Does sympathetic blockade prevent the physiologic changes associated with tourniquet use in children?

This study investigated a means of controlling the altered physiologic effects that occur when tourniquet inflation time is > or = 50 min during orthopaedic surgery in children. Forty patients were assigned randomly, 20 in each group. Both groups received inhalational anesthesia for induction. The control group had nitrous/narcotic with inhalation anesthesia for maintenance. The other group received a sympathetic blockade with 0.5% epidural bupivacaine, which was confirmed with the use of thermography technique and supplemented with 0.5-1% isoflurane. Duration of surgery and length of tourniquet inflation time were equal in the two groups. There was a significant difference in physiologic changes related to the tourniquet inflation time. The group with sympathetic blockade had only minor changes in blood pressure, pulse rate, and temperature compared with the control group.