It certainly makes sense: COPD sufferers have varying degrees of serious breathing difficulties, which keeps them from almost any kind of exercise, especially in advanced stages. So maybe “lighter than air” air would be easier to breath, reduce shortness of breath and perhaps even allow them to do some exercise with all of its physical and mental benefits.
A group of Italian researchers reports in the November issue of the Journal of Applied Physiology that while breathing a low-density mixture of 79% helium and 21% oxygen (called heliox), the length of time that 12 COPD patients could do real exercise was 9 minutes, versus only 4.2 minutes for 12 patients breathing regular air (79% nitrogen/21% oxygen). And the exercise involved wasn’t trivial: The subjects cycled “until exhaustion” at a rate of 50 rpm at 80% of their maximal rate measured several days earlier while on air.
The World Health Organization estimates that chronic obstructive pulmonary disease (COPD, defined as emphysema and chronic bronchitis) as a single cause of death around the world shares fourth place with HIV/AIDS, following coronary heart disease, cerebrovascular disease and acute respiratory infection. WHO estimates that 2,740,000 people died of COPD worldwide in 2000; cigarette smoking is blamed for about 85% of cases.
According to the National Heart, Lung, and Blood Institute (NHLBI), COPD is the fourth leading cause of death in the U.S. and is projected to rise to third place for both men and women by the year 2020. NHLBI says 12.1 million Americans 25 and older were diagnosed with COPD in 2001. Estimated cost of COPD in 2002 was $32.1 billion, of which $18 billion were direct costs.
COPD is characterized by shortness of breath (dyspnea) and exercise intolerance. Among severely affected patients, especially those with emphysema, the inability to exercise or even to move small distances is mostly due to limits on “breathing out” because of limited expiratory flow, and early onset of dyspnea.
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, Università “La Sapienza,” Rome, Italy.