Addition of dexmedetomidine to ropivacaine improves cervical plexus block.

OBJECTIVE

To investigate the sensory block onset time, duration time, and side effects of adding dexmedetomidine to ropivacaine for cervical plexus block.

METHODS

Forty American Society of Anesthesiologists (ASA) Class I or II adult patients who were scheduled to undergo thyroid surgery were randomly allocated to the following groups to receive cervical plexus block: 30 mL of 0.375% ropivacaine combined with 1 μg kg(-1) of dexmedetomidine; 30 mL of 0.375% ropivacaine combined with saline (control). The sensory block onset time, duration of analgesia, mean arterial pressure (MAP), heart rate (HR), and the incidences of side effects, such as hypotension, bradycardia, and hypoxemia were recorded.

RESULTS

The addition of dexmedetomidine to ropivacaine (Group D) shortened the sensory block onset time compared with the ropivacaine group (Group C) (95% confidence interval [CI] 4.18-5.26; p < 0.05). The duration of analgesia of cervical plexus block in Group D was significantly longer than that in Group C (95% CI 295.96-311.12; p < 0.05). The Ramsay sedation score at 5, 10, 20, 40, 60, 90, and 120 minutes after local anesthetic administration in Group D was significantly higher than that in Group C (p < 0.05). MAP level and HR level in Group D were significantly lower than that in Group C (p < 0.05).

CONCLUSION

The addition of 1 μg kg(-1) dexmedetomidine to ropivacaine for cervical plexus block could shorten the sensory block onset time and extend the duration of analgesia, and increased the quality of analgesia, with the patients being sedated and arousable.