Quantification of dissolved H₂ and continuous monitoring of hydrogen-rich water for haemodialysis applications: an experimental study
Mouzakis FL, Khadka LB, Pereira da Silva M, Mottaghy K. · The International Journal of Artificial Organs. 2022;45(3):254–261.
What kind of evidence is this?
Preclinical
Two-run in-vitro closed-loop sensor and gas-exchange validation experiment
Kidney and urinary health
Other forms
Not reported in this record.
Not reported in this record.
Methods at a glance
Water and 0.9% saline circulating through a laboratory extracorporeal-style circuit; no patients, animals or blood were studied.
Two principal experimental runs plus additional paired-sensor and temperature/calibration comparisons; this was a device experiment rather than a biological sample.
Each concentration was held to steady state; the H₂ sensor required roughly 50 minutes to equilibrate.
Pure cylinder H₂ was mixed with air and transferred across a membrane oxygenator into liquid flowing at 0.5 L/min.
H₂-only gas diluted with air — not Brown's gas and not inhalation.
H₂ flow was 53±2 or 53±1 mL/min at H₂:air flow ratios 1:40, 1:20 and 1:10, producing about 2.7%, 5.3% and 10.5% H₂ inlet mixtures and target dissolved ranges relevant to dialysate.
53 mL/min H₂ (reported uncertainty ±1–2 mL/min).
Air supplied the O₂; approximate air flows from the reported ratios were 2,120, 1,060 and 530 mL/min, but pure O₂ flow was not separately controlled.
Oxygen-sensor partial-pressure readings and theoretical Henry/Dalton-law estimates, plus comparisons between contactless H₂ sensors/calibration temperatures.
Outcomes and reported result
Dissolved-H₂ sensor response, accuracy/reproducibility, temperature effects, theoretical agreement and response delay.
Dissolved H₂ rose approximately linearly with feed concentration and paired devices broadly agreed at equilibrium. Important limitations were a roughly 50-minute lag, up to 30% early low-concentration divergence and increasing error at higher concentration/temperature. The article typesets equilibrium readings 47, 100 and 211 with a percent sign even though the defined sensor range and surrounding text use ppb; the units are therefore flagged as internally inconsistent.
The complete free PMC article, circuit methods, equations, figures and disclosures were checked for exact H₂ flow, air ratios, liquid versus gas flow, sensor results, unit inconsistency, limitations, funding and conflicts.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
In-vitro saline/water device study, only two principal runs, no blood/dialysis treatment, sensor not validated against gas chromatography and a likely unit-typesetting error. One author received Erasmus+/university support; authors reported no study funding and no conflicts.
Analytical monitoring for H₂-enriched dialysate preparation; it provides no evidence of clinical dialysis benefit or patient safety.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 35075943 · DOI: 10.1177/03913988211070588
Free full article in PubMed Central.
Complete PMC article and PubMed metadata; full-text extraction checked 9 August 2026.
2026-08-10