Prospective Randomized Comparison of Three Different Doses of Hyperbaric Bupivacaine Combined with Fentanyl in Randomly Selected Elderly Patients Posted for TURP Surgeries

INTRODUCTION: The aim of anaesthesiology as a science is the removal of pain temporarily have been started initially with pain relief for surgeries, extending now to post operative pain relief and relief from chronic pain and cancer pain. Spinal anaesthesia plays an important role in alleviating pain intraoperatively and also in the post operative period also. The entry of Corning‘s needle in 1885 into subarachnoid space paved the way for the greatest leap into spinal anaesthesia. As a neurologist, Corning‘s objective was to relieve chronic pain in his patients, not to produce operative anaesthesia. Cocaine was the drug first used experimentally in dogs. In men the first spinal anaesthesia was conducted by August Bier on 16.08.1898 with cocaine 3cc as 0.5% solution followed by Rudolph Matas in America and Theodore Tuffier in France. TURP and other cystoscopic urologic procedures are usually done under spinal anesthesia because it provides an adequate anaesthesia for the patient and good relaxation of the pelvic floor and perineum for the surgeon. The complication of cystoscopic procedures can be easily recognized because the patient is awake. Change in the mental status in a conscious patient can be detected early. Sympathetic blockade produced by regional anaesthesia will increase the venous capacitance thereby decreasing the effect of fluid absorption. Bladder perforation is recognized earlier. Decreased requirement of analgesics in the immediate postoperative period. The advantages of neuraxial opioids over neuraxial local anaesthetics are that it produces prolonged, intense and selective segmental analgesia without motor blockade and sympathetic dysfunction. Opioids and local anaesthetics administered together have a potent synergistic analgesic effect. Intrathecal opioids enhance analgesia from subtherapeutic dose of local anaesthetic and make it possible to achieve successful spinal anaesthesia using otherwise inadequate doses of local anesthetic. Hence the present study has been under taken to combine ―Fentanyl‖ a potent synthetic opioid and ―Bupivacaine‖ a long acting local anesthetic for intrathecal administration to provide anaesthesia for endoscopic urological procedures in elderly patients. AIM OF THE STUDY: Regional anaesthesia is the most frequently employed anaesthetic technique for TURP and other endoscopic urologic procedures. These patients are mostly elderly with low cardiac reserve. The conventional dose of Bupivacaine (12.5-15mg) may produce haemodynamic instability. The aim of my study is to find out the minimum effective dose of hyperbaric Bupivacaine with Fentanyl for spinal anaesthesia in elderly patients undergoing TURP surgery. MATERIALS AND METHODS: After getting the approval from the institutional ethical committee study was conducted in 75 patients aged above 60 years undergoing TURP surgery. After getting consent and explaining the procedure details the anaesthetic technique was performed. Inclusion Criteria: 1. Elective elderly male surgical patients posted for TURP surgery. 2. ASA physical status 2. 3. Age 60 yrs and older who have given valid informed consent. Exclusion Criteria: 1. Patient refusal, 2. Post spinal surgeries, 3. Coagulation abnormalities, 4. Cardiac or Renal failure, 5. Neurological illness, Mental illness, 6. Deformity of spinal column, 7. Allergy to local anesthetics, 8. Not fitting into inclusion criteria. RESULTS: In this randomized single blinded study conducted in 75 patients, the subjects were allocated in to three groups . Group A - Received Inj. 0.5% Bupivacaine 1.0 cc, Group B - Received Inj. 0.5% Bupivacaine 1.5 cc, Group C - Received Inj.0.5% Bupivacaine 2.0 cc. All the three groups received 25 mcg of Inj Fentanyl. SUMMARY: From this randomised comparison of three different doses of Bupivacaine with Fentanyl it was found that • All three groups were comparable with respect to age, sex, height, weight, comorbid illness and nature of surgery. • Adequate sensory level was achieved in all the three groups. • Difference in the time to achieve sensory level of T 10 was statistically significant among the three groups, • Adequate motor block to the level of putting the patient in lithotomy was achieved in all the three groups. • Hypotension was observed invariably in the group receiving high dose of Bupivacaine whereas it was less evident in groups using lower dose Bradycardia was observed in patients who had high sensory level. • Adequate analgesia was present throughout the procedure in all the three groups. Postoperative analgesia was significantly prolonged in groups receiving higher dose of Bupivacaine. • Motor block was prolonged significantly in groups receiving higher dose of Bupivacaine. • Nausea and vomiting was not found in any of the groups. Pruritus was found in all the groups but was not statistically significant. CONCLUSION: This study is conducted in patients aged above 60 years. Spinal Bupivacaine was used in variable doses with Fentanyl 25mcg to find out the minimum effective dose of Bupivacaine with Fentanyl 25mcg in elderly patients undergoing endoscopic urological procedures. From this study it can be concluded that addition of Fentanyl 25μg to 5 mg of 0.5% Bupivacaine provides reliable and satisfactory surgical anaesthesia with an ideal peak sensory block height, stable haemodynamic status and without any significant adverse effects when compared to the combination of 10 mg Bupivacaine and 25 μg Fentanyl, in elderly patients undergoing endoscopic urologic procedures