Optimal Number of Hyperbaric Oxygen Treatments for Carbon Monoxide Poisoning

NCT06619717 | Terminated

• 1 other identifier: Pro00146529
• Study Type: interventional
• Target: 2
• Locations: 1 country
• Sites: 1

Brief Summary

The optimal treatment strategy with hyperbaric oxygen therapy has been the subject of some debate over the past 3 decades. Initial landmark studies showed a decrease in the incidence of DNS with a single treatment and also with three treatments over the course of 24 hours. These two strategies have continued to be used widely without further evidence comparing them in a direct fashion. Retrospective publications in the years since have been largely conflicting about the benefit of additional hyperbaric treatments. The investigators would seek to randomize patients with carbon monoxide poisoning to receive with 1 or 3 treatments with hyperbaric oxygen and measure their neurologic outcomes.

Conditions

Hyperbaric Oxygen Therapy; Carbon Monoxide Poisoning

Outcome Measures

Primary Outcomes (1)

• Proportion of patients experiencing delayed neurologic sequalae

  DNS includes a spectrum of symptoms such as depression, anxiety, memory issues, ataxia, behavioral changes, decreased cognitive function. For CO-poisoned patients who do not succumb to the direct effects of hypoxia, DNS is one of the primary causes of long-term morbidity. The presence of delayed neurologic sequelae as measured by a series of standardized tests. These tests will include digit span (Attention), the Boston Naming Test 15 (aphasia), general orientation and delayed recall (memory), and clock drawing (visuospatial). DNS will be considered present if a patient scores ≥2 SD below the standardized T scores for any neuropsychological test, if they score ≥1 SD below the standardized T scores for 2 or more tests, or if they score ≥1 SD below the standardized T score for any test and self-report poor memory/concentration/attention.

  6 weeks and 6 months

Study Arms (2)

Single HBO treatment

ACTIVE COMPARATOR

The exact parameters of each dive will be left to individual clinicians. Commonly used treatments would be: 1 treatment: 100% oxygen at 2.8 atmospheres for 30 minutes followed by a 10-minute air break, then 100% oxygen at 2 atmospheres for 60 minutes with one 10-minute air break after 30 minutes

Procedure: Hyperbaric Oxygen Therapy

Three HBO treatments

EXPERIMENTAL

The exact parameters of each dive will be left to individual clinicians. Commonly used treatments would be: 3 treatments: Weaver protocol or similar variation (i.e. 100% oxygen at 3 atmospheres for 90 minutes with two 10-minute air breaks every 30 minutes. This will be repeated every 8 hours until 3 treatments are complete.)

Procedure: Hyperbaric Oxygen Therapy

Interventions

Hyperbaric Oxygen Therapy PROCEDURE

Three treatments with hyperbaric oxygen therapy. The exact parameters of each dive will be left to individual clinicians. Commonly used treatments would be: Weaver protocol, or similar (i.e. 100% oxygen at 3 atmospheres for 90 minutes with two 10-minute air breaks every 30 minutes. Repeat this every 8 hours until 3 treatments are complete.)

Three HBO treatments

Eligibility Criteria

• Age: 17 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• All adult (over 17 years old) patients referred to a Hyperbaric Unit for acute carbon monoxide poisoning.

You may not qualify if:

• Obtunded
• Mechanically ventilated
• Pregnant
• Incarcerated
• Cognitively impaired (acutely or chronically)

Sponsors & Collaborators

• University of Alberta: lead

Study Sites (1)

University of Alberta

Edmonton, Alberta, T6G2R3, Canada

Location

MeSH Terms

Conditions

Carbon Monoxide Poisoning

Interventions

Hyperbaric Oxygenation

Condition Hierarchy (Ancestors)

Gas Poisoning; Poisoning; Chemically-Induced Disorders

Intervention Hierarchy (Ancestors)

Oxygen Inhalation Therapy; Respiratory Therapy; Therapeutics

Study Officials

• Brian Rowe, MD, MSc, CCFP (EM), FCCP

  Professor in the Department of Emergency Medicine, Faculty of Medicine & Dentistry, College of Health Sciences, at the University of Alberta

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 26, 2024
• First Posted: October 1, 2024
• Study Start: January 24, 2025
• Primary Completion: February 10, 2026
• Study Completion: February 10, 2026
• Last Updated: March 13, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)