A comparison of two techniques of postoperative analgesia: lignocaine-fentanyl intravenous infusion and ropivacaine-fentanyl epidural infusion in patients undergoing major abdominal oncosurgery- a randomized control trial.

Postoperative recovery depends on the quality of perioperative pain relief. Different types of analgesic strategies are used in perioperative period for the patients undergoing major abdominal oncosurgery. Commonly used methods are intravenous (IV) opioid analgesia and epidural analgesia. IV lignocaine infusion in perioperative period is also found to be beneficial for patients for its analgesic, antihyperalgesic and anti inflammatory property. It is very difficult to stamp any strategy as best strategy. There is very limited data available in the literature regarding intravenous infusion of lignocaine and fentanyl simultaneously in the perioperative period. In this study we are planning to compare analgesic efficacy of intravenous lignocaine-fentanyl infusion with epidural ropivacaine-fentanyl infusion.

Patients will be randomized either in the epidural group (Group EPI) or intravenous group (Group IV). All patients will be given GA.In group EPI, epidural catheter will be placed as per incision congruent technique before induction. Placement of the catheter will be checked by 3 ml of 2% lignocaine with adrenaline (1:200000). Epidural analgesia will be activated by 0.15 ml/kg of Ropivacaine 0.2%. After 15 min of epidural drug dose anesthesia will be induced with propofol 2 mg/kg, fentanyl 2 mcg/kg and rocuronium 0.6 mg/kg. After induction patients will be received continuous epidural analgesia with a solution containing ropivacaine 0.2%  and fentanyl 2 mcg/ml at the rate of 0.1 ml/kg/hr. If the patient’s heart rate increases above 20% or SPI above 60 then rescue analgesia will be administered with fentanyl 25 mcg. After the completion of the surgery rate of epidural infusion will be same but the strength of the ropivacaine will be 0.1% instead of 0.2% and fentanyl will be 1 mcg/ml.xml:namespace prefix = "o" ns = "urn:schemas-microsoft-com:office:office" /

In group IV no epidural catheter will be placed. Anaesthesia will be induced with propofol, fentanyl and rocuronium. Just before induction lignocaine bolus dose will be given at a dose of 1.5 mg/kg. Intraoperatively patient will be received lignocaine infusion at 1 mg/kg/hr and fentanyl infusion at 0.5 mcg/kg/hr. If the patient’s heart rate increases above 20% or SPI above 60 then rescue analgesia will be administered with fentanyl 25 mcg. After the completion of the surgery lignocaine infusion will be given at the dose of 0.5mg/kg/hr and fentanyl infusion will be given at the dose of 0.25 mcg/kg/hr.

In both the groups anesthesia will be maintained with desflurane in a mixture of air 40% and O2 60%, and end-tidal concentration of desflurane will be adjusted depending upon the vital parameters. Systolic blood pressure(SBP) will be maintained within 20% of baseline values, and hypotension (SBP<90 mmof Hg) will be treated with IV phenylephrine. If hypotension persist more than 10 mins then analgesic infusion will be reduced by 30%. A thermal blanket will be positioned over the exposed parts of the body to maintain perioperative normothermia. All patients will receive an IV infusion of plasmalyte A at a rate of 8 ml/kg/hour. Thirty minutes before termination of anesthesia intravenous paracetamol at the dose of 15mg/kg will be administered. All the patients will be kept in ICU till 24 hrs in the postoperative period.

In the postoperative period besides their background analgesic infusion through epidural or IV route in group EPI and group IV respectively, all patients will be received fentanyl as rescue analgesia through PCA device. Concentration of fentanyl in PCA device will be 10 mcg/ml, bolus dose will be 20 mcg and lock out time will be 10 min. Patients will receive intravenous fluid with plasmalyte A at the rate of 1.5 ml/kg/hr. If there is hemodynamic compromise [ hypotension (SBP< 90mm of Hg), urine output < 0.5ml/kg/hr] intravenous fluid bolus with 5ml/kg plasmalyte A will be infused and the dose of the continuous analgesia will be reduced by 30% . Same intervention will be repeated if the compromise persists. In both groups multimodal analgesia included intravenous paracetamol 15mg/kg, 4 times a day.

In addition to bradycardia, hypotension, arrhythmia and conduction disturbances, patients will also be monitored postoperatively for the following side effects or symptoms of lignocaine systemic toxicity: circumoral numbness, metallic taste, dizziness, lightheadedness, vision problems, tinnitus, drowsiness, disorientation, twitching, and convulsions.