title: Does pain score in response to a standardized subcutaneous local anesthetic injection predict epidural steroid injection outcomes in patients with lumbosacral radiculopathy? A prospective correlational study.
abstract: OBJECTIVE
  Epidural steroid injections (ESI) are the most commonly performed pain procedures. Despite numerous studies, controversy continues to surround their effectiveness. The purpose of this study is to determine whether a standard, clinical local anesthetic injection can predict outcomes for ESI.
  
  
  METHODS
  In this multicenter study, 103 patients received two ESI 2 weeks apart. Prior to their first injection, subjects rated the pain intensity of a standardized subcutaneous (SQ) injection of lidocaine prior to the full dose. Numerical rating scale pain scores were correlated with leg and back pain relief, and functional improvement, through 3-month follow-up.
  
  
  METHODS
  A composite successful outcome was predetermined to be a ≥2-point decrease in leg pain score, coupled with a positive global perceived effect.
  
  
  RESULTS
  A small but significant relationship was found between SQ pain score and reduction in leg (r = -0.21, 95% CI -0.38 to -0.04; P = 0.03) and back pain (r = -0.22, 95% CI -0.36 to -0.07; P = 0.03). Subjects with a positive outcome at 1 month had a mean SQ pain score of 2.5 (SD 1.9) vs 4.1 (SD 2.7) in those with a negative outcome (P = 0.04). Subjects with SQ pain scores <4/10 had lower leg and back pain scores than those with pain scores ≥4 at 1-month (mean 3.2, SD 2.6 vs 5.1, SD 2.7 for leg, P < 0.01; mean 3.7, SD 2.6 vs 5.0, SD 3.0 for back, P = 0.02) and 3-month (mean 3.8, SD 2.7 vs 5.2, SD 3.1 for leg, P = 0.01; mean 4.0, SD 2.6 vs 4.9, SD 3.1 for back; P = 0.14) follow-up.
  
  
  CONCLUSIONS
  The results of this study found a weak positive correlation between SQ pain scores and treatment results. Further research should consider whether pain perception in conjunction with other variables might prove to be a reliable predictor for ESI and other procedural outcomes.
authors.affiliation: Department of Anesthesiology & Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA. scohen40@jhmi.edu
authors.forename: Steven P
authors.initials: SP
authors.lastname: Cohen
authors.forename: Jianren
authors.initials: J
authors.lastname: Mao
authors.forename: To-Nhu
authors.initials: TN
authors.lastname: Vu
authors.forename: Scott A
authors.initials: SA
authors.lastname: Strassels
authors.forename: Anita
authors.initials: A
authors.lastname: Gupta
authors.forename: Michael A
authors.initials: MA
authors.lastname: Erdek
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Christo
authors.forename: Connie
authors.initials: C
authors.lastname: Kurihara
authors.forename: Scott R
authors.initials: SR
authors.lastname: Griffith
authors.forename: Chester C
authors.initials: CC
authors.lastname: Buckenmaier
authors.forename: Lucy
authors.initials: L
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007268:Injections, Epidural / Q000379:methods; D007279:Injections, Subcutaneous / Q000009:adverse effects; D008012:Lidocaine; D008161:Lumbosacral Region; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D008875:Middle Aged; D010146:Pain / Q000209:etiology*; D010147:Pain Measurement; D017288:Pain Threshold; D010865:Pilot Projects; D011446:Prospective Studies; D011843:Radiculopathy / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D005938:Glucocorticoids; D008012:Lidocaine; D008775:Methylprednisolone