Breathing Hydrogen Gas Protects Lungs from Ventilator Damage
- Authors
- Chien-Sheng Huang, Tomohiro Kawamura, Sungsoo Lee, Naobumi Tochigi, Norihisa Shigemura, Bettina M. Buchholz, John D. Kloke, Timothy R. Billiar, Yoshiya Toyoda, Atsunori Nakao
- Journal
- Critical Care
- Year
- 2010
- DOI
- 10.1186/cc9389
- Study Type
- Mouse
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- United States
- Health Condition
- Ventilator-Induced Lung Injury
- Body System
- Respiratory
TL;DR
Inhaling hydrogen gas can significantly reduce lung damage caused by mechanical ventilators used in intensive care.
Key Finding
In mechanically ventilated mice, inhaled hydrogen gas significantly reduced lung swelling, inflammatory cell infiltration, and cell death compared to control treatment.
Summary
Mechanical ventilation (a machine that helps patients breathe in hospitals) can damage the lungs by triggering inflammation and oxidative stress (cellular damage from unstable molecules). Researchers tested whether inhaled hydrogen gas could protect mouse lungs from this damage. Mice on mechanical ventilators that breathed 2% hydrogen showed significantly less lung swelling, fewer inflammatory cells, and less cell death compared to mice breathing regular air, suggesting hydrogen's antioxidant properties helped reduce injury.
Practical Takeaway
This is an early-stage animal study showing hydrogen inhalation may help protect lungs during mechanical ventilation, but results in mice do not directly translate to humans. Much more research, including human clinical trials, would be needed before hydrogen could be considered a therapeutic option for ventilator patients in intensive care settings.
Abstract
Abstract Introduction Mechanical ventilation (MV) can provoke oxidative stress and an inflammatory response, and subsequently cause ventilator-induced lung injury (VILI), a major cause of mortality and morbidity of patients in the intensive care unit. Inhaled hydrogen can act as an antioxidant and may be useful as a novel therapeutic gas. We hypothesized that, owing to its antioxidant and anti-inflammatory properties, inhaled hydrogen therapy could ameliorate VILI. Methods VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg without positive end-expiratory pressure, FiO2 0.21). The mice were randomly assigned to treatment groups and subjected to VILI with delivery of either 2% nitrogen or 2% hydrogen in air. Sham animals were given same gas treatments for two hours (n = 8 for each group). The effects of VILI induced by less invasive and longer exposure to MV (tidal volume of 10 ml/kg, 5 hours, FiO2 0.21) were also investigated (n = 6 for each group). Lung injury score, wet/dry ratio, arterial oxygen tension, oxidative injury, and expression of pro-inflammatory mediators and apoptotic genes were assessed at the endpoint of two hours using the high-tidal volume protocol. Gas exchange and apoptosis were assessed at the endpoint of five hours using the low-tidal volume protocol. Results Ventilation (30 ml/kg) with 2% nitrogen in air for 2 hours resulted in deterioration of lung function, increased lung edema, and infiltration of inflammatory cells. In contrast, ventilation with 2% hydrogen in air significantly ameliorated these acute lung injuries. Hydrogen treatment significantly inhibited upregulation of the mRNAs for pro-inflammatory mediators and induced antiapoptotic genes. In the lungs treated with hydrogen, there was less malondialdehyde compared with lungs treated with nitrogen. Similarly, longer exposure to mechanical ventilation within lower tidal volume (10 mg/kg, five hours) caused lung injury including bronchial epithelial apoptosis. Hydrogen improved gas exchange and reduced VILI-induced apoptosis. Conclusions Inhaled hydrogen gas effectively reduced VILI-associated inflammatory responses, at both a local and systemic level, via its antioxidant, anti-inflammatory and antiapoptotic effects.