The ESI technical quality scale was developed by the investigators after a review of clinical studies evaluating factors associated with treatment outcomes for ESI and back pain in general. Study risk of bias was assessed using a Cochrane risk of bias tool ‖ and secondarily using Jadad 40 methodological quality scale, whereas an ESI technical quality scale evaluated stringency of selection criteria ( table 2). This was done by comparing between-group differences for pain outcomes from RCTs in which the “control” injectate was administered epidurally (ENSI), with those in which it was injected into the soft tissue (nonepidural injection). The purpose of this study is to examine whether epidural injections of noncorticosteroid mixtures constitute a treatment or true placebo in patients with spinal pain. 9, 28, 31, 36, 37 If ENSI provide benefit, then the proportion of controlled studies evaluating ESI in which the results are positive should be less when the control group received ENSI than for nonepidural injections, because the former constitutes a comparative-effectiveness study. However, few investigators have entertained this possibility. 32, 33 Hence, ENSI may provide significant pain relief by several mechanisms: diluting inflammatory cytokines lysing scar tissue enhancing blood flow to ischemic nerve roots 34 suppressing ectopic discharges from injured nerves 35 and “unwinding” central sensitization. In addition, recent studies suggest that radiculopathy may also result from chemical irritation of nerve roots due to inflammatory cytokines released from herniated discs.

In evaluating the literature, most experts fail to discern the differences, considering them as “equivalent placebos.” However, the potential benefit of corticosteroids for a chronic condition devoid of an inflammatory component is minimal.

Two main types of “control” injections are used in ESI randomized controlled trials (RCTs): epidural saline or local anesthetic and intramuscular or ligamentous injections (nonepidural).

931 da paina