The influence of timing of systemic ketamine administration on postoperative morphine consumption

Preventive Analgesia with Intravenous Paracetamol for Post-cesarean section Pain Control

“…In present study, we compared the efficacy of preventive administration of paracetamol with patients who received placebo. Bilgin Het al (14) suggested that single-dose preventive ketamine, provided better analgesia compared with when ketamine was administrated preoperatively in patients undergoing gynecologic laparotomy. In previous our study we reported also preventive epidural analgesia with bupivacaine and fentanyl associated with the lower pain scores and opioid requirements postoperatively in patients undergoing major gynecologic surgery (15).…”

Postoperative Ketamine Administration Decreases Morphine Consumption in Major Abdominal Surgery: A Prospective, Randomized, Double-Blind, Controlled Study

“…[3][4][5] Ketamine, a competitive NMDA receptor antagonist, prevents experimentally opioid-induced hyperalgesia, and ketamine in combination with morphine decreases both pain and morphine consumption during the postoperative period. [6][7][8][9] However, the optimal dosing and duration of ketamine administration remains to be determined. Low-dose ketamine induces a morphine-sparing effect when this administration is limited to the intraoperative period 10 or extended to the postoperative period, 11,12 but no study has compared the effects of intraoperative IV ketamine administration alone versus intraoperative and postoperative administration.…”

Evidence-Based Anesthesia for Major Gynecologic Surgery

“…In an RCT in patients undergoing hysterectomy, an intraoperative ketamine infusion reduced morphine consumption by 35%, improved pain scores at 8 to 12 hours after surgery, and improved patient satisfaction with analgesia but did not promote faster return of bowel function or faster ambulation or reduce hospital length of stay. 112 Another RCT in a gynecologic surgery patient population 113 found that a preincision bolus followed by an intraoperative infusion or a bolus of ketamine at wound closure was more effective at reducing pain scores and morphine consumption (by 50%) than 1 preincision dose of ketamine. In patients undergoing myomectomies or hysterectomies for fibroids, no difference in pain scores or opioid consumption was found after a preincision bolus and intraoperative and postoperative infusion of ketamine.…”

“…108 The ketamine infusion dosing regimens varied greatly between studies, with initial dosing of 0.3 mg/kg to 0.5 mg/kg and a continuous infusion of 50 mg to 600 mg/kg/h intraoperatively only or up to 24 hours postoperatively. 108,112,113 It is unclear whether ketamine would provide routine benefit to gynecologic surgery patients or its use should be limited to certain patients, such as those with chronic pain conditions who are on long-term opioids.…”