Comparison of superficial cervical plexus block and combination of superficial cervical plexus and carotid sheath block in carotid endarterectomy

Background: Carotid endarterectomy (CEA) is a common procedure performed under regional anaesthesia providing monitoring of cerebral function in real time. Numerous techniques of regional cervical blocks exist but superficial cervical plexus block (SCB) is one most commonly used. The aim of this study was to compare infiltration anaesthesia using only superficial cervical plexus block with an ultrasound-guided carotid sheath block combined with superficial cervical plexus block for CEA. Comparison of superficial cervical plexus block and combination of superficial cervical plexus and carotid sheath block in carotid endarterectomy. Methods: Patients undergoing elective CEA surgery were randomly assigned into two groups: one received ultrasound- guided carotid sheath block and SCB (n=12) while another group received SCB alone (n=18). Patients did not receive any premedication. All patients were ASA grade II and III and had invasive blood pressure monitoring with parameters noted every 5 minutes. Both groups received mixture of 2 mg/kg 0.5% levobupivacaine and 2 mg/kg 2% lidocaine supplemented with saline to a volume of 50 mL. The onset and duration of sensory block and time to first analgesia were recorded. Analgesia was measured using numeric pain rating scale (NPRS) every 2 hours, up to 12 hours after regional block was performed. Results: Demographic data and surgical characteristics were comparable in both groups. Block onset time and duration of sensory block were not statistically different in both groups. Time to first analgesia was slightly higher in the group of patients receiving ultrasound-guided carotid sheath block with SCB (difference of medians 124 minutes), but the difference was not statistically significant. Postoperative pain in the first 12 hours described as a probability of NPRS≤ 3 was more prominent in patients having received only superficial cervical plexus block (66.6% as opposed to 58, 3%), but log-rank test showed no significant difference. Cpnclusions: Our early research data do not show benefits of addition of ultrasound-guided carotid sheath block in prolonged postoperative analgesia i.e., time to first analgesia.However, a larger sample size is needed for better statistical power to confirm whether the use of ultrasound-guided technique could prove more beneficial in prolonging postoperative analgesia and sensory block duration time.