1. Depth of cervical plexus block and phrenic nerve blockade: a randomized trial
- Author
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Mathias Opperer, Reinhard Kaufmann, Matthias Meissnitzer, Florian K Enzmann, Christian Dinges, Wolfgang Hitzl, Jürgen Nawratil, and Andreas Koköfer
- Subjects
Anesthesiology and Pain Medicine ,Anesthesia, Conduction ,Cervical Plexus Block ,Humans ,Ropivacaine ,General Medicine ,Anesthetics, Local ,Ultrasonography, Interventional - Abstract
Background and objectivesCervical plexus blocks are commonly used to facilitate carotid endarterectomy (CEA) in the awake patient. These blocks can be divided into superficial, intermediate, and deep blocks by their relation to the fasciae of the neck. We hypothesized that the depth of block would have a significant impact on phrenic nerve blockade and consequently hemi-diaphragmatic motion.MethodsWe enrolled 45 patients in an observer blinded randomized controlled trial, scheduled for elective, awake CEA. Patients received either deep, intermediate, or superficial cervical plexus blocks, using 20 mL of 0.5% ropivacaine mixed with an MRI contrast agent. Before and after placement of the block, transabdominal ultrasound measurements of diaphragmatic movement were performed. Patients underwent MRI of the neck to evaluate spread of the injectate, as well as lung function measurements. The primary outcome was ipsilateral difference of hemi-diaphragmatic motion during forced inspiration between study groups.ResultsPostoperatively, forced inspiration movement of the ipsilateral diaphragm (4.34±1.06, 3.86±1.24, 2.04±1.20 (mean in cm±SD for superficial, intermediate and deep, respectively)) was statistically different between block groups (pConclusionsWe studied the characteristics and side effects of cervical plexus blocks by depth of injection. Diaphragmatic dysfunction was most pronounced in the deep cervical plexus block group.Trial registration numberEudraCT 2017-001300-30.
- Published
- 2022