D'hoore Leen, Germonpré Peter, Rinia Bert, Caeyers Leonard, Stevens Nancy, Balestra Costantino
Centre for Hyperbaric Oxygen Therapy, Queen Astrid Military Hospital, Brussels, Belgium.
DAN Europe Research Division, Roseto, Italy and Brussels, Belgium.
Diving Hyperb Med. 2025 Jun 30;55(2):104-113. doi: 10.28920/dhm55.2.104-113.
Long COVID syndrome is a major health issue. Multiple treatments have been proposed but efficacy is inadequately investigated. Hyperbaric oxygen therapy (HBOT) has been promoted based on a small number of publications. As there is potential for a placebo effect and the financial cost of HBOT is high, we sought to investigate the effects of HBOT in Long COVID in a randomised trial.
We randomised 101 patients into four treatment groups, receiving 10 sessions of oxygen 'treatment' inside a pressure chamber, according to one of four modalities: A - 100% oxygen at 253 kPa (2.5 atmospheres absolute); B - 40% oxygen at 253 kPa; C - 100% oxygen at 101.3 kPa (1 atmosphere absolute); D - 21% oxygen at 101.3 kPa. Groups B and C thus received a similar effective oxygen dose of 101.3 kPa. Quality of life symptom scores (Visual Analogue Scale; EQ-5D-5L, C19-YRSm), a 6-minute walking test and five neurocognitive tests were administered before and after the treatment series. At three months post-treatment, a telephone questionnaire probed for lasting effects.
All groups were comparable with regards to demographics, Long COVID symptoms and severity. After treatment, there were no significant differences in subjective symptoms, functional scores, and cognitive performance between any groups. The response to treatment was highly variable, with some patients in even the 'placebo' group D reporting a significant improvement in their well-being. This was not reflected in any objective outcome scores. No subgroups of patients responded better to any of the treatments.
There was no significant effect from different doses of oxygen in a hyperbaric chamber. It is possible that the very modest improvements reported in other studies were due to a placebo effect. Claims that HBOT has a significant effect on Long COVID need further investigation before indiscriminately prescribing or promoting HBOT.
新冠后综合征是一个重大的健康问题。已经提出了多种治疗方法，但疗效尚未得到充分研究。基于少数出版物，高压氧疗法（HBOT）得到了推广。由于存在安慰剂效应的可能性，且HBOT的经济成本很高，我们试图在一项随机试验中研究HBOT对新冠后综合征的影响。
我们将101名患者随机分为四个治疗组，根据四种模式之一，在压力舱内接受10次氧气“治疗”：A组——在253 kPa（2.5个绝对大气压）下吸入100%氧气；B组——在253 kPa下吸入40%氧气；C组——在101.3 kPa（1个绝对大气压）下吸入100%氧气；D组——在101.3 kPa下吸入21%氧气。因此，B组和C组接受了相似的有效氧剂量101.3 kPa。在治疗系列前后进行生活质量症状评分（视觉模拟量表；EQ-5D-5L，C19-YRSm）、6分钟步行试验和五项神经认知测试。在治疗后三个月，通过电话问卷询问持续效果。
所有组在人口统计学、新冠后症状和严重程度方面具有可比性。治疗后，任何组之间在主观症状、功能评分和认知表现方面均无显著差异。对治疗的反应高度可变，甚至“安慰剂”D组的一些患者报告其幸福感有显著改善。但这在任何客观结果评分中均未体现。没有患者亚组对任何一种治疗反应更好。
高压舱内不同剂量的氧气没有显著效果。其他研究中报告的非常轻微的改善可能是由于安慰剂效应。在不加区别地开处方或推广HBOT之前，关于HBOT对新冠后综合征有显著影响的说法需要进一步研究。
