Inspiration boosters: technical updates in incentive spirometers and breath-stacking

Abstract

TInspiration boosting techniques were proposed in order to promote sustained maximal inspirations, creating high ventilation pressures and preventing alveolar collapse. Incentive spirometers are classified as volume-dependent or flow-dependent, possessing visual biofeedback mechanism and requiring patient cooperation for the effectiveness of the technique. An alternative mechanism for inspiration boosting that can be used with uncooperative individuals is called breath-stacking. This review aims to collate the current knowledge about volume or flow-dependent incentive spirometers and the breath-stacking technique, comparing the different incentive spirometers to one another to the breathstacking technique. The volume-dependent incentive spirometers have advantages with regard to providing lower respiratory rate, smaller tidal volume, larger displacement of the abdominal compartment, and less additional work of breathing in relation to flow-dependent incentive spirometers. In comparison with incentive spirometers, the breath-stacking technique achieves better inspiratory capacity and longer lung expansion. Furthermore, breath-stacking has the advantage of not depending on the individual's cooperation and providing significant lung volumes and promoting better support of maximum inspiration.

Comparison of the effects of voluntary and involuntary breath stacking techniques on respiratory mechanics and lung function patterns in tracheostomized patients: a randomized crossover clinical trial

“… 18 The two techniques studied here make it possible to maintain lung expansion longer, allowing additional time for the forces of interdependence to recruit volume, a process that does not usually take place during a single inspiratory effort. 19 …”

“…At this point, the lung volume is close to total lung capacity. 7 , 19 One study compared the resting IC, the resting IC with a breath hold, and VBS in 26 cooperative patients in whom pain or muscle weakness resulted in impaired ability to achieve or sustain deep inspiration. VBS increased inspiratory volume, indicating that the addition of a one-way valve is effective in increasing IC.…”