Analgesic Effects of Low Dose Ketamine in Patients Undergoing Spine Fusion Surgery

Postoperative analgesia in spine surgeries is necessary for postoperative recovery and wound healing. While opioids have their limitations, non-opioid analgesia is a growing field of interest. Ketamine, due to its analgesic properties, has emerged as a promising agent for postoperative analgesia. Our aim was to study the analgesic effect of low-dose ketamine infusion and to explore its potential for a multimodal pain management strategy.

This prospective observational cohort study was conducted at Sher-i-Kashmir Institute of Medical Sciences, a tertiary care hospital in Srinagar, India. A total of 44 patients were observed and divided into two cohort groups of 22 each based on their intraoperative analgesic regimen. One group had received a low-dose ketamine infusion (0.3 mg/kg/hour) both intraoperatively and postoperatively, and another group received regular analgesics (fentanyl, morphine, and paracetamol) except for the ketamine infusion. Pain score measured using the Visual Analog Scale (VAS), rescue analgesic requirement, and associated side effects were studied for a period of 48 hours.

Ketamine administration led to a significantly lower VAS pain score at 4, 6, 12, and 18 hours postoperatively (p-value < 0.05). Adjustment for pair comparisons confirmed that the most substantial pain reduction occurred at four and six hours, indicating ketamine's early-onset analgesic effect. Patients belonging to the ketamine group also demonstrated lower cumulative opioid use (mean difference: -16.00; CI: -19.68 to -12.32, P < 0.0001) at 48 hours postoperatively, higher satisfaction with pain management, and shorter hospital stays (mean: 4.45 days vs. 5.77 days), reinforcing ketamine's potential for improving early recovery outcomes.

Ketamine may demonstrate substantial promise as a safe and effective option for perioperative pain management, particularly in the early postoperative phase.