Intra-operative Ketamine Infusions in Opioid-dependent Patients With Chronic Lower Back Pain

Summary

Noxious stimuli occurring intraoperatively and postoperatively generate central sensitization, decreasing pain thresholds and ultimately increasing analgesic requirements. The pathophysiology of central sensitization is thought to involve excitatory amino acid receptors such as N-methyl-d-aspartate (NMDA) (1, 2). Ketamine is a N-methyl-d-aspartate (NMDA) receptor antagonist that has been shown to be useful in the reduction of acute postoperative pain and analgesic consumption in a variety of surgical interventions (3). Spine surgery provides a unique opportunity to evaluate the preemptive and preventative impact of ketamine on the primary end points of postoperative 24 and 48 hour opioid consumption in patients with chronic pain. The goal of this double blinded, prospective, randomized placebo controlled trial is to quantify the preemptive and preventative analgesic effects of ketamine infusions in this patient population. Such insight may lead to better pain control, improved satisfaction, and ultimately a reduction in side-effects related to postoperative opioid use.

Timeline

Start

2007-02

Primary completion

2009-04

Completion

2009-04

Publications

• Background 1. Wall PD. The prevention of postoperative pain. Pain 1988; 33: 289-90. 2. Katz J. George Washington Crile, anoci-association, and preemptive analgesia. Pain 1993;53: 243-5. 3. McQual HJ. Pre-emptive analgesia. Br J Anaesth 1992;69: 1-3. 4. Moiniche S, Kehlet H, Dahl JB. A qualitative and quantitative systematic review of preemptive analgesia for postoperative pain relief: the role of timing of analgesia. Anesthesiology 2002;96: 725-41. 5. Katz J. Pre-emptive analgesia: evidence, current status and future directions. Eur J Anaesthesiol Suppl 995;10:8-13. 6. Katz J, McCartney CJ. Update on pre-emptive analgesia. Curr Opin Anesthesiol 2002; 15: 435-41. 7. McCartney et al. A qualitative systematic review of the role of N-Methyl-D-Aspartate receptor antagonists in preventative analgesia. Anesth Analg 2004; 98: 1385-1400. 8. Wu CT, Yeh CC, Yu JC, et al. Pre-incisional epidural ketamine, morphine and bupivacaine combined with epidural and general anesthesia provides pre-emptive analgesia for upper abdominal surgery. Acta Anaesthesiol Scand 2000;44: 63-8.

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