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

• ClinicalTrials.gov Identifier: NCT01304082
• Recruitment Status: Terminated
• First Posted: February 25, 2011
• Results First Posted: April 11, 2017
• Last Update Posted: April 11, 2017
• Sponsor: Massachusetts General Hospital
• Information provided by (Responsible Party): Brian Wainger, Massachusetts General Hospital

Study Description

Brief Summary:

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.

Condition or disease	Intervention/treatment	Phase
Local Anesthetics	Drug: Lidocaine; Drug: normal saline; Drug: alkalinized lidocaine	Not Applicable

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 29 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Double (Participant, Care Provider)
• Primary Purpose: Basic Science
• Official Title: A Single-center, Randomized, Double-blind Clinical Study to Evaluate the Effect of pH on Pain Upon Local Anesthetic Administration.
• Study Start Date: January 2011
• Actual Primary Completion Date: November 2014
• Actual Study Completion Date: November 2014

Arms and Interventions

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

Outcome Measures

Primary Outcome Measures :

1. Rank-transformed Pain Score [ Time Frame: immediate, upon injection of each solution ]

   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).

Secondary Outcome Measures :

1. Rank-transformed Time (Seconds) Until Hypoesthesia [ Time Frame: 0-180 seconds after each injection. ]
   Rank-transformed time (seconds) until hypoesthesia will be assessed using a sensory stimulus
2. Rank-transformed Time (Seconds) Until Anesthesia [ Time Frame: 0-180 seconds after each injection ]
   Rank-transformed time (seconds) until anesthesia will be assessed using a repeated sensory stimulus.
3. Rank-transformed Pain Score Upon Needle Stick. [ Time Frame: 1 minute after each injection ]

   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).

Eligibility Criteria

• Ages Eligible for Study: 19 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

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

Contacts and Locations

Locations

United States, Massachusetts

Massachusetts General Hospital

Boston, Massachusetts, United States, 02114

Sponsors and Collaborators

Massachusetts General Hospital

Investigators

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

More Information

• Responsible Party: Brian Wainger, Instructor, Massachusetts General Hospital
• ClinicalTrials.gov Identifier: NCT01304082
• Other Study ID Numbers: 2010-P-000533
• First Posted: February 25, 2011
• Results First Posted: April 11, 2017
• Last Update Posted: April 11, 2017
• Last Verified: February 2017

Keywords provided by Brian Wainger, Massachusetts General Hospital:

pain pH local anesthetics

Additional relevant MeSH terms:

Lidocaine; Anesthetics, Local; Anesthetics; Central Nervous System Depressants; Physiological Effects of Drugs; Sensory System Agents; Peripheral Nervous System Agents; Anti-Arrhythmia Agents; Voltage-Gated Sodium Channel Blockers; Sodium Channel Blockers; Membrane Transport Modulators; Molecular Mechanisms of Pharmacological Action