Effects of adding dexmedetomidine to levobupivacaine in axillary brachial plexus block

Although several studies have described effects of dexmedetomidine on peripheral nerve blocks, to date there is limited knowledge available on the impact of dexmedetomidine adjunct to levobupivacaine in axillary brachial plexus block.

In this study, we aimed to investigate the effects of adding dexmedetomidine to levobupivacaine for an axillary brachial plexus block.

A total of 64 patients of American Society of Anesthesiologists physical status I/II scheduled to undergo forearm and hand surgery, in which an axillary block was used, were enrolled. The patients were randomly divided into 2 groups: in group L patients (n = 32), an axillary block was performed with 39 mL levobupivacaine 5% plus 1 mL of isotonic sodium chloride. In group D patients (n = 32), an axillary block was performed with 39 mL levobupivacaine 5% and 1 mL dexmedetomidine 1 μg/kg(-1) plus isotonic sodium chloride. Demographic data, mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (Spo2), sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, intraoperative verbal analog scale, postoperative visual analog scale (VAS) data, and side effects were recorded for each patient.

There were no significant differences in patient and surgery characteristics between the 2 groups. Sensory block onset time was shorter in group D (P < 0.05). Sensory and motor block duration and time to first analgesic use were significantly longer in group D (P < 0.05), and the total need for analgesics was lower in group D (P < 0.05). Intraoperative 5- and 10-minute verbal analog scale values and postoperative VAS value at 12 hours were significantly lower in group D (P < 0.05). Intraoperative MAP and HR values, except at 5 minutes and postoperatively at 10 and 30 minutes and 1 and 2 hours, were significantly lower in group D (P < 0.01). Bradycardia, hypotension, hypoxemia, nausea, vomiting, and any other side effects were not seen in any patients.

It was concluded in our study that adding dexmedetomidine to axillary brachial plexus block shortens sensory block onset time, increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side effects. ClinicalTrials.gov identifier ISRCTN67622282.