EVIDENCE LIBRARY
Can Assisted Breathing Change Alcohol Elimination? A Five-Man Pilot Study
A laboratory pilot found faster ethanol clearance during controlled isocapnic hyperpnea. The intervention, breath-based kinetics and two-person blood comparisons do not support a general sobering method or a standard DUI back-calculation rate.
A specialized breathing intervention accelerated ethanol clearance in five volunteers, but the study does not show that ordinary deep breathing makes someone fit to drive. The experiment used controlled isocapnic hyperpnea: increased ventilation while maintaining carbon dioxide. Its findings concern an assisted laboratory intervention, with major limits for individual DUI reconstruction.
What was tested
Klostranec and colleagues studied five healthy men, each on separate control and intervention days. Participants consumed 0.5 g ethanol per kilogram of body weight. During the control session they breathed normally; during the intervention session they used a specialized gas-delivery circuit after breath readings had stopped rising.
The apparatus maintained carbon dioxide while ventilation increased. This is different from unassisted hyperventilation, which can lower carbon dioxide. The experiment therefore cannot be translated into a self-administered breathing technique.
The main concentration-time series came from a breathalyzer reporting blood-equivalent alcohol values. Repeated arterial and venous laboratory blood measurements were obtained in two participants for an additional mechanistic comparison. These are distinct evidence streams.
A faster decline with different kinetics
During normal breathing, the post-peak breath-based estimates declined approximately linearly. During the intervention, their pattern was better described by exponential decline. The authors reported mean half-times of 139 minutes without intervention and 39 minutes with intervention, describing clearance as more than three times faster.
A half-time in the approximately linear control phase is concentration-dependent; it is not a fixed pharmacokinetic half-life across all alcohol concentrations. Nor should the intervention’s exponential pattern be replaced by one constant subtraction rate. The model describes an added route of elimination whose effect depends on concentration and ventilation.
The study’s ordinary-breathing and assisted-breathing curves therefore cannot be treated as interchangeable versions of a universal elimination rate. For the assumptions involved in earlier-time estimates, see the site’s retrograde BAC analysis.
Blood comparisons supported actual clearance through the lungs
A lower breath reading alone could reflect altered sampling conditions rather than a comparable reduction throughout the body. The investigators addressed that concern with simultaneous arterial and venous samples in two men.
During the intervention, venous alcohol exceeded arterial alcohol, with differences reaching approximately 20%. This supported removal of ethanol as blood passed through the lungs. After the intervention stopped, arterial or breath-based readings rebounded toward the concentrations in returning venous blood.
That rebound did not mean the body manufactured more ethanol. It reflected redistribution after an enhanced removal route was stopped. The observed levels remained below those expected without the intervention.
What the experiment did not establish
This was a proof-of-concept study, not a clinical outcome trial. It involved five healthy men with relatively mild experimentally induced intoxication. It did not establish performance in women, severely intoxicated patients, people with organ disease or drivers receiving other drugs.
The investigators interrupted the intervention before breath sampling and used repeated exhalations to reduce sampling differences. Nevertheless, most kinetic conclusions relied on breath as a surrogate for blood. The two-person blood comparison supports the mechanism without providing population-wide prediction limits.
The paper also disclosed commercial interests: several authors were employees or shareholders of the company developing the device, which supplied a unit without charge. That does not negate the observations, but it matters when weighing a small pilot against the need for independent replication.
The DUI relevance is conditional
If a person actually received a specialized intervention that changes elimination, a reconstruction should document its timing and effects rather than silently apply an ordinary untreated curve. This study does not justify assigning its average effect to a person who merely breathed rapidly.
No driving, judgment or recovery-of-function test was performed. Faster measured clearance is not evidence of restored driving ability at a particular moment, and the study did not validate a safe-to-drive concentration. The site’s blood–breath agreement discussion explains another reason to preserve the distinction between specimen results and breath-based estimates.
Primary source
Klostranec JM and colleagues. Accelerated ethanol elimination via the lungs. Scientific Reports. 2020;10:19249. https://doi.org/10.1038/s41598-020-76233-9.