Continuous Epidural Infusion of Local Anesthetics and Shorter Duration of Acute Zoster-Associated Pain

OBJECTIVE: The purpose of this study was to investigate the effects of continuous epidural blockade on acute zoster-associated pain, compared with intermittent epidural blocks. DESIGN: The design was a retrospective, nonrandomized study. SETTING: The study was conducted at a university hospital in Japan from 1982 through 1992. PATIENTS: A total of 178 otherwise healthy patients hospitalized with moderate or severe herpes zoster lesions. INTERVENTIONS: Group A (n = 66) had intermittent epidural blocks using 1% mepivacaine, 4-6 ml, three to six time daily; group B (n = 43) were given intermittent epidural blocks and parenteral acyclovir (500 mg/day) or vidarabine (600 mg/day) for 5 days; group C (n = 69) were administered a continuous epidural 0.5% bupivacaine infusion (0.3-1.0 ml/h) for approximately 2 weeks and antiviral agents followed by intermittent blocks. MAIN OUTCOME MEASURES: The number of treatment days was used as the outcome measure. RESULTS: The length of treatment was significantly shorter in group C than in groups A or B. For moderate lesions the means (days) were 36.2 [95% confidence interval (CI), 31.4-41.7), 45.6 (95% CI, 34.0-61.4), and 26.8 (95% CI, 22.3-32.3) for groups A, B, and C, respectively (p < 0.01). For severe lesions they were 73.3 (95% CI, 55.1-97.7), 81.7 (95% CI, 59.1-113.0), and 44.9 (95% CI, 35.2-57.3) for groups A, B, and C, respectively (p < 0.01). CONCLUSIONS: Continuous epidural blockade for patients with acute zoster can shorten the duration of treatment and may reduce the incidence of postherpetic neuralgia.