Heliox appears to positively change multitude of lung mechanics
In the current study, the more than doubling in the time COPD patients could exercise "was associated with a significant reduction in lung dynamic hyperinflation (DH) at isotime (Iso; when the patients stopped exercising during regular air breathing), as reflected by the increase in inspiratory capacity (IC) to 1.97 from 1.77 liters and a decrease in dyspnea" scoring to 6 from 8.
The researchers said that "heliox induced a state of relative hyperventilation as reflected by the increase in minute ventilation" to 38.3 versus 35.5 liters, and minute ventilation over carbon dioxide output to 36.3 versus 33.9 at peak exercise, and by the reduction in arterial partial pressure of carbon dioxide at Iso to 44 from 48 and at peak exercise to 46 from 48.
The study, "Effect of heliox on lung dynamic hyperinflation, dyspnea, and exercise endurance capacity in COPD patients," was conducted by Paolo Palange, Gabriele Valli, Paolo Onorati, Rosa Antonucci, Patrizia Paoletti, Alessia Rosato, Felice Manfredi, and Pietro Serra from Dipartmento di Medicina Clinica, Servizio di Fisiopatologia Respiratoria, Universit "La Sapienza," Rome, Italy.
Palange et al. says the "most likely explanation for our finding is that heliox improved maximal expiratory flow and maximal ventilatory capacity, as reflected by the increase in resting forced expiratory volume and by the increase in tidal volume, mean expiratory flow, and minute ventilation at peak exercise. Importantly, the improvement in maximal expiratory flow determined a significant reduction in lung dynamic hyperinflation and dyspnea, as reflected by the significant increase in inspiratory capa