Intermediate Cervical Plexus Block for Carotid Endarterectomy Clinical Trial
Official title:
Influence of the Concentration of the Local Anesthetic Ropivacaine on the Quality of a Ultrasound Guided Block of the Regio Collis Lateralis for Carotid Endarterectomy: a Prospective, Randomized and Controlled Trail
Carotid endarterectomy is commonly performed under cervical plexus block. This is presumed
to offer advantages over general anesthesia in terms of monitoring neurological function
during cross-clamping of the carotid artery since, in conscious patients, speech,
cerebration, and motor power provide early measures of inadequate cerebral perfusion. Some
studies also claim lower shunting requirements, lower cardiovascular morbidity, and shorter
hospital stay.
Traditionally, the common methods of cervical plexus block are termed 'deep' or
'superficial'. The deep block, as described by Moore or Winnie and colleagues, consists of
identifying the transverse processes of upper cervical vertebrae C2 - C4 and injecting local
anesthetic directly into the deep (prevertebral) cervical space. This may be achieved either
as separate injections or as a single injection. The superficial block incorporates a
variety of procedures. The simplest is a s.c. infiltration of local anesthetic along the
posterior border of sternocleidomastoid muscle by either the surgeon or the anesthetist.
An 'intermediate' block is one where the injecting needle pierces the investing fascia of
the neck, deep to the s.c. layer, but superficial to the deep cervical (prevertebral)
fascia. It is also possible to use a 'combined block', consisting of a deep injection and a
superficial or intermediate injection.
Practitioners may prefer one block to another, but no consensus exists on the efficacy of
one block when compared with another. However, it has been suggested that complications of
the technique are related to the deep injection and not the superficial (or intermediate)
injection. These complications include intrathecal or intravascular injection, respiratory
problems related to phrenic nerve paralysis, or local anaesthetic toxicity.
In this study the Influence of the concentration of the local anesthetic ropivacaine on the
quality of the intermediate cervical plexus block for carotid endarterectomy will be
evaluated. For this purpose two different concentrations of ropivacaine will be compared
(3,75% vs 7,5%). The primary endpoint of the study will be the quantity of the additional
needed local anesthetic to achieve adequate operative analgesia. Furthermore we will record
the frequency of the most common side effects as well as the patient satisfaction with a
standardized questionnaire.
n/a
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment