Lidocaine and Outpatient Gynecologic Laparoscopy

Overview

Although ambulatory gynecological laparoscopy is considered to be a minimally invasive surgical procedure, only 60% of patients undergoing this procedure are satisfied with postoperative pain control. Postoperative pain can lead to physiological, immunological and psychological derangements in patients.It also has been shown to be the most common cause of hospital admission after outpatient surgery. Opioids constitute the most commonly used pain management strategy after surgery, however they have many undesirable side effects including nausea, vomiting and respiratory depression. Different strategies have been developed to decrease the amount of opioid required after surgery. Opioid sparing drugs as well as regional anesthesia have been shown to be effective. Systemic administration of lidocaine has been shown to decrease opioid consumption, improve recovery of bowel function and promote a better recovery after inpatient procedures. Lidocaine has been shown to have analgesic, antihyperalgesic and anti-inflammatory properties. It also has an excellent safety profile when give by a low-dose infusion. The improvement of surgical technique and anesthesia care has made major adverse outcomes infrequent, especially in the ambulatory setting. Assessing patient's quality of recovery has become an important outcome in several studies. The patient's capacity to return to his normal activities is one of the most important sign of a successful outpatient procedure and it has significant economic implications. Quality of recovery -40(QoR-40) is a validated 40 item instrument to assess the quality of post-operative recovery. Myels et al. have concluded that the QoR-40 would be a useful outcome measure to assess the impact on changes in health care delivery, but anesthesia studies underutilize this instrument. The research question for the study is; does the use of systemic perioperative lidocaine improve quality of recovery after outpatient laparoscopy?

70 subjects will be randomly allocated into 2 groups, using a computer generated table of random numbers. Group A (study group) will receive lidocaine. Group B (control group) will receive the same volume of saline infusion. The study drugs will be prepared by one of the investigators in the study. Subjects will be recruited up to 21 days prior to surgery.They will be premedicated with intravenous (IV) midazolam 0.04 mg/kg. Routine ASA monitors will be applied. Anesthesia will be induced with remifentanil infusion started at 0.1 mcg/kg/minute titrated to keep blood pressure within 20% of the baseline and propofol 1.0 -2.0 mg/kg. Group A will receive lidocaine 1.5mg/kg bolus and Group B the equivalent volume of saline. Subjects will be monitored with a 5 lead EKG throughout the lidocaine administration and if any arrhythmia is detected. The study drug will be stopped and investigators unblinded. Tracheal intubation will be facilitated with rocuronium (0.6 mg/kg) or succinylcholine (1-2mg /kg). Immediately after the induction, group A will receive lidocaine infusion (2 mg/kg/hr IV). Group B will receive the equivalent volume of saline; both infusions will be continued until 1 hour after arrival in the PACU. Anesthesia will be maintained with desflurane titrated to maintain a bispectral index (BIS) between 40-60 , remifentanil infusion started at 0.1mcg/kg/min titrated to keep blood pressure within 20 % of baseline values , and rocuronium that will be administered at the discretion of the anesthesiologist. Upon termination of the surgery, neuromuscular blockade will be antagonized with a combination of neostigmine 0.05mg/kg and glycopyrrolate 0.01 mg/kg. Ondansetron 4 mg IV will be administered to prevent postoperative nausea and vomiting. Subject will be evaluated for pain in the OR after extubation, using a numeric rating scale, if pain greater than 4/10 they will receive hydromorphone (10 mcg/kg IV). In PACU, subjects will receive IV hydromorphone in divided doses as needed to achieve a verbal rating score for pain \<4 out of 10 and they will be evaluated every 15 minutes .They will also receive metoclopramide (20 mg IV ) as rescue antiemetic in PACU. Discharge readiness will be assessed by a PACU nurse using the modified Post Anesthesia Discharge Scoring System (MPADSS) score every 15 minutes for about 3 hours or until ready for discharge.The primary and secondary outcomes will be assessed by an independent observer who will be blinded to group allocation. Study personnel will contact the subject at 24 hours to assess well being, (nausea, vomiting and opioid consumption. Subject will be contacted by telephone by the study staff and will complete the Modified Quality of Recovery 40 (MQOR40) at 24 hours post surgery.