Clinical Study to Evaluate the Effect of pH on Pain Upon Local Anesthetic Administration.

A Single-center, Randomized, Double-blind Clinical Study to Evaluate the Effect of pH on Pain Upon Local Anesthetic Administration.

When one receives a local anesthetic, such as novocaine for a dental procedure, there is a burning painful sensation experienced upon injection of the local anesthetic. We are trying to understand the role of pH (how acidic a solution is) in the production of pain during local anesthetic administration. We hypothesize that less acidic solutions produce less burning. We also want to determine whether or not the pH of the solution affects the rate of onset of the local anesthesia. We will recruit subjects from patients who have a clinical indication for lumbar medial branch (LMB) nerve blocks, procedures frequently performed at the Massachusetts General Hospital Center for Pain Medicine. For each patient, three nerve blocks are administered at adjacent spinal levels, typically using either lidocaine or bicarbonate-buffered lidocaine as the local anesthetic. We will add a saline control as part of the research procedure and then provide lidocaine at the control location before continuing with the nerve blocks. This clinical procedure offers an ideal opportunity to compare the effects of the three solutions. There will be almost no deviation from the standard clinical procedure. After the injection of each solution, the pain score on administration of the medication will be recorded immediately. We will also provide a continuous stimulation (pin taps) after the local anesthetic injection and record when the patient experiences hypoesthesia (reduced sensation) and anesthesia (absent sensation). Finally, we will record the pain score upon reinsertion of a needle to mark the precise location (part of the clinical procedure) one minute after the local anesthetic injection. All data will be collected during the a single clinical visit.

The study will conclude when 60 subjects have successfully been tested. Data will be reviewed annually.

Study Overview

• Status: Terminated
• Conditions: Local Anesthetics
• Intervention / Treatment: Drug: normal saline; Drug: Lidocaine; Drug: alkalinized lidocaine

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 15 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patients at MGH Center for Pain Medicine who have clinical indication for undergoing diagnostic medial branch block of nerves to facet joints.

Exclusion Criteria:

• contraindication to the clinical procedure
• do not speak English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: lidocaine	Drug: Lidocaine; 1 ml subcutaneous injection of 0.9% lidocaine, given once
Placebo Comparator: normal saline	Drug: normal saline; 1 ml subcutaneous injection 0.9% sodium chloride, given once
Experimental: alkalinized lidocaine	Drug: alkalinized lidocaine; 1 ml subcutaneous injection of 0.9% lidocaine and 0.84% sodium bicarbonate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rank-transformed Pain Score	Pain score upon injection of local anesthetic: the pain score is a validated 11-point numeric rating scale in which patients rate pain between 0 (no pain) and 10 (worst pain imaginable).	immediate, upon injection of each solution

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rank-transformed Time (Seconds) Until Hypoesthesia	Rank-transformed time (seconds) until hypoesthesia will be assessed using a sensory stimulus	0-180 seconds after each injection.
Rank-transformed Time (Seconds) Until Anesthesia	Rank-transformed time (seconds) until anesthesia will be assessed using a repeated sensory stimulus.	0-180 seconds after each injection
Rank-transformed Pain Score Upon Needle Stick.	Pain score upon needle stick: The pain score is a validated 11-point numeric rating scale in which patients rate pain between 0 (no pain) and 10 (worst pain imaginable).	1 minute after each injection

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Investigators: Principal Investigator: Brian J Wainger, MD, PhD, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start: January 1, 2011
• Primary Completion (Actual): November 1, 2014
• Study Completion (Actual): November 1, 2014

Study Registration Dates

• First Submitted: February 18, 2011
• First Submitted That Met QC Criteria: February 23, 2011
• First Posted (Estimate): February 25, 2011

Study Record Updates

• Last Update Posted (Actual): April 11, 2017
• Last Update Submitted That Met QC Criteria: February 28, 2017
• Last Verified: February 1, 2017

More Information

Terms related to this study

• Keywords: pain pH local anesthetics
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Membrane Transport Modulators; Anesthetics, Local; Voltage-Gated Sodium Channel Blockers; Sodium Channel Blockers; Lidocaine
• Other Study ID Numbers: 2010-P-000533