Ultrasound Guided Supraclavicular Nerve Block

Ultrasound Guided Supraclavicular Nerve Block: Comparison Between a Mixture of Mepivacaine and Ropivacaine, and Sequential Injection of Mepivacaine Followed by Ropivacaine

This study will test the hypothesis that sequential injection of 1.5% mepivacaine followed 90 seconds later by 0.5% ropivacaine in ultrasound guided supraclavicular block provides a quicker onset and a longer duration of analgesia than an equi-dose mixture of the two local anesthetics.

Patients will be randomized into one of two groups, Group M: Ropivacaine and Mepivacaine - subject will receive two injections before surgery begins. These two injections will consist of the mixture of mepivacaine (15 ml) and ropivacaine (15 ml).

Group S: Mepivacaine followed by Ropivacaine. Subjects will receive two injections before surgery begins. One injection will contain mepivacaine (15 ml) and the other will contain ropivacaine (15 ml).

On the first, second, and third mornings after surgery,subjects will be asked to rate their pain on a scale of 1 to 10. If the subject is discharged from the hospital, a telephone call will be made to the subject's home to collect this information.

Inclusion Criteria:

• Patients undergoing upper extremity procedures suitable for supraclavicular anesthesia, including but not limited to oHand surgery oForearm surgery oElbow surgery
• Age between 18 and 70 years

Exclusion Criteria:

• Contraindications to supraclavicular block

  • Coagulopathy
  • Infection at the needle insertion site
  • Severe chronic obstructive pulmonary disease (COPD)
  • Contralateral pneumothorax or diaphragmatic paralysis

• Pregnancy

• Preexisting neuropathy involving the surgical limb

• Routine opioid use

• Inability to attain adequate ultrasound images in the supraclavicular area