Systemic effects of epidural steroid injections for spinal stenosis

Abstract

This analysis of the lumbar epidural steroid injections for spinal stenosis multicenter randomized controlled trial data identifies the degree of and risk factors for cortisol suppression after epidural steroid injections in older adults with spinal stenosis. Four hundred patients aged 50 years and older with back or leg pain and central lumbar spinal stenosis completed baseline demographic and psychosocial measures. Morning serum cortisol levels were measured at baseline and 3 weeks after initial injection. Patients were randomized to receive epidural injections of either local anesthetic with corticosteroid (n = 200) or local anesthetic only (n = 200). The specific corticosteroid was chosen at the treating physician's discretion (methylprednisolone, betamethasone, triamcinolone, or dexamethasone). Thirty-two patients (20.3%) treated with corticosteroid experienced cortisol reduction at 3 weeks of >50% compared with 10 patients (6.7%) treated with lidocaine only (adjusted treatment effect = 3.5, 95% confidence interval: 1.6-7.9, P = 0.002). The effect on 3-week cortisol changes did not differ by demographic or patient-level characteristics. Those treated with methylprednisolone or triamcinolone had an average 3-week cortisol reduction of 41.0% (P = 0.005) and 41.6% (P < 0.001) from baseline, respectively, whereas patients treated with betamethasone or dexamethasone were not significantly different than comparable patients in the lidocaine arm. The higher rates of cortisol suppression at 3 weeks in those receiving epidural corticosteroid injections, particularly with longer-acting insoluble corticosteroid formulations, are consistent with sustained systemic absorption of corticosteroid.

Systemic Absorption and Side Effects of Locally Injected Glucocorticoids

“…Recently, a randomized trial of 400 patients aged 50 years and older receiving epidural injections with either local anesthetic only or local anesthetic plus glucocorticoid demonstrated that 20.3% of those given glucocorticoid (dexamethasone, betamethasone, methylprednisolone, or triamcinolone) had >50% cortisol reduction at 3 weeks compared to 6.7% in the lidocaine alone group. 26 In this study, no baseline patient or procedural characteristics were associated with the degree of cortisol suppression with the exception of the type of glucocorticoid administered. Those receiving methylprednisolone or triamcinolone were more affected and had an average cortisol reduction of 41% at 3 weeks.…”

“…The use of concomitant oral, inhaled, intranasal, and even topical glucocorticoids could also potentiate systemic side effects and providers should take an inventory of other forms of glucocorticoids that patients may be using. Studies also suggest that injection of more soluble glucocorticoids may have a shorter duration of systemic effects …”

“…Studies also suggest that injection of more soluble glucocorticoids may have a shorter duration of systemic effects. [26][27][28][29]…”

“…There has been some investigation of HPA axis suppression based on glucocorticoid solubility in ESIs as well. In the large clinical trial on ESIs noted above, Friedly et al demonstrated that after dexamethasone or betamethasone injection, cortisol suppression was comparable to the lidocaine only arm . However, one cohort study of nine patients following a single ESI with 15 mg of dexamethasone describes profound HPA axis suppression at 7 days with normal cortisol levels at 3 weeks .…”

“…In the large clinical trial on ESIs noted above, Friedly et al demonstrated that after dexamethasone or betamethasone injection, cortisol suppression was comparable to the lidocaine only arm. 26 However, one cohort study of nine patients following a single ESI with 15 mg of dexamethasone describes profound HPA axis suppression at 7 days with normal cortisol levels at 3 weeks. 29 Therefore, current evidence suggests that more soluble glucocorticoids have a shorter duration of systemic effect than is associated with less soluble glucocorticoids.…”