Trachea-noise biofeedback in asthma: a comparison of the effect of trachea-noise biofeedback, a bronchodilator, and no treatment on the rate of recovery from exercise- and eucapnic hyperventilation-induced asthma.

We review some of the evidence that supports the existence of psychosomatic triggers to bronchospasm in asthmatics, and hypothesize that it may also be possible to consciously reverse bronchospasm using trachea-noise biofeedback. We precipitated significant levels of bronchospasm in 16 asthmatics using exercise or eucapnic-hyperventilation challenges on five occasions, and administered four different treatments and a no-treatment control. The treatments were trachea-noise biofeedback (TNBF), wrong-information TNBF, an inhaled adrenergic bronchodilator, and a placebo inhaler, all given double blind. Half of the subjects had 3 training days in the use of the TNBF device before study. Our results show that TNBF, in the trained subjects only, is associated with a detectable, but not statistically significant, increase in the rate of recovery from bronchospasm over that found with no treatment. We conclude that, although asthmatics seem to have a strong ability to consciously induce bronchospasm, conscious reversal of a full asthma attack using TNBF is limited. Despite contrary conclusions by other investigators, we believe that this study demonstrated little TNBF-assisted recovery from bronchospasm. We suggest that this is because its effect may be inhibited by humoral mechanisms that sustain the attack, but we believe further work is required to support this.