Preemptive Use of Intravenous Acetaminophen, Ketamine or Their Combination in Patients Undergoing Elective Open Abdominal and Urological Surgeries: Effects on Intraoperative and Postoperative Analgesic Requirements

Study Objective: This study was designed to evaluate the effect of preemptive use of intravenous acetaminophen, ketamine or their combination on intraoperative and postoperative analgesic requirements in patients undergoing elective open abdominal and urological surgeries under general anesthesia. Setting: Beni Suef University Hospital, Egypt. Patients and Interventions: 80 ASA I-II patients undergoing elective open abdominal and urological surgeries under general anesthesia were randomly allocated into four equal sized groups: Group I (n=20): Control group, received IV normal saline 20cc as placebo over 15 minutes IV before induction of anesthesia. Group II (n=20): Received 1 gram acetaminophen over 15 minutes IV before induction of anesthesia. Group III (n=20): Received IV 0.5mg/kg ketamine diluted in 20cc normal saline 15 minutes before induction of anesthesia. Group IV (n=20): Received IV 1 gram acetaminophen and 0.5mg/kg ketamine diluted in 20cc normal saline 15 minutes before induction of anesthesia. Measurements and Main Results: Intraoperative. Heart rate and mean arterial blood pressure: Preinduction, after induction of anesthesia every 15 minutes, intraoperative fentanyl requirements (ug). Postoperative time to first request of analgesia (minutes), postoperative pain at rest measured at 1,8,16, and 24h postoperatively using (VAS), systolic, diastolic arterial blood pressure, heart rate at 1,8,16, and 24h and analgesic requirements of tramadol 50mg im were recorded. Intraoperative and postoperative analgesic requirements were statistically significantly lower, and the time to first request of analgesia was statistically significantly longer in group IV than groups I,II and III. Correspondence to: Dr. Doaa A. Rashwan E-mail:doaa_rashwan2007@yahoo.com Postoperative pain at rest (VAS) was statistically significantly lower in group IV than groups I and II. Postoperative heart rate, systolic and diastolic arterial blood pressure showed no clinical significant differences between the studied groups. Conclusion: Preemptive use of intravenous combination of IV acetaminophen 1g and 0.5mg/kg ketamine decreased intraoperative and postoperative analgesic requirements and pain score more than the use of preemptive intravenous acetaminophen or ketamine alone or palcebo in patients undergoing elective open abdominal and urological surgeries under general anesthesia.