Influence of the Concentration of the Local Anesthetic Ropivacaine on the Quality of a Ultrasound Guided Intermediate Cervical Block.

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.

Study Overview

• Status: Completed
• Conditions: Intermediate Cervical Plexus Block for Carotid Endarterectomy
• Intervention / Treatment: Drug: ropivacaine 0,375%; Drug: ropivacaine 0,75%

• Study Type: Interventional
• Enrollment (Actual): 46
• Phase: Phase 4

Contacts and Locations

Study Locations

• Austria
  • Salzburg, Austria, 5020
    • Klinik für Anästhesiologie, perioperative Medizin und allgemeine Intensivmedizin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patients scheduled for carotid endarterectomy in regional anesthesia

Exclusion Criteria:

• refusal to participate in the trail
• age < 18a
• gestation/breastfeeding
• contraindication for regional anesthesia
• inclusion in other trails

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ropivacaine 0,375%; In the study group the intermediate cervical block will be performed by ultrasound guidance using 20ml ropivacaine 0,375%. Additionally 10ml prilocaine 1% will be used to infiltrate the perivascular tissue around the carotid artery. In the area of the expected incision the skin will also be infiltrated with 10ml prilocaine 1%.	Drug: ropivacaine 0,375%
Active Comparator: ropivacaine 0,75%; In the control group the intermediate cervical block will be performed by ultrasound guidance using 20ml ropivacaine 0,75%. Additionally 10ml prilocaine 1% will be used to infiltrate the perivascular tissue around the carotid artery. In the area of the expected incision the skin will also be infiltrated with 10ml prilocaine 1%.	Drug: ropivacaine 0,75%

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
amount of additional needed local anesthetics by the surgeon	The surgeon will titrate the local anesthetic lidocaine 2%to achieve adequate operative analgesia for the patient. During the surgical procedure the patient will not be sedated therefore distinct communication to the patient is always possible.	The primary endpoint will be evaluated continuously during the ongoing surgery by interrogating the patients pain scale every two to five minutes. In average the whole procedure will take 30 to 50 minutes.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
plasma concentrations of ropivacaine	measured with mass spectrometry	until 8h postoperative
vital signs	continuous recording of vital signs during the surgery as well as in the postoperative ICU	whole day of surgery
effect on the diaphragm function	assessment of phrenic nerve paresis by ultrasound measurement of the diaphragm excursions, performed by the radiologist on call	until 6 h postoperative

Collaborators and Investigators

• Sponsor: Salzburger Landeskliniken
• Investigators: Principal Investigator: Andreas Kokoefer, MD, Salk Institute for Biological Studies

Publications and helpful links

General Publications

• Kokofer A, Nawratil J, Felder TK, Stundner O, Mader N, Gerner P. Ropivacaine 0.375% vs. 0.75% with prilocaine for intermediate cervical plexus block for carotid endarterectomy: A randomised trial. Eur J Anaesthesiol. 2015 Nov;32(11):781-9. doi: 10.1097/EJA.0000000000000243.

Study record dates

Study Major Dates

• Study Start: November 1, 2012
• Primary Completion (Actual): September 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: December 31, 2012
• First Submitted That Met QC Criteria: December 31, 2012
• First Posted (Estimate): January 3, 2013

Study Record Updates

• Last Update Posted (Estimate): March 18, 2014
• Last Update Submitted That Met QC Criteria: March 15, 2014
• Last Verified: March 1, 2014

More Information

Terms related to this study

• Keywords: carotid; endarterectomy; cervical block
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Ropivacaine
• Other Study ID Numbers: cervicalblock; 2012-002769-37 (EudraCT Number)