Clinical research for ‘hydrogen inhalation therapy’ in more than 10 hospitals across Japan has proved it can help patients who have suffered from cardiac arrests.

The research, initially conducted on laboratory rats in 2012, proved that damage to brain functions and heart muscle tissues was reduced by inhaling hydrogen (H2) after cardiopulmonary resuscitation.

The research accelerated from February this year, and patients who had been resuscitated after cardiopulmonary arrest were given a mixture of 98% O2 and 2% H2 to inhale for up to 18 hours. The research, which is based on a random patient selection process, will continue to be conducted for a further two years with a total of 360 individual cases examined.

Prof. Masaru Suzuki, Department of Emergency and Critical Care Medicine at Keio University Hospital, explained the details of the clinical study, “It is called the Double Blind Method – we are kept completely uninformed as to which patient has inhaled H2. We are conducting 360 cases, of which half inhale H2 and half do not. The half that do not inhale H2 undergo regular treatment.”

If there is a clear effect, H2 will become a gas medicinal product which will have a big impact in the field of cardiopulmonary resuscitation

“We began research in 2013 to see if H2 could be skilfully mixed in with the O2 and air that the patient inhales and we did experiments to see if it could feasibly be administered to patients.” 

“Common ventilators usually use platinum sensors for flow measurements but platinum actually becomes a catalyst when H2 is passed through so it cannot be used in this case. Instead, an ultrasonic type sensor was employed to monitor flow measurements.”

“A premixed gas composed of 96% N2 and 4% H2 from a cylinder is mixed with O2 from ventilators prior to patient inhalation. Inserting more than 4% H2 directly into O2 is dangerous on account of the explosion threshold, so at this stage we are using just 2% of H2.”

Suzuki continued and explained, “Medication dissolves in the blood and is carried throughout the body and there is the possibility that H2 diffuses without relying on blood flow, meaning it can easily pass through the blood brain barrier and even into the brain cells themselves. Additionally, because the heart and lungs are close to each other, when inhaled, H2 has the potential to reach the heart via diffusion, which can then be carried throughout the body.”

“Through experiments on animals, we have discovered that the positive effects from H2 inhalation is high. We would like to clarify these effects on people and verify the effectiveness of this method of treatment.”

medical gases

“If there is a clear effect, H2 will become a gas medicinal product which will have a big impact in the field of cardiopulmonary resuscitation. Research is moving fast across the world and it will eventually become a combined international investigation.”

“If this H2 inhalation therapy works with cardiopulmonary arrest, it would mean that even under the most severe conditions this treatment is effective. I think the potential for H2 in medical uses will spread endlessly on the back of this medical research,” he concluded.