Ultrasound Guided Supraclavicular Nerve Block

Phase 3

Completed

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
Group 1	Ropivacaine	combined group: ropivacaine and mepivacaine mixture: 1:1 volume mixture of 1.5% mepivacaine and 0.5% ropivacaine in 2 syringes (labeled 1 and 2) with 15 mL in each (total, 30 mL) injected in immediate sequence;
Group 1	Mepivacaine	combined group: ropivacaine and mepivacaine mixture: 1:1 volume mixture of 1.5% mepivacaine and 0.5% ropivacaine in 2 syringes (labeled 1 and 2) with 15 mL in each (total, 30 mL) injected in immediate sequence;
Group 2	Ropivacaine	sequential group: mepivacaine followed by ropivacaine: syringe 1 containing 15 mL of 1.5% mepivacaine, syringe 2 containing 15 mL of 0.5% ropivacaine (total, 30 mL); syringe 2 was injected with a 90-sec delay after injection of syringe 1.
Group 2	Mepivacaine	sequential group: mepivacaine followed by ropivacaine: syringe 1 containing 15 mL of 1.5% mepivacaine, syringe 2 containing 15 mL of 0.5% ropivacaine (total, 30 mL); syringe 2 was injected with a 90-sec delay after injection of syringe 1.

Primary Outcome Measures

Name	Time	Method
Duration of Analgesia.	During surgery: postoperative day 0	The primary outcomes will be the onset time, onset of surgical block, and duration of analgesia.

Secondary Outcome Measures

Name	Time	Method
Time to Complete Motor Block	during surgery from induction time to end case time
Time to Onset of First Sensory Block	during surgery
Maximum Verbal Response Score (VRS) With Rest	through post operative day 3	The severity of postoperative pain was assessed by an observer blinded to treatment using a 0- to 10-point verbal response score (VRS): 0 = no pain and 10= worst pain
Maximum Verbal Response Score (VRS) With Movement	through post operative day 3	The severity of postoperative pain was assessed by an observer blinded to treatment using a 0- to 10-point verbal response score (VRS): 0 = no pain and 10 = worst
Duration of Analgesia	from surgery date to postoperative day 1	Time from the complete onset of sensory block until first request for an analgesic
Total Opioid Consumption	postoperative day 1 to day 3	In morphine equivalent dose