Demographic features of low- and high-concentration-anesthetic groups
| Feature | Anesthetic Concentration | |
|---|---|---|
| 0.25% Bupivacaine | 0.5% Bupivacaine | |
| Patientsa (No.) | 175 | 131 |
| Gender, female (No.) (%) | 96 (55%) | 68 (52%) |
| Average age (yr) | 45.7 | 52.8 |
| Average pain duration (yr) | 2.85 | 3.14 |
| LBP only (No.) (%) | 45 (26%) | 43 (33%) |
| LBP+leg pain (No.) (%) | 122 (70%) | 83 (63%) |
| Leg pain only (No.) (%) | 8 (4%) | 5 (4%) |
| Injections (No.) | 237 | 155 |
| Average anesthetic injection volume (cc) | 1.98 | 2.02 |
| VAS: Pre-LESI (average) | 5.84 | 5.63 |
| VAS: Post-LESI (average) | 2.26 | 1.87 |
↵a 30 patients with multiple injections received different anesthetic strength on different LESIs.