Studies evaluating sedation during diagnostic or prognostic IA facet joint blocks and MBBs
| Study | Design | Patients | Medications | Results | Comments |
| Manchikanti et al 159 | Randomized, double-blind, three-arm parallel group Measured pain relief before the block | 60 patients with neck pain and LBP who were obtaining long-term relief with serial MBBs | From 1–5 mL of saline, midazolam (1 mg/mL) or fentanyl (50 μg/mL) | 10% in the saline group, 20% in the midazolam group and 25% in the fentanyl group obtained ≥50% pain relief. For ≥80% pain relief, these proportions were 10%, 15% and 10%, respectively. | Light sedation used. No combinations of benzodiazepine and opioid were included; >40% had prior surgery. Did not measure the effect of sedation on block results. It is unlikely patients were blinded. |
| Manchikanti et al 158 | Randomized, double-blind, three-arm parallel group Measured pain relief before the block | 360 patients with neck pain and LBP who were obtaining long-term relief with serial MBBs | From 1–5 mL of saline, midazolam (1 mg/mL) or fentanyl (50 μg/mL) | 13%–15% in the saline group, 15%–20% of the midazolam group and 18%–30% of the fentanyl group had a placebo response (≥80% back pain relief) to diagnostic MBBs. A nocebo (worse pain) effect was observed in 5%–8% of the saline group, 8% of the midazolam group and 3%–8% of the fentanyl group. | Light sedation used. No combinations of benzodiazepine and opioid were included. Did not measure the effect of sedation on block results. It is unlikely patients were blinded. Re-analysis of patients from two earlier studies. |
| Manchikanti et al 156 | Randomized, double-blind, three-arm parallel group Measured pain relief before the block | 180 patients with LBP who were obtaining long-term relief with serial MBBs | From 1–5 mL of saline, midazolam (1 mg/mL) or fentanyl (50 μg/mL) | 7% in the saline group, 5% in the midazolam group and 13% in the fentanyl group obtained ≥50% pain relief. For ≥80% pain relief, these proportions were 2%, 5% and 7%, respectively. | Light sedation used. No combinations of benzodiazepine and opioid were included. Did not measure the effect of sedation on block results. It is unlikely patients were blinded. |
| Manchikanti et al 157 | Randomized, double-blind, three-arm parallel group Measured pain relief before the block | 180 patients with neck pain who were obtaining long-term relief with serial MBBs | From 1–5 mL of saline, midazolam (1 mg/mL) or fentanyl (50 μg/mL) | 8% in the saline group, 13% in the midazolam group and 27% in the fentanyl group obtained ≥50% pain relief. For ≥80% pain relief, these proportions were 5%, 8% and 8%, respectively. | Light sedation used. No combinations of benzodiazepine and opioid were included. Did not measure the effect of sedation on block results. It is unlikely patients were blinded. |
| Cohen et al 160 | Randomized crossover study | 73 patients with suspected sacroiliac joint pain or complex regional pain syndrome received sacroiliac joint or sympathetic blocks with or without sedation | Midazolam and fentanyl, titrated to effect | In the primary crossover analysis, procedures done with sedation had a higher probability of a positive diagnostic block using ≥50% (OR 2.2; 95% CI 1.07 to 4.46; p=0.031) or ≥80% (OR 3.0; 95% CI 1.32 to 6.98; p=0.009) pain relief as the cut-off. | Light sedation used. A similar increase in the positive rate of the diagnostic block was noted for the parallel and omnibus (all sedation vs all no sedation) analyses. Sedation decreased procedure-related pain but did not affect satisfaction scores or 1 month outcomes. |
| Dreyfuss et al 162 | Prospective, observational | 102 patients with cervical, thoracic or lumbosacral radiculopathy receiving epidural steroid injections | Midazolam and fentanyl, titrated to effect | In the sedation group, 49% reported >50% immediate relief of axial pain and 41% reported >50% relief of limb pain. In the no-sedation group, the corresponding proportions were 43% and 37%. | Light sedation employed based on patient preference. Epidural steroid injections are not a diagnostic procedure. |
| Kubulus et al 163 | Retrospective, observational | 42 654 receiving neuraxial and peripheral nerve blocks for surgery | Opioids and benzodiazepines | Improved patient satisfaction in sedated patients | Sedation with opioids and benzodiazepines improved patient satisfaction with the procedure. The regional anesthetic blocks were performed in patients with and without preblock pain and were not diagnostic procedures. Patients were not blinded. |
| Cucuzzella et al 152 | Survey study | 500 patients who received an epidural steroid injection or facet block | Diazepam, 2–5 mg intravenous | 17% requested sedation before initial injection, with 28% stating they would request sedation before a second procedure. | Sedated patients reported slightly higher pain ratings. Factors associated with requesting sedation for a second injection included depression, anxiety and greater pain during initial injection. |
| Kim et al 153 | Prospective, observational | 301 patients who underwent an epidural steroid injection or facet block | Oral sedation: diazepam 5–10 mg intravenous sedation: diazepam 5 mg | 58% of patients requested sedation, with 96% of these choosing intravenous administration. | Request for sedation associated with greater anxiety. Among those who did not request sedation, 93% were satisfied with their decision while 1.5% wished they had received sedation; 90% of patients who received sedation stated their anxiety was controlled. |
IA, intra-articular; LBP, low back pain; MBB, medial branch block.