Split Face Study of the Duration of Local Anesthetics

Weill Medical College of Cornell University75 enrolled

Overview

This is a research study to compare how long injectable pain medications (anesthetics) commonly used in dermatologic surgery are effective for. This study will compare a short-acting anesthetic, lidocaine with epinephrine, to one of two long-acting anesthetics (ropivacaine or bupivacaine). This study will also directly compare the duration of actions of ropivacaine and bupivacaine. The investigators hypothesize that the duration of anesthesia of short-acting anesthetics will not differ significantly from long-acting anesthetics at a single site and there will not be a significant difference between the two long-acting anesthetics at a single site.

This study will compare the relative durations of local anesthetics within the same subject at a highly vascularized anatomic region of skin, the nasal ala. This study will test and compare the relative durations and efficacy of commonly used long acting (ropivacaine or bupivacaine) and short acting local anesthetics (lidocaine with epinephrine), delivered via local anesthesia. This study will use a modification of a previously published approach of non-invasive pinprick testing to assess the duration of local anesthetic.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Anesthetics, Local

lidocaine + epinephrine 1:100,000DRUG

0.5 ml lidocaine + epinephrine 1:100,000, buffered 1/10 with sodium bicarb.

Ropivacaine 0.5% Injectable SolutionDRUG

0.5 ml Ropivacaine 0.5% Injectable Solution

Bupivacaine 0.5% Injectable SolutionDRUG

0.5ml bupivacaine 0.5%

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Male or female ≥ 18 years of age * Normal skin sensation at both nasal ala assessed by pinprick * Ability to provide informed consent Exclusion Criteria: * Previous adverse reaction to local anesthetic or any components of the local anesthetics being evaluated * Pregnant or breastfeeding volunteers (assessed by self-report) * Patients taking monoamineoxidase inhibitors (MAOI) or antidepressants of the triptyline or imipramine types

Outcomes

Primary Outcomes

Time to Return to Baseline Sensation, as Determined by Binary Outcomes (Yes/no) in 15 Minute Increments

To determine whether the time to return to baseline sensation differs significantly between each pair of anesthetics, the investigators will measure the time to return to baseline sensation at each anesthetized site by asking participants at 15 minute intervals if they can feel a sharp sensation at the site. Sterile needles will be used. The return of the sensitivity will be determined using binary outcomes (yes/no) and recorded on a standardized template. The maximum difference in anesthetic duration that the investigators consider "not different" from a clinical standpoint is 15 minutes.

Time frame: Up to 4 hours.