LOCAL ANESTHETIC INJECTIONS WITH OR WITHOUT STEROID FOR CHRONIC NON-CANCER PAIN: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

Abstract

The primary focus of this thesis is to establish the clinical utility of corticosteroid injections mixed with local anesthetics, when compared to only local anesthetics, for relief of pain in patients with chronic non-cancer pain. Chronic non-cancer pain is common and causes significant pain and suffering to patients, and economic burden to health care system. Injection of steroids is an option, either by targeting the painful structure or the associated neural elements. Steroids are commonly mixed with local anesthetics in the hope of prolonging the pain relief. Since there is no evident inflammation in most chronic pain conditions, and because existing clinical studies do not consistently support its effectiveness in various clinical conditions, the potential value of adding steroids is questionable. This clinical question has been addressed through a comprehensive systematic review and meta-analysis of randomized control trials comparing injections of steroid with local anesthetics against only local anesthetics for chronic non-cancer pain conditions. Our review found that there is paucity of good quality randomized controlled studies specifically addressing this comparison. Although a large numbers of studies were identified, there was a small effect favoring steroids in studies measuring pain relief by dichotomous outcomes. Overall confidence in the effect estimates were limited due to serious concerns of bias, significant heterogeneity and variability in studies, leading to low quality. A majority of the included studies did not aim to capture the full spectrum of adverse effects. Future studies addressing this clinical question should aim to be of optimum size, must aim to limit the threat of bias, and capture all patient important outcomes including pain relief.