Introduction

Laparoscopic surgeries in general are associated with increased hemodynamic responses and the anesthesiologists are required to either increase anesthetic depths to supranormal levels or take help of vasodilator drugs or anesthetic adjuvants. Both α2 antagonists and ß blockers have been used in previous studies for the same purpose.^1,2,3. Dexmedetomidine is a α2 antagonist⁴ and esmolol is ultra short acting ß blocker. Use of both of these drugs has never been described for laparoscopic urological surgeries. We will compare the role of continuous infusion of above both drugs and their adverse effects in laparoscopic urological surgeries.

METHODS:

After informed written consent we are planning to study patients undergoing laparoscopic urological surgeries. All the patients will receive balanced general anesthesia with endotracheal intubation and mechanical ventilation in similar pattern as per protocol. They will be divided randomly into two groups.

Group D: receiving Dexmedetomidine 1ug/kg loading dose over 15 minutes then an infusion of@ 0.5ug/kg/hr.

Group E : receiving esmolol loading dose 1 mg/kg over 15 minutes then @15 ug/kg/hr.

 Isoflurane will be titrated to keep pulse and blood pressure within 25% of baseline, by keeping Bispectral Index(BIS) <60 at all times. Injection atropine 0.03 mg bolus will be given for bradycardia and injection mephentermine 6mg bolus for hypotension greater than 25% of baseline and not improving with decreasing isoflurane and fluid boluses. At the end of surgery patient will be extubated and shifted to post op recovery room.

MEASUREMENTS: Pulse and Blood pressure of patient will be taken at baseline, at intubation , on starting drug, at CO2 insufflations, then every 15 mins, at stopping drug, at extubation and in post operative. Duration of surgery, total fentanyl used, time to awakening and time of extubation, sedation scores, pain scores, post operative analgesic requirement, nausea and requirement of antiemetic in post operative will be studied.

Sample size calculation:  There are three parameters of primary objective viz; heart rate, blood pressure and post operative requirement of fentanyl in the recovery room. The variable total fentanyl used is used for sample size calculation. Considering the significance level α = 0.05 and power of the test as 0.9 (90%), a standard deviation of 75 ug in the variable total fentanyl required and critical difference between two drugs taken as 50 ug, the number of cases per group was 45 patients.

  1. Poonam S Ghodhi, Shalini K Thombre, Shalini P Sardesai, Kalpana D Harnagle. Dexmedetomidine as an anesthetic adjuvant in laparoscopic surgery: An observational study using entropy monitoring. J Anaesthesiol Clin Pharmacol. 2012 Jul-Sep; 28(3): 334–338

2.Koivusalo AM, Scheinin M, Tikkanen I, et al. Effects of esmolol on hemodynamic response to CO2 pneumoperitoneum for laparoscopic surgery. Acta Anaesthiol Scand 1998; 42: 510–7

3.Collard V, Mistraletti G, Taqi A, FranciscoJ et al Intraoperative Esmolol Infusion in the Absence of Opioids Spares Postoperative Fentanyl in Patients Undergoing Ambulatory Laparoscopic Cholecystectomy Anesth Analg 2007;105:1255–62.

  4. Bloor BC, Ward DS, Belleville JP, Maze M: Effects of intravenous dexmedetomidine in humans: II. Hemodynamic changes Anesthesiology 1992; 77: 1134–42