Evaluation of low back pain: Comparative study between psychophysical methods

Abstract

Objective: The aims of this study were to validate the measurement of low back pain by different psychophysical methods and to compare different methods of pain measurement. Methods: This double-blind, randomized experimental study was realized in Brazil. The sample was 60 patients with low back pain, divided into two groups: group I (methylprednisolone 80mg+8mL of 0.9% saline solution) and group II (methylprednisolone 80mg+5mL of levobupivacaine without epinephrine+3mL of 0.9% saline solution), both using 10-mL syringes. The methods were the serial exploration and psychophysical (magnitude estimation, category estimation, and cross-modality matching). Results: Pain evaluation was carried out before the block and 30 minutes, 6, 12, and 24 hours after it. After 30 minutes of epidural block, the levobupivacaine group presented more significant reaction of reduction pain than the saline group. The magnitude and line-length scales were evaluated every period of time, showing no significant differences, except in 12 and 24 hours after the first block. The exponential function to every evaluation ranged from 0.87 to 1.00. Conclusion: This research tries to bring to health care an original method for measuring low back pain. It is noteworthy that in the future, more research is needed to apply this method in clinical and scientific fields. © 2013 American Academy of Pain Medicine.