Research Review: Canadian Hyperbaric Oxygen Research 2020 to 2025

2025

The 2025 open-access output leans toward methods and safety rather than efficacy testing. Yoo and colleagues published a cross-sectional study of the quality of reporting in hyperbaric medicine clinical trials, continuing a Canadian thread of research-on-research. Park and colleagues reported a retrospective cohort on the safety of HBOT in non-emergent patients with a history of seizures, and Spiegel and colleagues compared adjunctive HBOT with intratympanic steroids in sudden sensorineural hearing loss in a retrospective study. The year also included a case report by Vallélian and colleagues on highly concentrated hydrogen peroxide poisoning with portal venous gas treated with HBOT. The mix is characteristic of the wider Canadian set: observational designs, safety questions, and single-case experience predominate over prospective efficacy trials.

2024

This was the most productive open-access year in the set. Safety and pre-treatment work-up featured strongly: Brenna and colleagues examined the role of routine cardiac investigations before HBOT, and Schiavo and colleagues reported a retrospective cohort on the safety of HBOT in patients with heart failure. Efficacy-oriented work appeared in conditions that remain investigational rather than approved: Harrison and colleagues reported a randomised controlled trial of HBOT after established stroke, and Marois and colleagues compared different doses of hyperbaric treatment against conventional therapies in children with cerebral palsy. Case-based work included Khan and colleagues on HBOT during pregnancy for critical anaemia secondary to sickle cell disease, and Yu and colleagues on a radiation-induced chest-wall ulcer. Methods and reporting research continued through van Ierssel and colleagues (reporting completeness in concussion intervention trials), Khan and colleagues (database searching to identify HBOT randomised trials), and a diving-medicine review by Blake and colleagues.

2023

The 2023 set is weighted toward case reports, narrow clinical questions, and education. Schiavo and colleagues produced a clinical guideline review on implanted neurological devices in patients undergoing HBOT, and Brenna and colleagues contributed both a case report on neurological injury after complex spinal surgery and a longitudinal observational study of pulmonary function following HBOT. Malhotra and colleagues reported intraoperative air embolism after craniotomy treated with HBOT, one of several Canadian air-embolism reports across this period. Talbot and colleagues surveyed hyperbaric medicine teaching in Canadian undergraduate medical curricula, and Ponzano and colleagues published a scoping review touching on spinal cord injury. Air embolism is a recognised Health Canada indication; much of the rest of this year's work addresses peri-treatment safety and training rather than efficacy.

2022

In 2022 the open-access output combined evidence synthesis with case experience. Boet and colleagues published a living systematic review update on HBOT for COVID-19 pneumonia, an investigational use that drew sustained Canadian attention during the pandemic, alongside a Delphi study toward an international hyperbaric medicine simulation curriculum. Brenna and colleagues reviewed the role of routine pulmonary imaging before HBOT, extending the group's pre-treatment safety work. Case and mechanistic reports rounded out the year: Jalilian and colleagues described HBOT for a late ischaemic complication of cosmetic hyaluronic acid filler, and Richardson examined oxygen and radiation-induced cataract in a basic-science context. The systematic-review and safety strands are the most visible Canadian contributions this year.

2021

The 2021 set is the second largest and is dominated by retrospective safety analyses and case reports. Schiavo and colleagues contributed a narrative review on the mechanistic rationale and clinical efficacy of HBOT in chronic neuropathic pain, an investigational indication, and Boet and colleagues published a systematic review of HBOT for COVID-19 pneumonia. Cardiac and haemodynamic safety featured through Vincent and colleagues, who studied HBOT in patients with reduced left ventricular ejection fraction. Other entries were case-based or modelling work: Helmeczi and colleagues on penile calciphylaxis, Hadjadj and colleagues on an air embolism during a cardiac procedure, Nepon and colleagues on radiation-induced tissue damage, and Dulai and Jairath on a microsimulation model of HBOT for ulcerative colitis flares. Several of these address recognised indications (air embolism, radiation tissue injury), while others are investigational.

2020

The earliest year in this review centres on retrospective safety work and surgical or neurological applications. Schiavo and colleagues reported a retrospective study of blood pressure changes during HBOT and, separately, a feasibility study pairing HBOT with focused rehabilitation for upper-limb motor function after stroke. Boet and colleagues published a systematic review asking whether preventive HBOT can improve surgical outcomes, and Aldrees and Micieli described radiation-induced optic neuropathy. As with later years, the designs are predominantly observational, exploratory, or synthesis papers rather than definitive efficacy trials.

What the Canadian evidence base looks like

Read across the six years, several patterns stand out, all bibliometric rather than evaluative. First, the open-access Canadian output is concentrated in observational and descriptive designs: retrospective cohorts, case reports, and narrative or systematic reviews far outnumber randomised controlled trials. Second, a substantial share of the work is about HBOT delivery and safety rather than about treating a disease, covering pre-treatment cardiac and pulmonary work-up, blood-pressure and seizure safety, implanted devices, and trial-reporting quality. Third, much of the disease-directed research addresses investigational or off-label uses (stroke, cerebral palsy, neuropathic pain, COVID-19 pneumonia, ulcerative colitis) rather than the approved Health Canada indications, and where approved indications appear they tend to surface as single case reports (air embolism, radiation tissue injury) rather than as Canadian-led efficacy trials.

The gaps follow from this. Several recognised indications are thinly represented or absent in the Canadian open-access set, and the approved indications that do appear are documented mainly through case experience rather than prospective Canadian trials. The relatively high count of safety and methods papers reflects the interests and capacity of a small number of academic hyperbaric units, not the relative effectiveness of any treatment. A reader should not infer, from the volume or recency of studies on a given topic, anything about whether HBOT helps that condition. This map shows where Canadian groups have chosen to look, and with what tools, and nothing more.

How to use the research list below

The list that follows contains every Canadian-led HBOT study in the Canada Hyperbarics database that was published in 2020 or later and has a freely available full-text version, each linked directly to that full text. "Canadian-led" means a first or last author based in Canada. Paywalled and abstract-only studies are excluded, as are retracted studies. This is a reference list, not a set of summaries, and inclusion does not imply that a study supports HBOT for the condition it examines; many describe investigational uses, safety questions, or single cases. Read each study in full and weigh its design before drawing any clinical conclusion. Counts and the open-access set refresh each quarter.