypotensive Agent in Fess Surgery. Masters thesis, Stanley Medical College, Chennai.
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Abstract
INTRODUCTION: The recent past has seen an enormous surge in Endoscopic Surgery of the Paranasal Sinuses. The nasal mucosa is rich in blood supply, hence impaired visibility ensues owing to excessive bleeding, leading to a prolonged surgical time. To avoid such complications, Endoscopic Sinus Surgery can be performed either with local anesthesia, with vasoconstrictors (e.g. Epinephrine, Cocaine and Phenylephrine), or under general anesthesia supplemented with controlled hypotension. Several reports have been recorded regarding various techniques for diminishing intraoperative bleeding. Many ENT surgeons prefer general anesthesia to local anesthesia. They are comfortable with hypotensive anaesthesia since the duration of surgery is reduced considerably with an excellent view of the surgical field. Hypotension maybe induced with drugs and volatile anaesthetics each having its own advantages and drawbacks. For example., severe hypotension may occur due to potent and rapid effects of intravenous antihypertensive drugs. Clonidine is a centrally acting α2 agonist useful as a premedicant. It also decreases the need for analgesic consumption and the usage of multiple hypotensive agents intra-operatively. Post operative nausea, vomiting and shivering is also reduced. It has antihypertensive property with decreasing sympathetic outflow. The use of drugs such as oral clonidine given before surgery would be desirable to enhance the hypotensive action of an inhalation agent without the disadvantages of intravenous vasodilators20,21 and the avoidance of polypharmacy. AIM: To analyse oral clonidine given as a premedicant in patients undergoing FESS Surgery and its effects; 1. As a hypotensive agent. 2. On intra operative bleeding using a bleeding severity score. 3. In maintaining haemodynamic stability intra operatively. 4. Reducing antihypertensive drug requirements. 5. As a premedicant for sedation, intra operative and post operative Analgesia. 6. To evaluate the side effects and complications if any that may arise with the use of clonidine. MATERIALS AND METHODS: Sixty ASA Class I patients of both sexes between the age of 20 – 40 years weighing between 40 – 65kgs, who were scheduled for elective Endoscopic Nasal Sinus Surgery under General Anaesthesia at Government Stanley Hospital were selected for this study. This study was designed as prospective randomized comparative study. After receiving the institutional ethical committee approval and informed consent, the patients were allocated into two groups, the clonidine group (C) and the placebo group (P), each group comprising of thirty patients respectively. Inclusion Criteria: (i) ASA PS I. (ii) Age 20 – 40 years. (iii) Weight between 40-65 kgs. (iv) Patients undergoing FESS surgery. Exclusion Criteria: (i) Hypertension/ Ischaemic Heart Disease (IHD)/ Rheumatic heart disease. (ii) Diabetes Mellitus. (iii) Obesity. (iv) Anticipated difficult airway. (v) Sinus bradycardia / heart blocks / conduction defects. (vi) Patients on Antipsychotics. (vii) Patients on Digitalis, Calcium Channel Blockers and β-blockers. (viii) H/o CerebroVascular Disease (CVA). (ix) Chronic renal disease with increased renal parameters. (x) Preoperative Hypotension. (xi) Patient refusal. All the patients were informed about the procedure and written consent obtained. Prof. of ENT Department was informed about the study and his prior permission was obtained. This study was carried out in the theatre where facilities for Induced Hypotension and Resuscitation were available. STATISTICS AND ANALYSIS: Sample size of 30 per group was taken for this study. Data was expressed as mean ± standard deviation (SD) or absolute values. Qualitative data were compared with the Chi square test and fisher’s exact test. Quantitative variables were compared with the student ‘t’ test. The level of statistical significance was set at p <0.05. SUMMARY: The advantages of Clonidine as premedicant can be summarized as follows: * Excellent Sedation and Anxiolysis. * Attenuation of stress response to laryngoscopy and intubation. * Maintenance of intraoperative cardiovascular stability by maintaining Heart Rate and Blood Pressure. * Good intraoperative analgesia. * Postoperative Sedation and Analgesia. * Devoid of Respiratory depression. * Less distressing side effects like nausea and vomiting. * Easy administration. Clonidine possesses certain limitations in its usage in patients with bradycardia, conduction disturbances and cardiovascular instability as it is likely to worsen the Cardiovascular status. As it may cause excessive sedation, it is better to be avoided or used with caution in patients with airway obstruction, obesity and extremes of age. Clonidine at a dose of 5 μg/kg body weight with a ceiling dose of 300 μg is tolerated well by the patients without major complications. Premedication with oral Clonidine in FESS surgery greatly facilitated controlled hypotension with a clear surgical field which was greatly appreciated by the operating surgeon. CONCLUSION: The present prospective randomized controlled study shows that Oral Clonidine premedication 90 minutes prior to surgery provides a considerable reduction in bleeding during Functional Endoscopic Sinus Surgery under General Anaesthesia (with 0.25V% Halothane supplementation). It also reduces (almost negligible) the need for other hypotensive drugs to provide a clear field for surgery. Therefore Oral Clonidine can be used as premedicant as well as a hypotensive agent for FESS surgery.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Oral Clonidine ; Hypotensive Agent ; Fess Surgery. |
| Subjects: | MEDICAL > Anaesthesiology |
| Depositing User: | Subramani R |
| Date Deposited: | 22 Apr 2018 15:48 |
| Last Modified: | 28 Apr 2018 05:56 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/7237 |
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