Expiratory breathing techniques

In resume, inspiratory breathing exercises coupled with mobilization and body positioning are used to increase lung volumes and improve ventilation. They can promote relaxation and reduce anxiety. Expiratory breathing techniques with an open glottis (a huff) or with a closed glottis (a cough) are used to increase expiratory flow rates and, thus, enhance airway clearance. Forced expiratory maneuvers should be used with caution in patients with bronchospasm to avoid exacerbation of spasm, or cardiac dysfunction. 

All the static lung volumes and capaeities except FRC and RV can be measured directly through use of a simple spirometer (an apparatus traditionally consisting of a cylindrical bell immersed in water and equipped with outlets that a person can breathe into, or inhale from, to measure expiratory or inspiratory volumes). Functional residual capacity and RV are measured indirectly by using several alveolar gas dilution techniques. 

Figure 4 Cartoon depicting technique for quantification of nebulizer output and measurement of deposition. On the left, a patient inhales nebulized particles via a Y piece. The exhalation filter captures exhaled particles. On the right, the same patient performs a similar maneuver. The inhaled mass filter captures particles that would have been inhaled. Differences between filters measure deposition. Breathing pattern can be monitored using a pneumotachograph represents the sum of minute ventilation plus nebulizer flow leaving the expiratory arm of the Y piece). (From Ref. 9.)...

FIGURE 17.8 Arrangement of equipment for the nitrogen-washout technique. Valve V allows the subject to breathe room air until the test is started. The test is started by operating valve V at the end of a normal breath, that is, the subject starts breathing 100% Oj through the inspiratory valve (I) and exhales the Nj and Oj mixture into a collecting spirometer via the expiratory valve EX. 

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