Ultrasound Guided Supraclavicular Nerve Block

• duration of analgesia. [ Time Frame: During surgery ] [ Designated as safety issue: No ]
  The primary outcomes will be the onset time, onset of surgical block, and duration of analgesia.
• Onset time of surgical block [ Time Frame: during surgery ] [ Designated as safety issue: No ]
  The primary outcomes will be the onset time, onset of surgical block, and duration of analgesia.
• Onset time of surgical block [ Time Frame: through post operative day 3 ] [ Designated as safety issue: No ]
  The primary outcomes will be the onset time, onset of surgical block, and duration of analgesia.
• duration of analgesia [ Time Frame: through post operative day 3 ] [ Designated as safety issue: No ]
  The primary outcomes will be the onset time, onset of surgical block, and duration of analgesia.

• time to a significant increase in discomfort [ Time Frame: Post op through day 3 ] [ Designated as safety issue: No ]
  Secondary outcomes will be: time to a significant increase in discomfort, time to a noticeable decrease in numbness and / or weakness, maximum verbal response score (VRS) with rest and movement, and total opioid consumption.
• time to a noticeable decrease in numbness and/or weakness [ Time Frame: through post operative day 3 ] [ Designated as safety issue: No ]
  Secondary outcomes will be: time to a significant increase in discomfort, time to a noticeable decrease in numbness and / or weakness, maximum verbal response score (VRS) with rest and movement, and total opioid consumption
• maximum verbal response score (VRS) with rest [ Time Frame: through post operative day 3 ] [ Designated as safety issue: No ]
  Secondary outcomes will be: time to a significant increase in discomfort, time to a noticeable decrease in numbness and / or weakness, maximum verbal response score (VRS) with rest and movement, and total opioid consumption.
• maximum verbal response score (VRS) with movement [ Time Frame: through post operative day 3 ] [ Designated as safety issue: No ]
  Secondary outcomes will be: time to a significant increase in discomfort, time to a noticeable decrease in numbness and / or weakness, maximum verbal response score (VRS) with rest and movement, and total opioid consumption.
• total opioid consumption [ Time Frame: through post operative day 3 ] [ Designated as safety issue: No ]
  Secondary outcomes will be: time to a significant increase in discomfort, time to a noticeable decrease in numbness and / or weakness, maximum verbal response score (VRS) with rest and movement, and total opioid consumption.

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.

• Drug: Ropivacaine
  mepivacaine (15 ml) and ropivacaine (15 ml).
• Drug: Mepivacaine and ropivacaine
  One syringe will contain mepivacaine (15 ml) and the other will contain ropivacaine (15 ml).

• Active Comparator: Group 1

  One injection with two syringes before surgery begins. These two syringes will consist of the mixture of mepivacaine (15 ml) and ropivacaine (15 ml).

  1:1 volume mixture of 1.5% mepivacaine and 0.5% ropivacaine in two syringes (labeled no. 1 and no. 2) with 15 ml in each (Total: 30 ml).

  Interventions:

  • Drug: Ropivacaine
  • Drug: Mepivacaine and ropivacaine
• Active Comparator: Group 2

  One injection with two syringes before your surgery begins.One syringe will contain mepivacaine (15 ml) and the other will contain ropivacaine (15 ml).

  Syringe no. 1 containing 15 ml of 1.5% mepivacaine. Syringe no. 2 containing 15 ml of 0.5% ropivacaine (Total: 30 ml).

  Intervention: Drug: Mepivacaine and ropivacaine

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