Minimum Effective Volume of Ropivacaine 7.5 mg/ml for the Lateral and Sagittal Infraclavicular Brachial Plexus Block

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Lars Marius Ytrebo, University Hospital of North Norway
ClinicalTrials.gov Identifier:
NCT01493986
First received: December 14, 2011
Last updated: September 9, 2012
Last verified: September 2012

December 14, 2011
September 9, 2012
February 2012
June 2012   (final data collection date for primary outcome measure)
The primary outcome measure is the minimum effective volume of ropivacaine 7.5 mg/ml providing a successful infraclavicular block (LSIB) in 50% of the patients (MEAV50). [ Time Frame: 30 minutes ] [ Designated as safety issue: No ]
Same as current
Complete list of historical versions of study NCT01493986 on ClinicalTrials.gov Archive Site
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Minimum Effective Volume of Ropivacaine 7.5 mg/ml for the Lateral and Sagittal Infraclavicular Brachial Plexus Block
Minimum Effective Volume of Ropivacaine 7.5 mg/ml for the Lateral and Sagittal Infraclavicular Brachial Plexus Block When Using Guidance by Both Ultrasound and Nerve Stimulation.

Systemic LA toxicity is an important complication of regional anesthesia. Lowering the LA dose is one of the strategies to reduce this risk. For upper limb blocks it is well documented that ultrasound guidance allows a significant lower dose of LA for interscalene and axillary blocks than with guidance by peripheral nerve stimulation. However, a corresponding difference has not yet been found for supraclavicular and infraclavicular blocks. The aim of the present study is to define the minimum effective volume of ropivacaine 7.5 mg/ml when using the LSIB method.

The blocks will be performed as previously described, by an anesthesiologist with LSIB expertise. The lateral, medial and posterior cords are the target of infra-clavicular brachial plexus blocks. During a prescan we will record if they can be visualized by ultrasound and indicate their positions periarterially. The deep location of the cords may hamper their identification, especially that of the medial cord. We describe the cord positions with reference to the short-axis (cross-sectional) view of the axillary artery, which is compared to a clockface having 12 o'clock ventrally. In a former MRI study it was found that the cords were usually located in a sector from 3-11 o'clock (the 3-11 sector) and within a distance of 2 cm from the midaxis of the axillary artery. The point closest to the cords was at 8 o'clock, immediately outside the arterial wall. Point of needle insertion is at the intersection between the lower edge of the clavicle and the medial surface of the coracoid process. We direct the needle tip to the 8 o'clock position and observe the spread of LA from this position. On demand we adjust the needle position to secure a complete fill of the 3-11 sector with LA (multiple injections).

The block needle has an electrical cable. Prior to LA injections we test if a minimal electric output (0.2 mA/0.1 msec duration) elicits a motor response. If such a response is obtained, the needle is withdrawn (in steps of 1 mm), until the motor response disappears. This is to reduce the risk of intraneural injection.

Interventional
Phase 4
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Single Group Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Pain
Drug: Ropivacaine
Dosage. Onset time
Other Name: Naropin
Not Provided
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
25
July 2012
June 2012   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • Patients of American Society of Anesthesiologists physical status (ASA) I-II
  • Scheduled for surgery distal to the elbow.
  • Duration of surgery >1 hour.
  • Age 18-65 years,
  • Body mass index 20-35 kg/m2

Exclusion Criteria:

  • Pregnancy
  • Any contraindication to regional anesthesia
  • Patients on major opioids because of chronic pain
  • Atrioventricular block
  • Pacemaker
  • Diabetes
  • Peripheral neuropathy
Both
18 Years to 65 Years
No
Contact information is only displayed when the study is recruiting subjects
Norway
 
NCT01493986
UNorthNorway
No
Lars Marius Ytrebo, University Hospital of North Norway
University Hospital of North Norway
Not Provided
Principal Investigator: Lars M Ytrebo, Professor University Hospital of North Norway
University Hospital of North Norway
September 2012

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP