Conditions: Carotid Stenosis
Keywords: cervical plexus regional anesthesia ultrasound carotid surgery
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 40
Healthy volunteers: no

Brief summary:
For ultrasound guided intermediate cervical plexus block this randomized comparison is testing the hypothesis, that an additional perivascular infiltration is associated with increased block quality.

Detailed description:
The innervation of the neck is complex and involves the cervical and the brachial plexus as well as cranial nerves. So is the wall of the carotid arteries innervated by vagal and glossopharyngeal nerve as well as the sympathetic trunk. When carotid surgery was performed under regional anesthesia, so additional infiltration of local anesthetic by the surgeon was common, particularly during preparation of the carotid arteries.

Introduction of ultrasound guidance made it possible to guide the needle directly to the vascular wall. But this procedure is considered very demanding, because of guiding the needle in an anatomical region with artifacts (because of calcification), sudden movements (e.g. because of swallowing) and compromised coagulation (antithrombotic medication). On the other side there are no clinical data proving the benefit of an additional perivascular infiltration with local anesthetic. Therefore, this investigation is testing the hypothesis, that an additional perivascular infiltration is associated with increased block quality.

Arms:
arm 1: Ultrasound guided intermediate cervical plexus block: 20ml ropivacaine 0.75%. Ultrasound guided perivascular/pericarotidal infiltration: 5ml ropivacaine 0.75%. arm 2: Ultrasound guided intermediate cervical plexus block: 20ml ropivacaine 0.75%. Ultrasound guided perivascular/pericarotidal infiltration: 5ml saline 0.9%.

Interventions: intervention 1: intermediate cervical plexus block ropivacaine intervention 2: pericarotidal infiltration (active comparator) ropivacaine intervention 3: jugular infiltration prilocaine intervention 4: pericarotidal infiltration (placebo comparator) saline
Intervention descriptions: intervention 1: 20ml ultrasound guided intermediate cervical plexus block. intervention 2: 5ml ropivacaine 0.75% (active comparator): pericarotidal infiltration. intervention 3: 5ml prilocaine 1% jugular infiltration for wound drainage. intervention 4: 5ml saline 0.9% (placebo comparator): pericarotidal infiltration.

Protocol document: