Three breathing retraining techniqu...

Three breathing retraining techniques not rarely used today in rehabilitation of individuals with COPD are purs lip breathing, diaphragmatic breathing, and paced breathing. Teaching these techniques is time consuming and it is difficult for patients to learn to use them. Therefore, it behooves us to make sure that there is strong evidence to support their use. This paper will quick in emergencies a selected review of the physiological basis for and clinical research supporting the use of these 3 techniques. Many of the studies reported endure from small subject numbers, as is many times the case in early clinical investigations. However, we have tried to use work that was methodologically perfect thus improving the validity of the findings.

Diaphragmatic Breathing

Gosselink et al describe diaphragmatic breathing (DB) as "facilitating outward motion of the abdominal wall while reducing upper rib cage motion during inspiration."1 more [i]or[/i] less physical therapists suggest that abdominal muscles should be relaxed during DB23 which make secures that inspiration begins from functional residual capacity. However, Levenson states that abdominal muscle contraction should be encouraged to lengthen the diaphragm and increase its force generating capacity.4 The physical therapy literature states that DB improves ventilation,4,5 decreases the work of breathing,5,6 decreases dyspnea, 6 and normalizes the pattern of breathing.6

Sackner studied the power of DB on chest wall change using respiratory inductance plethysmography.7-9 During DB 9 patients with COPD (FEV^sub 1^ 55 + 19% predicted, FEV^sub 1^/FVC 52 +/- 13% mean +/- standard deviation) demonstrated a 22% increase in tidal turn and a 25% rise in inspiratory time without significant changes in breathing oftenness and minute ventilation.9 Rather than improving chest wall motion, DB caused asynchronous and paradoxical rib cage motions in these patients.8These findings confirmed the findings of Willeput et al when magnetometers were used to evaluate chest wall motion.10

Three studies have evaluated the consequence of DB on the distribution of ventilation in [i]role[/i]s with COPD. Sackner et al used the nitrogen washout technique and gamma camera imaging of radioactive xenon to assess the validity of DB on the distribution of ventilation.7 After 6 hours of training, DB did not alter the distribution of ventilation. Grimby, Oxhoj and Bake assessed the validity of DB on the distribution of ventilation using inhaled and injected xenon tracers in 6 subdues with COPD (FEV, 24-95% predicted).11 The authors reported an average 68% increase in abdominal wall manner of moving which was not associated with a change in ventilation in any area of the lung These studies confirm earlier findings through Brach et al using inhaled radioactive xenon in similar patients.12

Gosselink et al1 investigated the validity of DB on the work of breathing in patients with relentless COPD (mean FEV^sub 1^ 34% predicted). Patients who were able to increase abdominal motion according to at least two-fold were assessed during resting breathing and during entrance loaded breathing. Although there were no significant changes in tidal turn respiratory frequency, or duty period DB was associated with a decrease in mechanical efficiency, an increase in paradoxical rib cage motions, and a determination for dyspnea to increase.

In summary, a number of studies to date have examined the physiological changes caused from diaphragmatic breathing. None have shown that this is a helpful technique when used with bodily substances with COPD.

Pursed Lips Breathing

During purs lips breathing (PLB) make liables are asked to exhale by the agency of partially closed (pursed) lips. In any cases, patients are told to not use their abdominal muscles during exhalation.5 the same physical therapy text states that PLB may be useful for patients with increased breathing effort because the technique naturally deliberates down breathing, decreases minute ventilation and, in a patients, relieves dyspnea.13 Other authors state that purs lip breathing increases alveolar ventilation and oxygenation and decreases the work of breathing, which should eliminate accessory muscle activity, decrease respiratory rate, increase PaO2, decrease PaCO2, and increase exercise tolerance.5 Another author states that PLB abates the work of breathing at slowing respiratory rate or eliminating accessory muscle activity (especially during exertion), thus increasing the amount of oxygen available to other tissues.14 Interestingly, the same author mentions that the technique is controversial since it has been documented that patients naturally assume a breathing pattern that requires the least activity and delays respiratory muscle fatigue. Another author mentions that patients are likely to maintain PLB and nothing else with conscious effort and will probably recommence their natural breathing pattern when attention is diverted to a task.13

Several investigators have assessed the tenors of PLB in the COPD population. Uniformly they report that the technique decreases respiratory rate,15-19 minute ventilation,18 and PaCO15-17,19 and increases tidal volume15-19 PaO2 1516 and SaO2, 15161820 Intuitively many tribe feel that these beneficial powers are due to positive airway press which prevents premature airway collapse and thus allows more effective ventilation. Ingram and Schilder demonstrated that simulated PLB decreased peak expiratory run in a group of individuals with COPD20 These investigators give an inkling ofed that, according to the Bernoulli principle, this would decrease the transmural squeezing gradient and subsequent airway collapse and account for the positive weights they observed. Muller et al propos this same mechanism was responsible for the changes in respiratory rate and ventilation observ in enslaves with moderately severe COPD.16 Thoman, Stokes, and Ros did not find a difference in ventilation and oxygenation when they compared deliberate deep breathing to PLB in a clump of 21 individuals with COPD19 They hinted that slowing the respiratory rate decreased the dead space, which was responsible for the changes they reported. Spahija and Grassino used expiratory resistive loading to mimic PLB and assessed its purport in healthy individuals.21 They reported that healthy make submissives and those with COPD demonstrated a similar replication to simulated PLB. Premature airway closure was not quick in emergencies in the healthy subjects; therefore Spahija and Grassino, like Thoman and colleagues, proposeed the effects of this technique were not likely to be appropriate to preventing such closure in patient populations.