Effects of Combined Respiratory Muscle Training and Steam Inhalation

Numerous respiratory muscle training (RMT) experiments with healthy subjects, as well as with patients of chronic obstructive pulmonary disease (COPD), bronchiectasis and asthma, have been reported since 80's. Respiratory training with WellO2 device was used in a clinical pilot study by Huttunen and Rantala to investigate effects of steam inhalation and RMT on voice quality in patients with voice symptoms. No adverse effects were found in that study.

The present study is designed to investigate further the RMT and steam inhalation on lung function and respiratory symptoms with subjects suffering from obstructive diseases such as asthma and COPD. The results may be used later in statistical power calculations and to determine the endpoints of larger clinical trial with the investigational device.

Asthma is still an increasing problem in many countries, even though, incidence of the most severe asthma cases is in decline due to earlier diagnosis, better control and earlier intervention practices. The prevalence of asthma and COPD in western countries is around 10 % and 5 %, respectively. The prevalence of COPD is higher in the countries where smoking and poor quality of inhaled air are common.

The treatment of asthma is based on treatment of eosinophilic inflammation of the airways by inhaled corticosteroids and on treatment of bronchoconstriction by sympathomimetic bronchodilators, short-acting and long-acting. The drugs may, however, induce side effects like voice disorders and cardiac symptoms (palpitation, tachycardia and extrasystoles).

Therefore, in many cases the doses of the drugs cannot continuously be kept at the highest effective level. Therefore, non-pharmacological methods can complement the treatment portfolio. The breathing physiotherapy by respiratory muscle training and warm steam inhalation can offer an additive treatment method for patients with airway obstruction.

It is possible that training with the combination of positive counter pressure and steam inhalation methods can induce significant improvement in ventilatory function variables and respiratory symptoms in asthmatics who have kept their ordinary pharmacological therapy at a constant level. Based on the previous scientific evidence found on the public domains, it can be expected that the respiratory muscle strength will be increased offering a possibility for more effective pulmonary mechanics, ventilation and lung volumes. In addition, exhaling against resistance will induce a positive end expiratory pressure (PEEP) effect which can open narrowed airways and make the distribution of alveolar ventilation less heterogeneous. This can improve gas exchange in the lungs and increase the level of low oxygen saturation in arterial blood.

In COPD, drugs can improve the airway changes, irreversible thickening of the airway walls, and chronic inflammation only partially. Therefore, breathing physiotherapy may offer an additive method to improve lung function and gas exchange, and to diminish dyspnoea and other symptoms like cough. The mechanisms of RMT are principally the same in asthma and COPD. Patients with obstructive airway disease frequently have both COPD and asthma, partly reversible or irreversible.