Study was conducted on 60 patients undergoing mastectomy after getting approval from Ethical committee and consent. Patients were randomised to two groups of 30 each. Preoperatively, all patients were instructed regarding how to read the Numerical Rating Scale used for assessing the pain in the postoperative period. Premedication was with oral ranitidine 150 mg and metoclopramide 10 mg on the previous night of surgery and on the morning of surgery.

On arrival to the operation theatre, standard monitors were attached and baseline parameters were recorded. Each patient received iv glycopyrrolate 10 mcg/kg, iv ondansetron 0.1 mg/kg, iv midazolam 0.01mg/kg and iv fentanyl 2 mcg/kg. After pre-oxygenation for three minutes, patients were induced with Inj. Propofol 2mg/kg. Endotracheal intubation with appropriate sized, cuffed endotracheal tube was facilitated with Inj. Succinylcholine 1.5 mg/kg. Anesthesia was maintained with nitrous oxide, oxygen and Isoflurane and Inj. Vecuronium bromide 0.1 mg/kg bolus for muscle relaxation. Additional doses of vecuronium were given as deemed necessary by the attending anesthesiologist.

Group K received an intravenous bolus of ketamine 0.2 mg/kg before skin incision followed by 0.2 mg/kg/hour until the end of the procedureand group L received an intravenous bolus dose of preservative free 2% lignocaine 2 mg/kg before skin incision followed by 2 mg/kg/hour till the end of the procedure. Intra-operatively, patient’s vital signs were recorded periodically and patients having fluctuations in HR and MAP >30% of baseline value were treated accordingly. After the completion of the procedure, all infusions were stopped and the patient reversed with  Neostigmine  and  Glycopyrrolate and extubated. The time for extubation and the time for response to oral commands were recorded.

After the procedure, patients were monitored in the recovery room and in the post-operative ward. Any perioperative complications such as tachycardia, bradycardia, hypertension, hypotension, nausea, vomiting, muscle twitching, seizures, respiratory depression were watched for. Numerical Rating Scale  for pain were assessed serially at 10 minutes, 30 minutes, 1 hour, 4 hours, 12 hours and 24 hours after surgery. Inj. Paracetamol 1 gram iv and inj. Tramadol 50 mg iv were given as the first line and second line rescue analgesics respectively and were administered if NRS ≥ 4. The time for first analgesic request was recorded. The duration of analgesia was taken as the time at which patient complained of pain or the NRS was ≥ 4 on assessment at serial intervals. The total dose of rescue analgesics needed in the first 24 hours were also recorded. Postoperatively, sedation was assessed soon after extubation and after 30 minutes by using modified Ramsay sedation score. Development of chronic postsurgical pain was assessed by telephonic enquiry of all patients after 3 months of surgery.