Systemic Absorption of Lidocaine After Hematoma Block

• Status: Recruiting
• Trial end date: 2021-05-01
• Target enrollment: 0
• Participant gender: All

Summary

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, size of the fracture hematoma and effectiveness of pain control during fracture reduction.

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, if there this a correlation between fracture type and fracture hematoma size, 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. They believe that a more displaced fracture will have a larger hematoma, that a larger hematoma will be associated with a higher peak blood lidocaine level, and that a higher peak blood lidocaine level will be associated with more successful pain control scores and satisfaction with the procedure.

• Phase: Phase 4
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Washington University School of Medicine
• Treatments: Lidocaine

Criteria

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