Danielle S. R. Vieira

Muscle stiffness and strength and their relation to hand function in children with hemiplegic cerebral palsy

This study compared the passive stiffness of wrist flexors and the strength of wrist flexors and extensors in three different wrist positions (30 degrees of flexion, neutral, and 30 degrees of extension) between children with cerebral palsy (CP) and typically developing (TD) comparison children. It also examined associations between these characteristics and manual function in children with CP. Eleven children with spastic hemiplegic CP (six females, five males; mean age 8y 5mo [SD 1y 8mo], range 6-11y) and 11 TD children, matched for age and sex, took part in this study. Passive stiffness of muscles was measured as the torque/angle relation during passive motion. Isometric strength tests were performed and the time needed to complete three tasks based on the Jebsen-Taylor Hand Function Test was recorded. Flexor stiffness was higher in the group with CP. Strength of flexors and extensors in the group with CP was lower with the wrist extended. No difference among test positions was found in the TD group. Moderate correlations were observed between manual function and variables related to strength and stiffness of wrist muscles in the group with CP. Children with CP showed muscle alterations coherent with the use of the wrist in flexion. Intervention on these characteristics could have a positive impact on manual function.

Padrão respiratório e movimento toracoabdominal em indivíduos saudáveis: influência da idade e do sexo

OBJECTIVE: To describe the breathing pattern and thoracoabdominal motion of healthy individuals, taking age and sex into consideration. METHODS: The study included 104 individuals aged 20 to 39, 40 to 59, and 60 to 80 years (41 males and 63 females), with normal body mass index and spirometric values. Participants were evaluated at rest in the supine position, by means of respiratory inductive plethysmography. The following variables were measured: tidal volume (Vt), respiratory frequency (f), minute ventilation (VE), inspiratory duty cycle (Ti/Ttot), mean inspiratory flow (Vt/Ti), rib cage motion (%RC), inspiratory phase relation (PhRIB), expiratory phase relation (PhREB), and phase angle (PhaseAng). Comparisons between the age groups were performed using one-way ANOVA or Kruskal-Wallis H, while comparisons between the sexes were performed using Students t test or the Mann-Whitney U test, depending on the data distribution; p<0.05 was taken to be significant. RESULTS: Comparison between the sexes showed that, in the age groups 20 to 39 and 60 to 80 years, women presented significantly lower values for Vt, VE, and Ti/Ttot than men, and there was no significant difference in the age group 40 to 59 years. Comparisons between the age groups showed that participants aged 60 to 80 presented significantly greater PhRIB and PhaseAng than participants aged 20 to 39 years, without significant differences in the breathing pattern. CONCLUSION: The data suggest that breathing pattern is influenced by sex whereas thoracoabdominal motion is influenced by age.

Chest wall volumes during inspiratory loaded breathing in COPD patients.

Chest wall volumes and breathing patterns of 13 male COPD patients were evaluated at rest and during inspiratory loaded breathing (ILB). The sternocleidomastoid (SMM) and abdominal muscle activity was also evaluated. The main compartment responsible for the tidal volume at rest and during ILB was the abdomen. During ILB patients exhibited, in addition to increases in the ratio of inspiratory time to total time of the respiratory cycle and minute ventilation, increases (p<0.05) in the chest wall tidal volume by an increase in abdomen tidal volume as a result of improvement of end chest wall inspiratory volume without changing on end chest wall expiratory volume. The SMM and abdominal muscle activity increased 63.84% and 1.94% during ILB. Overall, to overcome the load imposed by ILB, COPD patients improve the tidal volume by changing the inspiratory chest wall volume without modifying the predominant mobility of the abdomen at rest and without affecting the end chest wall expiratory volume.

Influence of 4 interfaces in the assessment of maximal respiratory pressures.

BACKGROUND: The measurement of maximal respiratory pressure (MRP) is a procedure widely used in clinical practice to evaluate respiratory muscle strength through the maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax). Its clinical applications include diagnostic procedures and evaluating responses to interventions. However, there is great variability in the equipment and measurement procedures. Understanding the impacts of the characteristics of different interfaces can augment the repeatability of this method and help to establish widely applicable predictive equations. The aim of this study was to evaluate the influence of 4 different interfaces on a subjects capacity to generate MRP and the impact of these interfaces on the repeatability of these measurements. METHODS: Fifty healthy subjects (mean ± SD age 26.36 ± 4.89 y) with normal spirometry were evaluated. MRP was measured by a digital manometer connected to 4 interfaces using different combinations of mouthpieces and tubes. The following variables were analyzed: maximum mean pressure, peak pressure, plateau pressure, and plateau variation. Analysis of variance for repeated measures or a Friedman test was used to compare the 4 interfaces, with P < .008 after Bonferroni adjustment considered significant. RESULTS: There was no significant difference between the 4 interfaces with respect to maximum mean pressure, peak pressure, plateau pressure, or plateau variation for PImax (P ≥ .49) or PEmax (P ≥ .11), nor did the number of tests performed to fulfill the criteria of repeatability for PImax (P = .69) or PEmax (P = .47) differ among the 4 interfaces. CONCLUSIONS: PImax and PEmax values seem not to be influenced by the different interfaces studied, suggesting that patient comfort and availability of interfaces can be considered.

Posição prona e diminuição da assincronia toracoabdominal em recém-nascidos prematuros

OBJECTIVE: To assess the effect of prone and supine positions on breathing pattern variables, thoracoabdominal motion and peripheral oxygen saturation of hemoglobin of premature newborn infants recovering from respiratory distress syndrome, while breathing spontaneously and in rapid eye movement sleep. METHODS: This was a quasi-experimental study. Twelve preterms weighing > 1,000 g at enrollment were studied in both positions, in random order. Respiratory inductive plethysmography was used to analyze breathing pattern (tidal volume, respiratory rate, minute ventilation, mean inspiratory flow) and thoracoabdominal motion (labored breathing index, phase relation in inspiration, phase relation in expiration, phase relation in total breath and phase angle). Pulse oximetry was used to evaluate peripheral oxygen saturation. Students t test for paired samples or the Wilcoxon test were used for statistical analysis. Significance was set at p < 0.05. RESULTS: A total of 9,167 respiratory cycles were analyzed. The prone position was associated with significant reductions in labored breathing index (-0.84±0.69; p = 0.001; 95%CI -1.29 to -0.40), phase relation in inspiration (-27.36±17.55; p = 0.000; 95%CI -38.51 to -16.20), phase relation in expiration (-32.36±16.20; p = 0.000; 95%CI -42.65 to -22.06) and phase relation in total breath (-30.20±14.76; p = 0.000; 95%CI -39.59 to -20.82). There were no significant differences between the two positions in any of the other variables analyzed. CONCLUSION: The prone position resulted in a significant reduction in thoracoabdominal asynchrony, without affecting breathing pattern or peripheral oxygen saturation.

Prone position and reduced thoracoabdominal asynchrony in preterm newborns

OBJECTIVE To assess the effect of prone and supine positions on breathing pattern variables, thoracoabdominal motion and peripheral oxygen saturation of hemoglobin of premature newborn infants recovering from respiratory distress syndrome, while breathing spontaneously and in rapid eye movement sleep. METHODS This was a quasi-experimental study. Twelve preterms weighing > 1,000 g at enrollment were studied in both positions, in random order. Respiratory inductive plethysmography was used to analyze breathing pattern (tidal volume, respiratory rate, minute ventilation, mean inspiratory flow) and thoracoabdominal motion (labored breathing index, phase relation in inspiration, phase relation in expiration, phase relation in total breath and phase angle). Pulse oximetry was used to evaluate peripheral oxygen saturation. Students t test for paired samples or the Wilcoxon test were used for statistical analysis. Significance was set at p < 0.05. RESULTS A total of 9,167 respiratory cycles were analyzed. The prone position was associated with significant reductions in labored breathing index (-0.84+/-0.69; p = 0.001; 95%CI -1.29 to -0.40), phase relation in inspiration (-27.36+/-17.55; p = 0.000; 95%CI -38.51 to -16.20), phase relation in expiration (-32.36+/-16.20; p = 0.000; 95%CI -42.65 to -22.06) and phase relation in total breath (-30.20+/-14.76; p = 0.000; 95%CI -39.59 to -20.82). There were no significant differences between the two positions in any of the other variables analyzed. CONCLUSION The prone position resulted in a significant reduction in thoracoabdominal asynchrony, without affecting breathing pattern or peripheral oxygen saturation.

Reprodutibilidade da determinação do limiar anaeróbico em pacientes com insuficiência cardíaca

BACKGROUND The anaerobic threshold (AT) provides information on functional capacity in heart failure (HF). However, the visual determination of the AT by ventilatory methods is subjective, being susceptible to differences between examiners. OBJECTIVE To evaluate the inter- and intra-examiner reproducibility in the determination of the AT in patients with mild to moderate HF, using visual-graphic and V-slope methods. To compare and correlate the results. METHODS After performing a cardiopulmonary exercise test on a treadmill, visual-graphic and V-slope methods were used for the analysis of the AT. To assess the reproducibility, three examiners determined the AT twice by each method, on different days. For statistical analysis, we used intra-class correlation coefficient (ICC) with p <0.05. RESULTS We evaluated a total of 16 subjects, with a mean age of 45.9 +/- 9.7 years, left ventricle ejection fraction of 20.5 +/- 8.1%, and peak exercise oxygen consumption of 20.6 +/- 7.8 mL/kgmin-1. The intra-examiner reproducibility was high in both methods for the three examiners, with ICC values between 0.87 and 0.99. The inter-examiner reproducibility was moderate in both visual-graphic method (ICC = 0.69) and V-slope method (ICC = 0.64). When comparing methods, the ICC found was 0.91. CONCLUSION AT determination by visual-graphic and V-slope methods showed high and moderate inter- and intra-examiner reproducibility, respectively. Moreover, both methods showed good agreement when compared with each other. These results suggest that both methods can be used in a reproducible way in AT assessment of patients with mild to moderate HF.

Lower-limb endurance training program influences thoracoabdominal motion of patients with COPD?

INTRODUCTION: Thoracoabdominal-TA asynchrony is an important sign of Chronic Obstructive Pulmonary Disease (COPD). Studies investigating the influence of endurance training on TA asynchrony have not been found. OBJECTIVE: To analyze lower-limb endurance training effects on TA asynchrony in patients with COPD. MATERIALS AND METHODS: Two patients with severe COPD were evaluated in a single-subject design AB (A-baseline for six weeks, B-training on cycle ergometer with intensity of 70% of baseline peak load, for 12 weeks) with repeated measures of variables: phase inspiratory relation (PhRIB), phase expiratory relation (PhREB) and phase angle (PhAng). These variables were assessed by respiratory inductive plethysmography during incremental exercise tests on a cycle ergometer (same load and peak load of each test). Statistical methods included visual analysis, two-standard deviation band test and split middle line test, considering significant p < 0.05. It was considered the results for variables with agreement of at least two analyses. Data are presented as mean ± SD for phases A and B. RESULTS: During phase B, Patient 1 presented significant decrease of PhRIB (22.7 ± 3.4 x 17.0 ± 4.9) and PhAng (16.5 ± 5.1 x 13.2 ± 2.1) for same load and PhREB (16.8 ± 3.1 x 13.3 ± 3.1) and PhAng (23.4 ± 1.7 x 20.1 ± 2.3) at peak load. Patient 2 showed significant decrease of PhRIB for same load and (14.4 ± 3.8 x 13.9 ± 3.9) at peak load (19.1 ± 2.5 x 15.7 ± 2.7). CONCLUSIONS: These results suggest that lower-limb endurance training reduced TA asynchrony in patients with severe COPD. The findings may be related, according to the literature, to the lower ventilatory demand and greater exercise capacity of patients with COPD undergoing endurance training.

Functional outcomes in patients with chronic obstructive pulmonary disease: a multivariate analysis

Background Multiple factors can influence the severity of chronic obstructive pulmonary disease (COPD) and the functioning of patients with COPD, such as personal characteristics and systemic manifestations. Objective To evaluate the different factors that can influence the activity and psychosocial impact domains of the Saint Georges Respiratory Questionnaire (SGRQ) in COPD patients. Method Participants, recruited in a university-based hospital, responded to the SGRQ, and in addition, personal, anthropometric, and clinical data were collected. The study was approved by the Institutional Ethics Committee. Data were analyzed using multiple linear regression models, with the SGRQ activity and psychosocial impact scores as outcome variables, and 10 explanatory variables (age, gender, forced expiratory volume in the first second - FEV1, smoking load, body mass index, oxygen therapy, associated diseases, regular physical activity, participation in a formal rehabilitation program, and SGRQ symptoms score) were considered. Results The best regression model for predicting the SGRQ activity score (r2=0.477) included gender, FEV1, and SGRQ symptoms. In contrast, the predictive model with the highest proportion of explained variance in psychosocial impact score (r2=0.426) included the variables gender, oxygen therapy, and SGRQ symptoms. Conclusions The results indicate that the outcomes, while based on functioning parameters in COPD patients, could be partly explained by the personal and clinical factors analyzed, especially by the symptoms assessed by the SGRQ. Thus, it appears that the health conditions of these patients cannot be described by isolated variables, including pulmonary function parameters.