Dexmedetomidine as an adjuvant in ultrasound-guided supraclavicular block for upper limb orthopedic surgery

Abstract

The administration of local anesthetics in the perineural space is a useful alternative for pain management, but they provide a relatively short duration of effect if not associated with a continuous infusion catheter. Therefore, seeking to improve the quality and prolong the duration of anesthesia and postoperative analgesia in single-dose peripheral blocks, multiple adjuvants to local anesthetics have been studied. One of the used is dexmedetomidine as an adjuvant that we studied in this work. Objectives: a) To evaluate the efficacy and safety of dexmedetomidine as an adjuvant in peripheral blocks. b) To determine latency, duration, motor block and opioid rescue requirements in the postoperative period.

Prospective randomized clinical study in 40 patients undergoing upper limb orthopedic surgery. Ultrasound-guided supraclavicular block was performed, both sexes, 18 to 55 years, ASA I and II. The sample was divided into 2 groups: A (control) received 0.5% ropivacaine and B 0.5% ropivacaine + dexmedetomidine. Level of analgesia, sensory and motor blockade, vital signs and level of consciousness were monitored at different time intervals to assess duration of analgesia and motor blockade, and possible adverse effects. Approved by the corresponding CIEIS.

Analyzing sensory blockade, a clear tendency to decrease the latency period of group B was observed, although the difference was not statistically significant. The same occurred for the time of onset of motor blockade. Regarding intraoperative analgesia and at 6 hours there were no significant differences between the two groups. At 12 hours, a higher percentage of patients with moderate/severe pain was seen in Group A, as well as a greater need for analgesic rescues. Regarding hemodynamic and adverse effects there were no significant differences.

In conclusion, the use of dexmedetomidine as an adjuvant prolongs the analgesic effect, reduces the need for rescue opioids in the postoperative period and prolongs motor blockade, with minimal adverse effects.