PubMed1998
OBJECTIVE: To determine the incidence of long term backache after lumbar epidural anesthesia with catheter (EPA) in the non-obstetrical setting. DESIGN: Prospective 1-year follow-up study. PATIENTS: All patients scheduled for elective arthroscopical surgery of the knee performed under EPA (n = 195). INTERVENTIONS: A first questionnaire was sent to each patient three months after the operation. To chose patients reporting persistent backache after three months, a second questionnaire was sent one year after the operation. MEASUREMENTS: Back pain before, within 5 days and at the time of the inquiry, i.e., three months and one year after EPA as well as patient satisfaction with the regional anesthetic. Statistic: contingency tables with Fisher's exact test (for categorical variables) and an unpaired t-Test (for continuous variables), p < 0.01 after adjustment for multiple testing (Bonferroni's method). MAIN RESULTS: Response rate was 67%. Before EPA 23 patients (17.5%) complained of back pain. The short term incidence of back pain (i.e, within 5 days after EPA) was 24 out of 131 patients (18.3%) and not associated with pre-epidural back pain (p = 0.036, n.s.). 15 out of 131 patients (11.5%) reported persistent back pain after three months, 13 of them had complained of back pain before EPA (p < 0.0001). Thus, the incidence of new back pain 3 months after EPA was only 1.5%. 7 of the 15 patients returned the second questionnaire: 6 reported still persistent back pain, and all had complained of back pain before EPA. Age, height, weight, sex, duration of anesthesia and operation were not associated with long term back pain. Despite persistent back pain after three months 10 out of 15 patients would opt again for EPA. CONCLUSION: The incidence of long term backache after EPA in the non-obstetrical setting is 11.5% and almost exclusively associated with pre-existing back pain. Biometrical factors seem to play no role. In patients with pre-existing back pain satisfaction with the anesthetic procedure might be improved by improving informed consent.