Amarnath, M (2007) Comparative Evaluation of Oral Atenolol Vs Oral Clonidine as Premedicants for Hypotensive Anesthesia for Patients Undergoing Functional Endoscopic Sinus Surgery under General Anesthesia. Masters thesis, Madras Medical College, Chennai.
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Abstract
INTRODUCTION: Anaesthesia for Functional endoscopic sinus surgery is a challenging job. The surgeons’ operating field itself is very small and surrounded with mucus membranes. It is imperative for the surgeons to look at a clear surgical field in order to identify the diseased tissue properly. A small amount of blood within the field is enough to occlude the view through the endoscope making things difficult for the surgeon, and incomplete removal of the diseased tissue will cause the disease to reoccur. Anaesthesiologists have devised various techniques to prevent this bleeding, of which induced hypotension has stood the test of time. This surgery per se is not a major one by its standards and surgeons recently have been trying to accomplish FESS as a daycare surgery. A good premedication with an antihypertensive agent can help to minimize the amount of volatile agents and vasodilators used to induce hypotension, thereby ensuring much hemodynamic stability and speedy recovery from anaesthesia. Thus I have chosen to study and compare the effects of clonidine and atenolol as oral premedicants for the same. This study proposes to analyze the anaesthetic challenge of keeping the operating field free of blood through pharmacological therapy. It compares how premedicating with either atenolol or clonidine affects the conduct of the fixed anaesthesia protocol evolved in our institute on patients undergoing FESS procedure under GA, and requiring a hypotensive technique to improve operating conditions. AIM: To evaluate the effect of oral atenolol vs. oral clonidine premedication for induced hypotension during general anesthesia for patients undergoing functional endoscopic sinus surgery based on: 1. Intra-operative hemodynamic stability. 2. Requirement of additional vasodilators. 3. Peri-operative side effects and complications. 4. Post-operative hemodynamic stability. MATERIALS AND METHODS: After getting clearance from the ethics committee, the study was formulated as follows: STUDY DESIGN: Randomized experimental double blind study. Case Definition INCLUSION CRITERIA: 1. Patients belonging to ASA I & II. 2. Patients between ages 16 to 60. 3. Patients undergoing FESS procedure. EXCLUSION CRITERIA: 1. Hypertensive patients. 2. H/o Cerebro-vascular accident / Transient ischaemic attack. 3. Moderate and severe IHD, EF < 40% 4. Poor respiratory reserve. 5. Significant hepatic or renal disease. 6. Contraindication for the use of study drug like bronchospasm, COPD, conduction defects and hypersensitivity. 7. Patients who are not willing to participate in the study. SAMPLING FRAME: Patients undergoing Functional endoscopic sinus surgery at the Upgraded Institute of Otorhinolaryngology, Madras Medical College and Hospital, Chennai, India. PROBABILITY SAMPLING: Randomization using the lottery method. Sixty lots (twenty in each group) were placed to randomize the people who were willing to take part in the study. All the patients stand an equal chance of getting into any group with this method. All the patients were aware of the study and informed consent obtained. Sample Size: Sixty patients, twenty in each of clonidine, atenolol and placebo groups. SUMMARY: This prospective randomized study aimed to analyze the effect of atenolol and clonidine premedication on the peri-operative characteristics of patients undergoing FESS procedure under GA and induced hypotensive anaesthetic technique. The important conclusions from this study include; 1. Clonidine and atenolol premedication produces predictable and superior hemodynamics during peri-operative period, with atenolol being superior to clonidine. 2. Clonidine and atenolol premedication decreases the intra-operative requirement of vasodilators like NTG. 3. Clonidine and atenolol premedication decreases the requirement of inhalational anaesthetics like isoflurane to maintain hemodynamic control. 4. Clonidine premedication produces increased incidences of undesirable alterations in BP, which extended into the early post-op period, but could be easily treated. 5. Clonidine produces better sedation and anxiolysis pre-op and reduces the requirement of post-op analgesia as noted by delayed TAR times. 6. Clonidine reduces the incidence of post-anaesthetic shivering. 7. Atenolol produces lesser perturbations in HR and BP in response to intubation. 8. Atenolol produces very minimal hemodynamically adverse events during the perioperative period. 9. Lack of standardization of vasoconstrictors infiltrated by the surgeon maybe a limiting factor in the study. 10. Clonidine premedication produces poorer PADSS score reflecting inability to meet discharge criteria of daycare surgery. 11. FESS procedures seem to be inappropriate for consideration for daycare surgery with the most common morbidity factors being headache and pain. 12. Balanced anaesthesia technique with meticulous attention to patients needs is the single most important factor in production of controlled hypotension during surgery. CONCLUSION: Clonidine and Atenolol premedication provides superior and predictable perioperative hemodynamic control, reduces the requirement of hypotensive agents and produces acceptable recovery characteristics. The lesser incidence of complications recorded with Atenolol gives it a more favorable profile when compared to Clonidine. Clonidine or Atenolol premedication can form an important and desirable part of hypotensive anaesthesia for surgical procedures like FESS.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Oral Atenolol ; Oral Clonidine ; Premedicants ; Hypotensive Anesthesia ; Patients ; Undergoing Functional Endoscopic Sinus Surgery ; General Anesthesia. |
| Subjects: | MEDICAL > Anaesthesiology |
| Depositing User: | Subramani R |
| Date Deposited: | 21 Apr 2018 06:23 |
| Last Modified: | 21 Apr 2018 06:23 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/7177 |
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