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. STUDY DESIGN: 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. OUTCOME MEASURES: 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.
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ABSTRACT: Epidural steroid injections (ESIs) are the most widely utilized pain management procedure in the world, their use supported by more than 45 placebo-controlled studies and dozens of systematic reviews. Despite the extensive literature on the subject, there continues to be considerable controversy surrounding their safety and efficacy. The results of clinical trials and review articles are heavily influenced by specialty, with those done by interventional pain physicians more likely to yield positive findings. Overall, more than half of controlled studies have demonstrated positive findings, suggesting a modest effect size lasting less than 3 months in well-selected individuals. Transforaminal injections are more likely to yield positive results than interlaminar or caudal injections, and subgroup analyses indicate a slightly greater likelihood for a positive response for lumbar herniated disk, compared with spinal stenosis or axial spinal pain. Other factors that may increase the likelihood of a positive outcome in clinical trials include the use of a nonepidural (eg, intramuscular) control group, higher volumes in the treatment group, and the use of depo-steroid. Serious complications are rare following ESIs, provided proper precautions are taken. Although there are no clinical trials comparing different numbers of injections, guidelines suggest that the number of injections should be tailored to individual response, rather than a set series. Most subgroup analyses of controlled studies show no difference in surgical rates between ESI and control patients; however, randomized studies conducted by spine surgeons, in surgically amenable patients with standardized operative criteria, indicate that in some patients the strategic use of ESI may prevent surgery.Regional anesthesia and pain medicine 05/2013; 38(3):175-200. DOI:10.1097/AAP.0b013e31828ea086 · 2.12 Impact Factor
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ABSTRACT: The Pain Sensitivity Questionnaire (PSQ) is predictive of pain-related responses to experimental stimuli in German-speaking individuals. Here, we explored the validation of the English translation of the PSQ (PSQ-E). One hundred thirty-six patients scheduled to undergo a low back interventional procedure completed the PSQ-E and other questionnaires including the Brief Pain Inventory. Pain ratings on a visual analog scale (VAS) were obtained following 2 standardized injections of subcutaneous lidocaine (VAS 1, infiltration in hand; VAS 2, infiltration of procedural site). The VAS measures were compared with the PSQ-E data and other inventories using linear regression analysis with stepwise selection of variables. The PSQ-E properties were in all respects similar to those of the original German PSQ. VAS 1 magnitude was predicted by PSQ-E-minor (r = 0.26, P < 0.01). VAS 2 magnitude was predicted by PSQ-E-minor (r = 0.34, P < 0.001), and the prediction was significantly enhanced by further inclusion of the Brief Pain Inventory interference score (total r = 0.40, P < 0.001). The study demonstrated that a significant correlation exists between the PSQ-E and clinically relevant pain ratings. This study validates the PSQ-E both in terms of measuring pain sensitivity and as possible means of recognizing patients with high pain sensitivity. Defining this subset of patients may have clinical utility in the future.Regional anesthesia and pain medicine 11/2013; 38(6):508-14. DOI:10.1097/AAP.0000000000000007 · 2.12 Impact Factor