Fatigue in post-acute sequelae of SARS-CoV2 (PASC) treated with oxygen-ozone autohemotherapy, preliminary results on 100 patients
Tirelli U, Franzini M, Valdenassi L, et al. European Review for Medical and Pharmacological Sciences, 2021.
- Study type
- Case series
- People studied
- 100 people
- Population
- Patients with post-COVID fatigue
- Published
- 2021, European Review for Medical and Pharmacological Sciences
- Identifiers
- PMID 34604980, DOI 10.26355/eurrev_202109_26809
What the authors reported
In 100 patients with post-COVID fatigue, a preliminary, uncontrolled series of oxygen-ozone autohemotherapy reported reduced fatigue scores after treatment.
What limits this result
No comparison group, so how much of the change would have occurred anyway cannot be determined; preliminary results from ozone-therapy society-affiliated authors.
Other ozone methods, such as major autohemotherapy, that clinics cite in support of EBO2. A result for one method does not transfer automatically to another. One study rarely settles a medical question; our guides weigh each paper against the rest of the evidence.
How the study was done
- Design
- Clinical multicenter case series study, described as a brief report
- Setting
- Outpatients recruited from two clinics, Pordenone and Bergamo
- Read from
- Read from the full text of the paper. Read on September 28, 2026.
Source: The paper at europeanreview.org
Study arms
| Group | Participants | What they received |
|---|---|---|
| Patients with PASC-related fatigue | 100 | Oxygen-ozone autohemotherapy |
Source: The paper at doi.org
Procedure as reported
- Ozone concentration
- 40-50 mg/150-200 ml ozone
- Blood volume
- 150/200 ml blood
- Sessions
- Usually 2-3 major treatments each week for 2–3 weeks
In the paper's own units, not converted.
Source: The paper at europeanreview.org
What it measured
- Fatigue Severity Scale (FSS): reduction in PASC symptoms
- Reduced by 67%, as a mean, in all the investigated cohort of patients (H = 148.4786, p < 0.0001)
- Improvement from FSS = 7 to FSS = 3 (a statement in the Discussion)
- At least 85% of the patients experienced an improvement from FSS = 7 to FSS = 3
in about 36% of PASC patients but at least 85% of them experienced an improvement from FSS = 7 to FSS = 3
- Recovery from PASC-associated fatigue
- Quite completely recovered: about two fifths (around 40%) of the whole cohort undergoing ozone treatment
- Health status after treatment
- All treated patients, except three of them (with very modest changes), strongly ameliorated their health status
- Effect by sex
- Most patients were female; the effect was not influenced by sex distribution (H = 0.7353, p = 0.39117)
- Effect by age
- Significant effects did not depend on age distribution, in very old patients (≥ 75 years old) or in youngest ones (≥ 50 years old)
- Duration of recovery (a statement in the Discussion)
- The recovery from PASC lasted also several months following therapy
Sources: The paper at doi.org, The paper at europeanreview.org
Follow-up
FSS interview at least one week after the treatmentsFollowing treatments, patients were interviewed with FSS at least one week later, to avoid placebo effects
Source: The paper at europeanreview.org
Funding and conflicts
The authors state they have no conflicts of interest
Source: The paper at europeanreview.org
Where we cite this study
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