In a person with COPD, an increased amount of mucus is produced due to the combination of a constant, recurring irritant, such as cigarette smoke, secondhand smoke or air pollution and a long term cough. Repeated exposure to irritants and coughing causes the airways of the lungs to become inflamed and irritated which causes narrowing and blockage of the airways. When this happens, the airways develop resistance to the airflow in the lungs making it difficult to breathe.
What is Heliox?
Heliox is a combination of two gases, helium and oxygen. In patients with COPD, heliox may reduce resistance to air flow in the airways of the lungs. Less resistance can reduce the work of breathing in the lungs of a COPD patient.
For many hospitals, however, heliox has never quite made its way into the mainstream as routine treatment for COPD. This is in spite of it's introduction into medicine in 1934 when other methods of treatment for airway obstruction were limited.
After World War II and the advent of more effective bronchodilators, heliox slipped quietly into medical obscurity where it has lived ever since. Interest into the use of heliox has only recently been renewed as a method to reduce the work of breathing in patients with COPD.
According to the results of a randomized, crossover trial reported in the April 2006 issue of the American Journal of Respiratory and Critical Care Medicine, a combination of helium and oxygen improves walking distance in patients with COPD.
While oxygen alone reduces breathlessness associated with activity, heliox reduces resistance in the lungs during exhalation which will allow COPD patients to exhale more air. This means the the lungs will be better able to eliminate carbon dioxide from the body.
In another, smaller study by Palange and Associates which was published in the November 2004 issue of The Journal of Applied Physiology, giving heliox during exercise allowed a greater amount of air to be inhaled by the lungs and reduced shortness of breath scores compared to those who were on room air. Additionally, heliox induced a state of hyperventilation, which reduced carbon dioxide levels in the blood of patients studied, thereby increasing exercise capacity.
Given that there is at least some evidence that heliox could help some patients with COPD, why, then, is it not being utilized by more doctor's offices or hospitals? The answer seems to boil down to cost, safety issues and lack of clinical evidence detailing its potential benefit.
Although helium is the second most abundant element in nature, overall costs to extract and produce it are enormous. Helium is more than 13 times as expensive as oxygen. Additionally, as many as four to six tanks of heliox may be required for 24 hours of treatment, depending upon flow rates. This bears a cost of approximately $320 to $480, which most people are unable to afford.
Because of the apparent cost issues, heliox may clearly not be indicated for every patient diagnosed with airway obstruction. Studies suggest that heliox treatment should be reserved for those with moderately severe airway obstruction that may already be amenable to medical treatment. In these types of cases, heliox can act as a bridge therapy to reduce airway resistance and the workload of breathing until other treatments are able to take effect.
Safety issues have also been raised involving the use of heliox in patients who are on ventilators. These issues need to be resolved before hospitals can begin to effectively use heliox in the treatment of ventilated patients.
There appears to be a lack of sufficient evidence from high quality studies to support routine use of heliox in the management of acute COPD. Because heliox may improve patient outcome and ultimately reduce the length of stay for hospitalized patients, further investigation should be implemented to overcome obstacles related to its use. Until that time, lack of evidence coupled with high health care costs will continue to prevent heliox from being part of mainstream medicine in the treatment for COPD.
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