Bupivacaine Digital Blocks: How Long is the Pain Relief and Temperature Elevation?

No one knows how long bupivacaine finger blocks last. Many use bupivacaine with and without epinephrine, but no one knows how the epinephrine affects the duration of the block. We also don't know how long the pain part of the block lasts, which is what counts.

The goal of the study is to determine the duration of action of bupivacaine digital nerve blocks (with and without epinephrine) on finger temperature and the sensory modalities of pain, touch, and pressure. 2 ml of bupivacaine 0.5% with and without epinephrine will be injected at the base of each ring finger on the palm surface. At the end of 1 hr, 6 hrs, 12 hrs, 14 hrs and each additional hour, patients will use an insulin lancet to measure pain, the Semmes Weinstein monofilament test to measure light touch and pressure and a body surface thermometer to measure finger temperature. The time for the finger to return to normal sensation and temperature will be measured.

Study Overview

• Status: Completed
• Conditions: Pain
• Intervention / Treatment: Drug: Bupivacaine 0.5%; Drug: Bupivacaine 0.5% + Epinephrine (1:200,000)

Detailed Description

Lidocaine finger blocks have been shown to provide analgesia for nearly 5 hours without epinephrine and approximately 10 hours with epinephrine - essentially doubling its duration.1,2 The analgesic effect of epinephrine on the duration of bupivacaine finger blocks remains unknown.

Bupivacaine finger injection provides a much longer duration of action than lidocaine. Previous studies have shown the duration of action to be as long as 24.9 hours.1 In the senior author's experience, however, patients who get bupivacaine blocks start asking for pain medication as early as 7 hours after the block. Is it possible that the pain blocking effect of bupivacaine has a different duration than the touch and pressure effects? The answer to this question also remains unknown.

The third unknown question about bupivacaine digital blocks is their effect on fingertip temperature. It has been shown that lidocaine wrist blocks increase temperature in finger tips, and this has been postulated to be potentially helpful in frostbite to provide pain relief and hyperemia.3 Previous studies have shown bupivacaine to exhibit vasodilatory properties at clinical concentrations of injection.4-7 Does bupivacaine provide increased warmth to the finger tip? How long does it last?

The goals of this study are three fold: 1.) To determine what effect epinephrine has on the duration of bupivacaine finger block anesthesia. 2.) To assess the duration of action of bupivacaine with and without epinephrine on the digital sensory modalities of pain, touch and pressure, and 3.) To assess the finger tip temperature changes that result from bupivacaine digital blocks with and without epinephrine.

• Study Type: Interventional
• Enrollment (Actual): 44
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • New Brunswick
    • Saint John, New Brunswick, Canada, E2L 4L2
      • Saint John Regional Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Healthy adult volunteer

Exclusion Criteria:

• Under the age of majority
• Unable to give consent
• Pregnancy
• Diabetes
• Allergy to local anesthetic
• Prior finger surgery
• Preexisting digital vascular ischemia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: Triple

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Ring Finger Nerve Block	Drug: Bupivacaine 0.5%; Drug: Bupivacaine 0.5% + Epinephrine (1:200,000)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Time to return of pin-prick (pain) sensation	24 hours

Collaborators and Investigators

• Sponsor: Lalonde, Donald H., M.D.

Study record dates

Study Major Dates

• Study Start: July 1, 2009
• Primary Completion (Actual): July 1, 2010
• Study Completion (Actual): July 1, 2010

Study Registration Dates

• First Submitted: October 1, 2012
• First Submitted That Met QC Criteria: October 2, 2012
• First Posted (Estimate): October 3, 2012

Study Record Updates

• Last Update Posted (Estimate): October 3, 2012
• Last Update Submitted That Met QC Criteria: October 2, 2012
• Last Verified: October 1, 2012

More Information

Terms related to this study

• Keywords: pressure; pain; temperature; Bupivacaine; epinephrine; duration of action; digital nerve block; touch
• Additional Relevant MeSH Terms: Wounds and Injuries; Body Temperature Changes; Heat Stress Disorders; Hyperthermia; Fever; Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Autonomic Agents; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Adrenergic alpha-Agonists; Adrenergic Agonists; Anesthetics, Local; Bronchodilator Agents; Anti-Asthmatic Agents; Respiratory System Agents; Adrenergic beta-Agonists; Sympathomimetics; Vasoconstrictor Agents; Mydriatics; Bupivacaine; Epinephrine
• Other Study ID Numbers: RS#2009-1356