The effects of continuous axillary brachial plexus block with ropivacaine infusion on skin temperature and survival of crushed fingers after microsurgical replantation.

BACKGROUND: Continuous axillary brachial plexus block with local anesthetic has been shown to improve tissue perfusion after replantation surgery of the extremity. The present study aimed to investigate whether continuous axillary brachial plexus block with ropivacaine infusion can improve the survival of the reconstructive fingers secondary to an increase in its skin temperature in patients receiving replantation surgery of the crushed fingers. METHODS: Under general anesthesia, 18 patients received replantation or toe-to-hand transplantation of their crushed digits. They were randomly divided into two groups. Under ultrasound guidance, continuous axillary brachial plexus analgesia was effected by a loading dose of 10 ml 0.75% ropivacaine, followed by an infusion of 4-5 ml per hour for up to three days (Group A). Patients who did not receive continuous analgesia postoperatively served as a control (Group B). An infrared thermometer was used to hourly assess the skin temperature of the surgical and non-surgical sites in both groups for 24 h after the surgery. In addition, the survival (the rate of re-operation or amputation) of the reconstructive digits was also evaluated in both groups. RESULTS: The skin temperature of the digits (T1) on both groups did not show any significant difference at any point of time after the surgery albeit there was a trend of increased skin temperature on the reconstructive digits in patients receiving continuous axillary brachial plexus block (Group A) as compared to those without receiving the block (Group B). Also, the difference in skin temperature (dT) differed slightly at 0, 9 and 21 hours postoperatively in Group A in comparison with Group B (0.75 +/- 0.65 vs. -2.33 +/- 1.24, 0.53 +/- 0.34 vs. -3.02 +/- 1.27, -0.125 +/- 0.55 vs. -2.33 +/- 0.91, p < 0.05). However, no patients in both groups received a second operation or amputation of the graft. CONCLUSIONS: The result of this study demonstrated that axillary brachial plexus block with continuous infusion of 0.75% ropivacaine can increase the skin temperature, an index of tissue perfusion, of the reconstructive digits for 24 h after microvascular surgery of the crushed fingers. However, graft survival was good in both groups.