Systemic Absorption of Lidocaine After Hematoma Block

December 11, 2023 updated by: Washington University School of Medicine

Systemic Absorption of Lidocaine After Ultrasound Guided Hematoma Block for Reduction of Different Types of Pediatric Distal Radius Fractures

This study will measure in children how much numbing medicine, lidocaine, is absorbed into the bloodstream after it is injected into a blood clot (hematoma) around a forearm fracture for pain control when the broken bone is moved back into place (fracture reduction). This is called a hematoma block and is commonly used in the Emergency Unit. To help with anxiety and to add additional pain control, nitrous oxide (laughing gas) is given while the lidocaine hematoma block is placed and continued during the fracture reduction. Advantages of using this technique for pain control instead of an intravenous anesthetic such as ketamine include faster recovery and discharge home, and longer pain control.

Of concern, if too much lidocaine is absorbed into the bloodstream, seizures and irregular heart beating may occur. Bloodstream concentrations of lidocaine after a hematoma block have been measured in only one study of 8 adults and found to be at significant but safe levels. No study has been published in children to measure bloodstream lidocaine levels when a hematoma block is used. Because children's bones are still growing and more metabolically active than adult bones, the investigators believe it is important to determine whether lidocaine blood levels in children are also at safe levels when using a standard lidocaine hematoma block for reduction of fractures. The investigators also want to determine whether bloodstream lidocaine levels correlate with type of fracture.

The investigators also aim to determine if there is a difference in absorption pattern between different types of distal radius fractures, if there is a correlation between fracture type and systemic lidocaine absorption, and if there is a correlation between fracture type and ability to provide adequate pain and sedation control with lidocaine hematoma block/inhaled nitrous combination. The investigators believe blood lidocaine levels after hematoma block in children will peak at safe levels, but will be higher than those observed in adults.

Study Overview

Status

Withdrawn

Conditions

Intervention / Treatment

Detailed Description

When a subject with an eligible distal forearm fracture is identified, the subject will be approached for enrollment and consent.

50% nitrous oxide/50% oxygen then will be administered to the subject by face mask for a minimum of 2 minutes before venous catheter insertion (50% nitrous oxide will continue to be administered until fracture reduction is completed). Nitrous oxide currently is administered regularly in the St. Louis Children's Emergency Department for painful procedures including fracture reduction, abscess incision and drainage, laceration repair and venous catheter placement. Nitrous oxide 50% blended with 50% oxygen will be administered for this study by credentialed emergency unit staff using a continuous flow delivery system that includes scavenging of exhaled nitrous oxide. Standard monitoring for deep sedation will be used as described in the clinical protocol.

A venous catheter then will be inserted into the uninjured arm. A lidocaine hematoma block will be injected under ultrasound guidance by a pediatric emergency medicine physician using 2.5 mg/kg, maximum of 100mg, of 1% buffered lidocaine. The recommended lidocaine dose for hematoma block in children is 3-5 mg/kg. However, in a previous study, in another pediatric trial, and in the single report of plasma lidocaine levels in adults, 2.5 mg/kg of 1% lidocaine based upon the patient's weight, maximum 100 mg, was found effective and without adverse effects. The Pediatric Sedation State Scale will be administered by the sedation provider, and a research assistant when available, and used to determine if pain control is adequate, or if rescue IV analgesia is needed. This scale has been validated for procedural sedation.

Serial blood samples will be drawn through the indwelling venous catheter by a nurse or medic at 5, 10, 20, 40 and 60 minutes after injection of the hematoma block. Serial plasma lidocaine levels will be measured as follows. 5 mL samples of blood will be obtained via the indwelling venous catheter at 5, 10, 20, 40 and 60 minutes after injection of the lidocaine hematoma block. The samples of blood will be collected in standard red top vacutainer blood tubes and processed, frozen and stored in the SLCH/BJC Lab.

At 5 minutes after the hematoma block injection, the orthopedic surgeon will attempt fracture reduction. If the subject has minimal response to squeezing the fracture site prior to 5 minutes post injection, reduction may begin at that time. Nitrous oxide administration will be stopped and administration of 100% oxygen will begin when the orthopedic surgeon indicates satisfactory fracture reduction as determined by bedside fluoroscopy (standard procedure), a cast or splint has been applied, and, if necessary, the cast has been split. Oxygen administration will be stopped when the subject's exhaled nitrous oxide concentration falls below 10% or the subject pulls the nitrous oxide mask off the face.

If the subject resists the fracture reduction, verbally indicates significant pain, or has an unfavorable PSSS, ketamine sedation will be administered via the indwelling venous catheter and fracture reduction completed under deep sedation. Post procedure pain score via the Wong-Baker Faces scale, and post procedure surveys will be administered 15 minutes after nitrous administration is stopped. After the subject's recovery from sedation, the subject, subject's parents/guardians, physician providing sedation (inhaled nitrous) and the orthopedic surgeon will be asked to rate their satisfaction with the sedation and analgesia for the fracture reduction using a Likert scale ranging from 1 (not satisfied at all) to 10 (very satisfied). Recovery from sedation satisfactory for discharge home is indicated by a score of 10 on the Modified Aldrete Scale below, and the child can sit up unaided along with control of pain and vomiting. Family will be contacted via telephone 48 hours after their visit to assess for any late adverse effects.

Adverse events will be documented on a data collection sheet using consensus-based definitions that include the event, time and any intervention employed. In addition, the subject will be asked about symptoms typically seen with procedural sedation and lidocaine toxicity including: vomiting, nausea, tinnitus, circumoral or tongue numbness, metallic taste in mouth, nystagmus, vision changes, muscle twitching, tremors, seizure, respiratory depression, chest pain, difficulty breathing, palpitations, ECG changes on monitor (type noted, ECG strip printed), and any other unpleasant or euphoric symptom.

Study Type

Interventional

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Missouri
      • Saint Louis, Missouri, United States, 63110
        • Saint Louis Children's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

5 years to 17 years (Child)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • ASA status class 1 or 2
  • Ages 5-17
  • Parent/guardian is present

Exclusion Criteria:

  • Open fracture
  • Previous attempt at reduction
  • Multiple other injuries
  • Physeal (growth plate) fractures
  • Volar displacement of the distal fracture fragment
  • Delayed presentation (>48 hrs from injury)
  • Concern for significant neurovascular injury
  • Refracture through a healing fracture
  • History of adverse effect from lidocaine or nitrous oxide
  • Active psychosis
  • Non English speaking parents
  • Liver disease
  • Cardiac disease
  • Abnormal bones such as osteogenesis imperfecta or osteopenia from lack of use
  • Developmental abnormalities

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lidocaine Hematoma Block
Drug: Lidocaine 1% Injectable Solution
The lidocaine will be injected into the fracture hematoma using buffered 1% lidocaine solution at a dose of 2.5 mg/kg (0.25 mL/kg), maximum dose 100 mg (10 mL). Using a 30-gauge needle to minimize pain, a small skin wheal of lidocaine will be injected over the fracture site. A 21-gauge needle will then be attached to the lidocaine filled syringe and passed through the skin wheal used to inject the lidocaine into the fracture hematoma. To confirm the needle is in the fracture hematoma, a small amount of blood from the hematoma will be aspirated into the syringe filled with lidocaine before injecting the lidocaine, as in standard practice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma Lidocaine Levels
Time Frame: Serial plasma lidocaine levels will be measured during a single subject's distal forearm fracture reduction, to be measured over the course of 60 minutes form the injection of lidocaine into the hematoma block.
Measured concentrations of plasma lidocaine levels for subjects undergoing lidocaine hematoma block for their distal radius fracture reduction.
Serial plasma lidocaine levels will be measured during a single subject's distal forearm fracture reduction, to be measured over the course of 60 minutes form the injection of lidocaine into the hematoma block.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pediatric Sedation State Scale Scores
Time Frame: This will be assessed every 60 seconds throughout the process of reduction and splinting of the subject's fracture. The scale ranges from a score of 0 to 5, with 0-1 and 4-5 being undesirable, 2-3 being desirable (appropriately sedated).
Measurement of patient overall comfort (in terms of sedation) will be assessed by an observer using the Pediatric Sedation State Scale scoring system during the reduction of the subjects fracture.
This will be assessed every 60 seconds throughout the process of reduction and splinting of the subject's fracture. The scale ranges from a score of 0 to 5, with 0-1 and 4-5 being undesirable, 2-3 being desirable (appropriately sedated).

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Satisfaction scores
Time Frame: This will be obtained immediately after procedure is complete, and will be a Likert scale from 0-10 where 0 is not satisfied at all and 10 is very satisfied.
Satisfaction with the procedure and level of provided analgesia and sedation will be assessed from the parent, subject, sedationist and orthopedist.
This will be obtained immediately after procedure is complete, and will be a Likert scale from 0-10 where 0 is not satisfied at all and 10 is very satisfied.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Washington University School of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 1, 2020

Primary Completion (Actual)

December 1, 2023

Study Completion (Actual)

December 1, 2023

Study Registration Dates

First Submitted

April 17, 2020

First Submitted That Met QC Criteria

April 20, 2020

First Posted (Actual)

April 24, 2020

Study Record Updates

Last Update Posted (Estimated)

December 18, 2023

Last Update Submitted That Met QC Criteria

December 11, 2023

Last Verified

December 1, 2023

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 202004180

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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