Desiderio Cano Porras

Effect of Volume-Oriented Versus Flow-Oriented Incentive Spirometry on Chest Wall Volumes, Inspiratory Muscle Activity, and Thoracoabdominal Synchrony in the Elderly

BACKGROUND: Aging causes physiological and functional changes that impair pulmonary function. Incentive spirometry is widely used for lung expansion, but the effects of volume-oriented incentive spirometry (VIS) versus flow-oriented incentive spirometry (FIS) on chest wall volumes, inspiratory muscle activity, and thoracoabdominal synchrony in the elderly are poorly understood. We compared VIS and FIS in elderly subjects and healthy adult subjects. METHODS: Sixteen elderly subjects (9 women, mean ± SD age 70.6 ± 3.9 y, mean ± SD body mass index 23.8 ± 2.5 kg/m2) and 16 healthy adults (8 women, mean ± age 25.9 ± 4.3 y, mean ± body mass index 23.6 ± 2.4 kg/m2) performed quiet breathing, VIS, and FIS in randomized sequence. Chest wall kinematics (via optoelectronic plethysmography) and inspiratory muscle activity (via surface electromyography) were assessed simultaneously. Synchrony between the superior thorax and abdominal motion was calculated (phase angle). RESULTS: In the elderly subjects both types of incentive spirometry increased chest wall volumes similarly, whereas in the healthy adult subjects VIS increased the chest wall volume more than did FIS. FIS and VIS triggered similar lower thoracoabdominal synchrony in the elderly subjects, whereas in the healthy adults FIS induced lower synchrony than did VIS. FIS required more muscle activity in the elderly subjects to create an increase in chest wall volume. CONCLUSIONS: Incentive spirometry performance is influenced by age, and the differences between elderly and healthy adults response should be considered in clinical practice.

Volume Rather Than Flow Incentive Spirometry Is Effective in Improving Chest Wall Expansion and Abdominal Displacement Using Optoelectronic Plethysmography

BACKGROUND: Incentive spirometers are widely used in clinical practice and classified as flow-oriented (FIS) and volume-oriented (VIS). Until recently the respiratory inductive plethysmography used to evaluate the effects of incentive spirometry on chest wall mechanics presented limitations, which may explain why the impact of VIS and FIS remains poorly known. OBJECTIVE: To compare the effects of VIS and FIS on thoracoabdominal mechanics and respiratory muscle activity in healthy volunteers. METHODS: This cross-sectional trial assessed 20 subjects (12 female, ages 20–40 years, body mass index 20–30 kg/m2). All subjects performed 8 quiet breaths and 8 deep breaths with FIS and VIS, in a randomized order. We measured thoracoabdominal chest wall, upper and lower rib-cage, and abdominal volumes with optoelectronic plethysmography, and the muscle activity of the sternocleidomastoid and superior and inferior intercostal muscles with electromyography. RESULTS: VIS increased chest wall volume more than did FIS (P = .007) and induced a larger increase in the upper and lower rib-cages and abdomen (156%, 91%, and 151%, respectively, P < .001). By contrast, FIS induced more activity in the accessory muscles of respiration than did VIS (P < .001). CONCLUSIONS: VIS promotes a greater increase in chest wall volume, with a larger abdominal contribution and lower respiratory muscle activity, than does FIS in healthy adults.

Dynamic hyperinflation and exercise limitations in obese asthmatic women

Obese individuals and patients with asthma can develop dynamic hyperinflation (DH) during exercise; however, no previous study has investigated DH as a factor associated with reduced exercise capacity in obese asthmatic women. The aim of the present study was to examine the occurrence of DH and exercise limitations in obese asthmatics. Obese grade II [obese group (Ob-G); BMI 35-39.9 kg/m2; n=36] and nonobese [nonobese group (NOb-G); BMI 18.5-29.9 kg/m2; n=18] asthmatic patients performed a cardiopulmonary test to quantify peak V̇o2 and a submaximal exercise test to assess DH. Anthropometric measurements, quadriceps endurance, and lung function were also evaluated. A forward stepwise regression was used to evaluate the association between exercise tolerance (wattage) and limiting exercise factors. Fifty-four patients completed the protocol. The Ob-G (n = 36) presented higher peak V̇o2 values but lower power-to-weight ratio values than the NOb-G (P <0 .05). DH was more common in the Ob-G (72.2%) than in the NOb-G (38.9%, P < 0.05). The Ob-G had a greater reduction in the inspiratory capacity (-18 vs. -4.6%, P < 0.05). Exercise tolerance was associated with quadriceps endurance (r = 0.65; p<0.001), oxygen pulse (r = 0.52; p=0.001), and DH (r = -0.46, P = 0.005). The multiple regression analysis showed that the exercise tolerance could be predicted from a linear association only for muscular endurance (r = 0.82 and r2 = 0.67). This study shows that dynamic hyperinflation is a common condition in obese asthmatics; they have reduced fitness for activities of daily living compared to nonobese asthmatics. However, peripheral limitation was the main factor associated with reduced capacity of exercise in these patients.NEW & NOTEWORTHY This is the first study to investigate the occurrence of dynamic hyperinflation (DH) in obese asthmatics. Our results demonstrate that obese asthmatics present a higher frequency and intensity of DH than nonobese asthmatics. We also show that physical deconditioning in this population is linearly associated with cardiac (O2 pulse), respiratory (DH), and peripheral muscle (resistance) limitation. However, multiple linear regression demonstrated that peripheral muscle limitation may explain the exercise limitation in this population.

Effects of aerobic training combined with respiratory muscle stretching on the functional exercise capacity and thoracoabdominal kinematics in patients with COPD: a randomized and controlled trial

Background Patients with COPD present a major recruitment of the inspiratory muscles, predisposing to chest incoordination, increasing the degree of dyspnea and impairing their exercise capacity. Stretching techniques could decrease the respiratory muscle activity and improve their contractile capacity; however, the systemic effects of stretching remain unknown. Objective The aim of this study was to evaluate the effects of aerobic training combined with respiratory muscle stretching on functional exercise capacity and thoracoabdominal kinematics in patients with COPD. Design This study was a randomized and controlled trial. Participants A total of 30 patients were allocated to a treatment group (TG) or a control group (CG; n=15, each group). Intervention The TG was engaged in respiratory muscle stretching and the CG in upper and lower limb muscle stretching. Both groups performed 24 sessions (twice a week, 12 weeks) of aerobic training. Evaluations Functional exercise capacity (6-minute walk test), thoracoabdominal kinematics (optoelectronic plethysmography), and respiratory muscle activity (surface electromyography) were evaluated during exercise. Analysis of covariance was used to compare the groups at a significance level of 5%. Results After the intervention, the TG showed improved abdominal (ABD) contribution, compartmental volume, mobility, and functional exercise capacity with decreased dyspnea when compared with the CG (P<0.01). The TG also showed a decreased respiratory muscle effort required to obtain the same pulmonary volume compared to the CG (P<0.001). Conclusion Our results suggest that aerobic training combined with respiratory muscle stretching increases the functional exercise capacity with decreased dyspnea in patients with COPD. These effects are associated with an increased efficacy of the respiratory muscles and participation of the ABD compartment.

Relationship Between Knee Extensors Power Output and Vastus Lateralis EMG Activation in Elderly Women: Influence of Mother Wavelet Selection

RESEARCH ARTICLE Relationship Between Knee Extensors Power Output and Vastus Lateralis EMG Activation in Elderly Women: Influence of Mother Wavelet Selection João Pedro Pinho, Bruno Mezêncio, Desidério Cano Porras, Julio Cerca Serrão and Alberto Carlos Amadio Laboratory of Biomechanics, University of São Paulo, São Paulo, Brazil Department of Physical Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil

Thoracoabdominal asynchrony: Two methods in healthy, COPD, and interstitial lung disease patients

Background Thoracoabdominal asynchrony is the nonparallel motion of the ribcage and abdomen. It is estimated by using respiratory inductive plethysmography and, recently, using optoelectronic plethysmography; however the agreement of measurements between these 2 techniques is unknown. Therefore, the present study compared respiratory inductive plethysmography with optoelectronic plethysmography for measuring thoracoabdominal asynchrony to see if the measurements were similar or different. Methods 27 individuals (9 healthy subjects, 9 patients with interstitial lung disease, and 9 with chronic obstructive pulmonary disease performed 2 cycle ergometer tests with respiratory inductive plethysmography or optoelectronic plethysmography in a random order. Thoracoabdominal asynchrony was evaluated at rest, and at 50% and 75% of maximal workload between the superior ribcage and abdomen using a phase angle. Results Thoracoabdominal asynchrony values were very similar in both approaches not only at rest but also with exercise, with no statistical difference. There was a good correlation between the methods and the Phase angle values were within the limits of agreement in the Bland-Altman analysis. Conclusion Thoracoabdominal asynchrony measured by optoelectronic plethysmography and respiratory inductive plethysmography results in similar values and has a satisfactory agreement at rest and even for different exercise intensities in these groups.

Comparison between the phase angle and phase shift parameters to assess thoracoabdominal asynchrony in COPD patients

Determining the presence of thoracoabdominal asynchrony in chronic obstructive pulmonary disease (COPD) patients is clinically relevant, but there is no consensus on the optimal parameters for performing this analysis. We assessed 22 COPD patients (FEV1 40 ± 10% predicted) and 13 healthy controls during rest and exercise with optoelectronic plethysmography (70% maximum workload) on a cycle ergometer. Thoracoabdominal asynchrony was calculated by using phase angle and phase shift parameters following a three-compartment model involving the upper and lower rib cages and abdomen. Patients were classified as having thoracoabdominal asynchrony (TAA+) or not (TAA-) based on control values (mean ± 2 SDs). The chest wall volume and compartmental contribution were also measured. Thoracoabdominal asynchrony was observed in the lower rib cage. The phase angle detected more TAA+ patients at rest (15 vs. 7 patients) and during exercise (14 vs. 8 patients) compared with the phase shift. TAA+ patients also presented a lower chest wall volume, lower rib cage contribution, and higher abdominal contribution to chest wall volume compared with the control and TAA- patients. Thoracoabdominal asynchrony was more detectable during rest and exercise using the phase angle parameter, and it was observed in the lower rib cage compartment, reducing the chest wall volume during exercise in patients with COPD.NEW & NOTEWORTHY This study contributes to advance the knowledge over the previous lack of consensus on the assessment of thoracoabdominal asynchrony. We rigorously evaluated the related features that interfere in the measurement of the asynchrony (measurement tool, chest wall model and calculation parameter). Our results suggest that phase angle detects more suitably thoracoabdominal asynchrony that occurs on the lower ribcage and leads to a reduction in the chest wall volume during exercise in COPD patients.