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

Condition(s) targeted: Local Anesthetics

Intervention: Lidocaine (Drug); normal saline (Drug); alkalinized lidocaine (Drug)

Phase: N/A

Status: Recruiting

Sponsored by: Massachusetts General Hospital

Official(s) and/or principal investigator(s):
Brian J Wainger, MD, PhD, Principal Investigator, Affiliation: Massachusetts General Hospital

Overall contact:
Brian Wainger, MD, PhD, Phone: 617 726-8810, Email: bwainger@partners.org

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.

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

Study design: Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver), Primary Purpose: Basic Science

Primary outcome: pain score

Secondary outcome:

time until hypoesthesia

time until anesthesia

pain score upon needle stick.

Minimum age: 19 Years. Maximum age: N/A. Gender(s): Both.

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

Brian Wainger, MD, PhD, Phone: 617 726-8810, Email: bwainger@partners.org

Massachusetts General Hospital, Boston, Massachusetts 02114, United States; Recruiting

Starting date: January 2011
Last updated: December 16, 2013