Effects of Noninvasive Ventilation Compared to Salbutamol in Respiratory Mechanics and Lung Function of Asthmatics After Bronchoprovocation: Randomized Cross-over Trial

Asthma is a chronic inflammatory disease characterized by recurrent episodes of reversible airway obstruction. The drug treatment typically includes inhaled steroids and bronco dilators. These acute episodes of bronchoconstriction can, for the most part, attend with hyperinflation, the hyperinflation and the consequent increase of functional residual capacity (FRC) inspiratory muscle activation in phase before the expiratory lung elastic equilibrium and rib cage.

Some studies reports the injury to respiratory function that causes acute hyperinflation with a reduction of the contribution of the abdominal compartment and increased assistance from the chest compartment, thereby reducing the efficiency mechanics of the diaphragm in response to decreased your stamping area. As a result of this disadvantage and mechanics "reduction of curvature" of the diaphragm expiratory muscle activation occurs in an attempt to restore the original mechanics and thus your primary function.

Some studies have investigated the effects of bronchoconstriction in recruitment of the respiratory muscles and respiratory mechanics of patients susceptible to asthma. As asthma has distinct characteristics in crisis and in stable phase, testing of bronchial provocation test have been part of the studies allowing assessment in different physiological conditions, close to an acute condition without necessarily a crisis and insufficiency that would make it really an assessment respiratory kinematics and the involvement of the thoracic and abdominal compartments in each of these phases and mainly in front of any therapy.

Bronchial provocation tests are safe once they cause the release of endogenous mediators that cause the bronchial smooth muscle contraction causing narrowing of the airway, but as your sensitivity is reduced your action is completely reversed with use of bronchodilator and the positive response to these tests that can be performed by exercise or inhaling hypertonic solution 4.5% reflect a inflammation of the Airways.

The interest in the implementation of non-pharmacological therapies and especially the knowledge of resources used often to relieve the overload of respiratory muscles in patients with obstructive, since the Decade of 80, has been demonstrating that the use of expiratory positive pressure can reduce muscle work and reduce the volume of expiratory reserve contributing to deflation.