Comparison of lower extremity cutaneous temperature changes in patients receiving lumbar sympathetic ganglion blocks versus epidural anesthesia

Study Objective: To investigate if paravertebral lumbar sympathetic ganglion block and lumbar epidural anesthesia result in comparable cutaneous temperature changes in the lower extremity. Design: Nonrandomized comparison study. Setting: Operating rooms and pain clinic procedure rooms in a tertiary care hospital. Patients and Interventions: 18 Patients undergoing lumbar sympathetic ganglion blocks for the diagnosis and/or treatment of chronic pain, and 13 patients undergoing lumbar epidural anesthesia for radical prostatectomy. Measurements: Cutaneous temperatures were measured over the great toe, calf, and thigh in all patients. Mean maximum temperature (Tmax), rate of change of skin temperature (from 5% to 95% of maximum temperature change), and mean time to 1°C increase, and 50% and 95% of maximum temperature change for each group were compared. Temperature changes for the epidural and lumbar sympathetic block patients were compared. Main Results: Epidural and lumbar sympathetic block resulted in similar Tmax (34.1 ± 0.2 and 33.8 ± 0.9°C, respectively, mean ± SEM; p = 0.18) and rate of temperature change (0.64 ± 0.09 and 0.49 ± 0.07°C/min; p = 0.2) in the great toe. The onset of cutaneous temperature change after lumbar sympathetic block was slower than after epidural anesthesia (1°C increase: 17 and 11 min, respectively, 50% of Tmax: 25 and 17 min, respectively, and 95% of Tmax: 40 and 31 min, respectively; p < 0.05 for each). Conclusions: The similar rate and magnitude of cutaneous temperature change in the distal lower extremity suggests the degree of sympathetic blockade is similar with lumbar sympathetic blockade and epidural anesthesia. Either technique should provide adequate sympathectomy for treating sympathetically maintained pain once the diagnosis has been confirmed using selective sympathetic blockade.