Related Experiment Video
Updated: May 8, 2026

Electrophysiological Methods to Assess Peripheral Pain Block in an Anesthetized Rat
Published on: November 21, 2025
Addition of dexmedetomidine to ropivacaine improves cervical plexus block
Yu-Nan Lin1, Qiang Li, Rui-Min Yang
1Department of Anesthesiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
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.
Related Concept Videos
Depolarizing Blockers: Mechanism of Action
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
Depolarizing Blockers: Pharmocokinetics
Skeletal Muscle Relaxants: Therapeutic Uses
Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia
One of the advantages of...
Local Anesthetics: Clinical Application as Epidural Anesthesia
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...
Local Anesthetics: Clinical Application as Spinal Anesthesia
