Control of Tourniquet Pain With an Axillary Ring of Subcutaneous Local Anesthetic
Condition: Application Site Discomfort; Medical Device Discomfort
Study type: Interventional
Phase: Phase 4

Summary: 
      Purpose: Even with excellent regional anesthesia of the upper extremity, tourniquet (Tq) pain
      from an upper arm Tq can limit the ability to use regional anesthesia as the primary
      anesthetic for surgical procedures on the upper extremity. The aim of this study is to
      determine whether a subcutaneous ring of local anesthetic on the inner aspect of the upper
      arm just distal to axillary crease will significantly diminish Tq pain. If it does,
      peripheral nerve blocks distal to the Tq (i.e., nerve blocks at the elbow) could be used as
      the primary anesthetic for surgery of the hand and forearm. These distal peripheral nerve
      blocks have fewer complications than brachial plexus blocks performed at higher levels, and,
      postoperatively, the patient has better control of his or her arm when distal nerve blocks
      are used.

      Procedures (methods): This is a prospective, cross-over study to examine the effectiveness of
      an upper arm Subcutaneous ring of local anesthetic alone in relieving Tq pain. This
      Subcutaneous ring of local anesthetic is often referred to as "Intercostobrachial nerve
      block" or "Subcutaneous ring anesthesia (SRA)." Twenty volunteers will be randomized into
      four groups of 5 participants each. During the initial experiment, the first group will be
      given SRA with 10-15 mL of 0.25% Bupivacaine with Epinephrine 1:200,000 on their dominant
      arm, the second group will be given SRA with 10-15 mL of 0.25% Bupivacaine with Epinephrine
      1:200,000 on their non-dominant arm, the third group will be given "sham" SRA with saline on
      their dominant arm, and the fourth group will be given "sham" SRA with saline on their
      non-dominant arm. 15 minutes after SRA, a Tq will be applied to the arm with the subcutaneous
      injection and it will be inflated to 100 mm Hg above the subject's baseline systolic blood
      pressure. We will monitor heart rate, blood pressure (opposite arm) and pain (0 to 10 VAS)
      every 5 minutes. Each Tq will be released when the subject requests deflation or when 1 hour
      of Tq time has elapsed, whichever occurs first. The subject's discomfort level (VAS) just
      prior to deflation will be recorded. Since Tq pressure alone can inhibit nerve function, we
      will monitor motor and sensory function distal to the Tq every 10 minutes during Tq inflation
      and for 30 minutes after Tq deflation. One to two weeks after this initial study, the same 20
      subjects will receive SRA on the same arm and the same parameters will be measured. The 10
      subjects who received 0.25% Bupivacaine the first time will receive Normal Saline, and the 10
      subjects who received Normal Saline the first time will receive 0.25% Bupivacaine. In this
      way, each subject will act as his or her own control.
    


Intervention name(s): Bupivacaine with Epinephrine; Normal Saline
Intervention type(s): Drug; Drug
Intervention description(s): 10-15 mL 0.25% Bupivicaine with epinephrine 1:200,000 subcutaneous axillary ring
Other intervention name(s): Marcaine, Exparel, Sensorcaine; Placebo
Intervention MeSH terms: Epinephrine; Bupivacaine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Tourniquet pain; Subcutaneous axillary local anesthetic; ability to tolerate tourniquet discomfort.