Pregabalin for the Treatment of Pain After Posterior Spinal Fusions

Overview

Acute pain management is challenging in patients after spinal fusions, particularly since most have taken analgesics for prolonged periods before choosing the surgical alternative. Many of these patients are either preoperatively or become after surgery narcotic dependent. In addition, the narcotic based anesthetic required for the procedure, may induce a postoperative hyper-analgesia which may be partially responsible for the acute postoperative pain which is refractory to traditional doses of narcotics. Both the persistent nociceptive and neuropathic pain which these patients experience and narcotic-induced hyper-analgesia is mediated via non-conventional neural pathways. It is for these reasons, that in these patients postoperative pain is refractory to narcotic treatment. Postoperative pain in this situation is best managed using a multimodal approach. This technique allows the application of a number of treatment modalities which maximize pain reduction and minimize treatment side effects. Pregabalin (Lyrica) has been shown to be effective in the treatment of neuropathic pain. Pregabalin has a similar mechanism of action as gabapentin. Notably it has a rapid consistent absorption, linear pharmacokinetics, and a low potential for pharmacokinetic drug interactions. Hence, pregabalin should be a beneficial addition to the multi-modal pain regimen after spinal surgery; particularly in narcotic tolerant patients who respond poorly to conventional narcotic analgesics after surgery.

The treatment of postoperative pain continues to be a challenge, particularly after posterior spinal fusions. Many of these patients have been treated with analgesics or other modalities for prolonged periods before choosing the surgical alternative. In addition, the narcotic-based anesthetic required for the procedure may induce postoperative hyper-analgesia. Inadequate treatment of this pain can result in prolonged hospitalization, cardiopulmonary complications, and poor surgical outcome. However, the narcotic treatment of pain is often associated with multiple adverse effects. Multimodal postoperative analgesia has been instituted to reduce pain while limiting the adverse side effects of opioids. Pregabalin has been shown to be efficacious in the management of chronic pain syndromes with limited adverse side effects. Hence, multiple studies have attempted to demonstrate the benefits of including pregabalin in multimodal postoperative pain management. These studies have yielded conflicting results with regard to reduced pain, opioid consumption, and improved outcome. We propose that the addition of pregabalin to acute pain regimen after posterior spinal fusions should reduce narcotic requirements and hence improve outcome by reducing narcoticinduced side effects. Although recent studies have also examined the administration of pregabalin after spinal fusions, this study was conducted with a uniform anesthetic regimen and similar procedure performed by two spine surgeons at one institution. Pain scores were controlled as well as physical therapy milestones to assess whether changes in the pain regimen would affect narcotic consumption, narcotic induced side effects, and length of hospitalization.