Measurement Of Respiratory Muscle Strength Research Articles

Assessing the Consequences of Smoking Tobacco Products with Consideration of the Forced Oscillation Technique.

BACKGROUND The effects of cigarette smoking on the health of active smokers and passive smokers have long been known, in contrast to the effects of alternative forms of nicotine intake that are gaining popularity. The aim of the study was to assess the effects of smoking traditional cigarettes and alternative forms of nicotine intake on the functional state of the respiratory system of smokers and non-smokers. MATERIAL AND METHODS Study participants (n=60) were divided into 3 groups: non-smokers (control group), cigarette smokers, and nicotine alternative users. Respiratory function testing (spirometry), forced oscillation technique, and measurement of respiratory muscle strength (PImax, PEmax) were performed. All of the above respiratory function tests were performed in accordance with European Respiratory Society and American Thoracic Society recommendations. RESULTS Smokers and those using alternative forms of nicotine intake had significantly higher values, including resistance at 5 Hz% and 11 Hz%, among others. CONCLUSIONS Smokers and users of alternative forms of nicotine are characterized by reduced flow through the small bronchioles, as evidenced by a reduction in maximal expiratory flow at 25% of vital capacity. Smokers and users of alternative forms of nicotine have higher resistance values at the height of small and medium bronchioles. Assessment method of technical forced oscillation parameters is simple to perform to detect early airway changes and is an important element in the early diagnosis of changes in smokers. The correlation analysis showed a significant correlation between age of smoking initiation/use of alternative forms of nicotine and changes in mid bronchial resistance.

The influence of low resistance respiratory muscle training on pulmonary function and high intensity exercise performance

Background/objectivesRespiratory muscle training (RMT) was recognized as an effective means to improve respiratory muscle (RM) strength and enhance exercise performance. The purpose of this study was to examine the effect of low-intensity RMT on RM strength, pulmonary function, and performance. MethodsFourteen healthy active adults were assigned randomly to either a training or placebo group. The training group completed six weeks of RMT, which consisted of a first week, 1 set of 15 min/d, 5 d/wk at 10–25% of maximal inspiratory pressure (PImax), and the remaining 5 weeks, 2 sets of 15 min/d, 5 d/wk, at 30% PImax. The placebo group followed the same protocol but with almost no additional ventilatory resistance. Measurement of RM strength and endurance, spirometry, and endurance exercise performance were obtained before and after the RMT program. ResultsIn the training group, PImax (+14%) and maximal expiratory pressure (PEmax, +27%), forced vital capacity (FVC, +3.6%), maximal oxygen uptake (VO2max, +11%), and time to exhaustion (Tlim90%, +25%) increased significantly from baseline values (P < 0.05). No significant changes were observed in the placebo group. Also, no significant interaction in maximum voluntary ventilation (MVV12), minute ventilation (VE), and respiratory rate (RR) were detected. ConclusionsThese data suggest that low-intensity RMT is an effective tool to improve RM strength, pulmonary elastic properties and endurance exercise performance.

Reliability and validity of low cost pressure gauge manometer for measurement of respiratory muscle strength in healthy children: a cross-sectional study

Background: Assessing respiratory muscle strength is an important aspect for clinical practice as well as in research. Multiple factors such as health status of an individual, level of physical fitness and postsurgical recovery of an individual have an influence on respiratory biomechanics. Respiratory muscle strength is determined by measuring maximal inspiratory pressure and maximal expiratory pressure. There is a need for a cost effective, portable, easy to build device specifically to estimate respiratory muscle strength. There is insufficient literature regarding the resources used to determine the respiratory muscle strength testing in children, hence this study aims to establish the reliability and validity of low cost pressure gauge manometer which could be a useful tool in measuring respiratory muscle strength in children. Methods: A capsule sensing pressure gauge constructed according to the American thoracic society guidelines with a calibration of pressure between −200 cmH2O to +200 cmH2O. It was used to measure the respiratory muscle strength. The study was conducted on 300 healthy children. Results: SPSS software was used for statistical analysis. Reliability of 0.92 and 0.97 was obtained for MIP and MEP respectively by test retest method. Construct validity index showed a validity score of 0.8 for MIP and MEP. Conclusions: The results indicate that the low cost pressure gauge manometer can be used as a reliable and valid device to measure respiratory muscle strength in children.

Association of Diaphragm Thickness and Respiratory Muscle Strength With Indices of Sarcopenia.

To evaluate the relationship between respiratory muscle strength, diaphragm thickness (DT), and indices of sarcopenia. This study included 45 healthy elderly volunteers (21 male and 24 female) aged 65 years or older. Sarcopenia indices, including hand grip strength (HGS) and body mass index-adjusted appendicular skeletal muscle (ASM/BMI), were measured using a hand grip dynamometer and bioimpedance analysis, respectively. Calf circumference (CC) and gait speed were also measured. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were obtained using a spirometer, as a measure of respiratory muscle strength. DT was evaluated through ultrasonography. The association between indices of sarcopenia, respiratory muscle strength, and DT was evaluated using Spearman's rank correlation test, and univariate and multiple regression analysis. ASM/BMI (r=0.609, p<0.01), CC (r=0.499, p<0.01), HGS (r=0.759, p<0.01), and gait speed (r=0.319, p<0.05) were significantly correlated with DT. In the univariate linear regression analysis, MIP was significantly associated with age (p=0.003), DT (p<0.001), HGS (p=0.002), CC (p=0.013), and gait speed (p=0.026). MEP was significantly associated with sex (p=0.001), BMI (p=0.033), ASM/BMI (p=0.003), DT (p<0.001), HGS (p<0.001), CC (p=0.001) and gait speed (p=0.004). In the multiple linear regression analysis, age (p=0.001), DT (p<0.001), and ASM/BMI (p=0.008) showed significant association with MIP. DT (p<0.001) and gait speed (p=0.050) were associated with MEP. Our findings suggest that respiratory muscle strength is associated with DT and indices of sarcopenia. Further prospective studies with larger sample sizes are needed to confirm these findings.

Effect of Swimming Exercise on Respiratory Muscle Strength and Respiratory Functions in Children with Autism.

The aim of this study is to examine the effects of swimming exercise on respiratory muscle strength and respiratory functions in children with autism. Autism is a mental disorder that affects many areas such as sensory, cognitive, motor, and psycho-motor development in individuals. For this purpose, 15 individuals with autism, 8 of which were in the experimental group and 7 in the control group, participated in the study. The experimental group was subjected to swimming exercise for 1 hour, 3 days a week, for 6 weeks. The control group was not included in this exercise. Respiratory muscle strength and pulmonary function tests were applied to both groups before and after the 6-week period. The obtained data were analyzed using Statistical Package for Social Sciences Program Version 22.0. Values were presented as minimum, maximum, mean, standard deviation, and standard error. The Shapiro-Wilk test was used to test for normality. Paired-sample t-test was used for pre-test and post-test, and independent-sample t-test was used for intergroup analysis. At the end of 6 weeks, according to the statistical analysis data, there was a significant difference in some of the respiratory function parameters of the experimental group (P < .05), and an improvement was observed in the respiratory muscle strength values, but no significant difference was found (P > .05). No significant difference was found in the respiratory functions of the control group as a result of respiratory muscle strength measurements (P > .05). As a result, we can say that swimming exercise is effective in improving respiratory muscle strength and respiratory functions in children with autism.

Peak oxygen uptake and respiratory muscle performance in patients with chronic obstructive pulmonary disease: Clinical findings and implications.

The maximal oxygen uptake (VO2max) is the gold standard measure of aerobic exercise capacity and is an important outcome measure in patients with chronic obstructive pulmonary disease (COPD). And respiratory muscle performance is also an important functional parameter for COPD patients. In addition to the traditional respiratory muscle strength test, the Test of Incremental Respiratory Endurance has recently been introduced and validated in patients with COPD. However, the relationship between VO2 and respiratory muscle performance in COPD is not well understood. Therefore, this study investigated the correlations among VO2 and respiratory muscle performance and other functional markers in COPD. A total of 32 patients with COPD were enrolled. All study participants underwent the following assessments: cardiopulmonary exercise test, pulmonary function test, respiratory muscle strength test, peripheral muscle strength test, and bioelectrical impedance analysis. When comparing VO2peak and respiratory muscle parameters, the sustained maximal inspiratory pressure (SMIP) was the only factor with a significant relationship with VO2peak. Among other functional parameters, the forced expiratory volume in one second (FEV1) showed the strongest correlation with VO2peak. It was followed by phase angle values of lower limbs, leg extension peak torque, age, and total skeletal muscle mass. When comparing respiratory muscle performance with other functional parameters, the SMIP showed the strongest correlation with hand grip strength, followed by peak cough flow, forced vital capacity, maximal inspiratory pressure, and FEV1. The results showed that the SMIP was more significantly correlated with VO2peak than the static measurement of respiratory muscle strength. This suggests that TIRE may be a useful assessment tool for patients with COPD. Additionally, FEV1 and other functional markers were significantly correlated with VO2peak, suggesting that various parameters may be used to evaluate aerobic power indirectly.

Executive Summary: International Clinical Practice Guidelines for Pediatric Ventilator Liberation, A PALISI Network Document.

Pediatric specific ventilator liberation guidelines are lacking despite the many studies exploring elements of extubation readiness testing. The lack of clinical practice guidelines has led to significant and unnecessary variation in methods used to assess pediatric patients' readiness for extubation. Twenty-six international experts comprised a multi-professional panel to establish pediatric specific ventilator liberation clinical practice guidelines, focusing on acutely hospitalized children receiving invasive mechanical ventilation for more than 24 hours. Eleven key questions were identified and first prioritized using the Modified Convergence of Opinion on Recommendations and Evidence. Systematic review was conducted for questions which did not meet an a-priori threshold of ≥80% agreement, with Grading of Recommendations, Assessment, Development, and Evaluation methodologies applied to develop the guidelines. The panel evaluated the evidence, drafted, and voted on the recommendations. Three questions related to systematic screening, using an extubation readiness testing bundle and use of a spontaneous breathing trial as part of the bundle met Modified Convergence of Opinion on Recommendations criteria of ≥80% agreement. For the remaining 8 questions, 5 systematic reviews yielded 12 recommendations related to the methods and duration of spontaneous breathing trials; measures of respiratory muscle strength; assessment of risk of post-extubation upper airway obstruction and its prevention; use of post-extubation non-invasive respiratory support; and sedation. Most recommendations were conditional and based on low to very low certainty of evidence. This clinical practice guideline provides a conceptual framework with evidence-based recommendations for best practices related to pediatric ventilator liberation. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Home-Based Long-Term Physical Endurance and Inspiratory Muscle Training for Children and Adults With Fontan Circulation-Initial Results From a Prospective Study.

BackgroundPatients with congenital heart disease (CHD)—including those after Fontan operation—are encouraged to be physically active.AimTo prospectively determine the effects of an individually adapted, home-based cycle ergometer endurance training in combination with inspiratory muscle training (IMT) in pediatric and adult Fontan patients. We, herein, report the results of the initial 10-months follow-up (phase 1).Methods18 patients (median age 16.5 years; range 10-43 years) completed baseline check-ups, and 4 and 10 months follow-up visits, which each included cardiopulmonary exercise testing (CPET), bodyplethysmography (including measurement of respiratory muscle strength), and a quality of life questionnaire (PedsQL™). The training program consisted of a home-based cycle ergometer endurance training on a “Magbike® AM-5i/3i” (DKN Technology®, Clermont-Ferrand, France) and IMT with a handheld “POWERbreathe® Medic plus” device. Patients performed 90 min of endurance training per week in addition to IMT (30 breaths per day, 6-7 times per week). After the first 4 months, patients underwent additional interval training.ResultsAfter 10 months of training, we observed significant increases in maximum relative workload (W/kg, p = 0.003) and in maximum inspiratory (MIP, p = 0.002) and expiratory (MEP, p = 0.008) pressures. Peak VO2 values did not increase significantly as compared to baseline (p = 0.12) in the entire cohort (n = 18), but reached statistical significance in a subgroup analysis of teenage/adult patients (n = 14; p = 0.03). Patients' subjective quality of life did not show any significant changes after 10 months of training.DiscussionIn Fontan patients, an individually adapted home-based training is safe and associated with improvements in some CPET variables. However, these improvements did not translate into an improved QoL after 10 months. With an unclear, but most likely negative, impact of the COVID-19 pandemic, improvements in QoL may become evident during further follow-up (phase 2 of the study).

Effects of Respiratory Muscle Training (RMT) on Ventilatory Parameters and Respiratory Muscle Strength (RMS) in Different Postures of the Rowing Stroke in Elite Rowers of Sri Lanka

Background: Rowing places ‘extreme’ demands on ventilation due to the cramped body posture during the rowing stroke. The aim of this study was to investigate the effects of a 12-week respiratory muscle training (RMT) program on ventilatory parameters and respiratory muscle strength (RMS) in different postures of the rowing stroke in professional male rowers in Sri Lanka. Methods: Twenty national male rowers, aged 20-35 years were grouped randomly into an experimental (n=11) and a control (n=9) group. Prior to the study, baseline measurements of ventilatory functions (spirometry) and RMS were assessed by a portable spirometer and hand held mouth pressure meter respectively. Subsequently, rowers in the experimental group were prescribed a RMT program comprising of breathing and abdominal exercises while control group was prescribed a general exercise program for 12 weeks after which all the above parameters were assessed again.Conclusion: Ventilatory functions and RMS were not statistically significant amongst the different rowing postures (p&gt;0.05). Ventilatory functions were observed to be significantly higher in the experimental group than the control group following the respective training programs (p&lt;0.05). The novel RMT program had a beneficial effect in improving the ventilatory functions in the experimental group in the different postures of the rowing stroke.

Assessment of Lumbar Extensor Muscles in the Context of Trunk Function, a Pilot Study in Healthy Individuals

A comprehensive assessment of trunk function, including the lumbar extensor muscles, appears to be important in various conditions affecting axial musculature. This pilot cross-sectional observational study aimed to define a battery of tests that comprehensively assess trunk muscle function (strength and muscular endurance). Sixty subjects without low back pain (LBP) underwent measurement of isometric lower back extensor strength using a hand-held dynamometer (HHD) in three positions; measurement of respiratory muscle strength; and Biering-Sørensen, prone-plank, and side-bridge tests. The repeatability, short-term and long-term reliability using the HHD device in different postural positions was confirmed. The greatest isometric lower back extensor strength was generated in the sitting position by male subjects. Time of effort in the Biering-Sørensen test was longer in women and older subgroups than in men and younger individuals, although this was not the case for the other two muscular endurance tests. This pilot monitoring of trunk muscle strength and endurance in healthy volunteers may lead to a better understanding of trunk muscle function. Based on this methodological background, the authors aim to use the defined battery of tests in their further studies in a group of patients with LBP and certain neuromuscular diseases to verify its usefulness in clinical practice.

Respiratory muscle weakness and its association with exercise capacity in patients with chronic obstructive pulmonary disease.

IntroductionAlthough COPD patients commonly present respiratory complaints despite pharmacological treatment, dyspnea does not correlate directly and linearly with spirometric data, a fact that makes it difficult to select patients for pulmonary rehabilitation. Thus, seems logical that the measurement of respiratory muscle strength could help in this initial assessment if it presents a good correlation with exercise capacity. The aim of this study is to assess whether patients with muscle weakness, characterized as a reduction in maximal inspiratory pressure (PImax) below 70% of predicted value, have a good relationship between the assessed respiratory muscle strength and the exercise capacity measured by the 6‐min walk test (6MWT) in patients with COPD.MethodsPatients diagnosed with COPD according to the 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) on regular use of their medications, without exacerbations for 3 months or more and with respiratory muscle weakness (PImax < 70% of predicted) performed 6MWT in a 30‐m‐long flat corridor.ResultsData from 81 patients were analyzed. There was a strong correlation between the distance of the 6MWD with the PImax (r = 0.764, p < 0.0001). When separating the sample by the 350‐m cut in the 6MWD, we found that the patients with the worst performance in the test are those who present the greatest respiratory muscle weakness.ConclusionPImax correlates well with exercise capacity, and patients with respiratory muscle weakness could be referred to a pulmonary rehabilitation protocol tied to inspiratory muscle training.

Characterization of sleep-disordered breathing in children with Duchenne muscular dystrophy by the American Academy of Sleep Medicine criteria vs disease-specific criteria: what are the differences?

Individuals with Duchenne muscular dystrophy (DMD) frequently develop sleep-disordered breathing. Noninvasive ventilation is often prescribed for sleep-disordered breathing treatment based on the American Academy of Sleep Medicine (AASM) criteria. In 2018, DMD disease-specific criteria for sleep-disordered breathing were established. Our study aimed to examine the clinical interpretation differences using these different criteria. We performed a multicenter, retrospective chart review of children with DMD followed at The Hospital for Sick Children, Toronto, Canada, and Rady Children's Hospital, San Diego, California, who underwent polysomnography from August 1, 2012, to February 29, 2020. Baseline characteristics and polysomnography data were summarized using descriptive statistics. Agreement for the diagnosis of sleep-disordered breathing evaluated by kappa statistics and sensitivity/specificity analysis was assessed. One hundred five male children with DMD (mean ± SD age: 12.1 ± 3.8 years; body mass index z score: 0.2 ± 2.3) were included. The proportions of children with DMD that met at least 1 AASM criterion and at least 1 DMD criterion were 45.7% and 67.6%, respectively. We found that 32.4% of children met neither AASM nor DMD criteria. Overall agreement between AASM and DMD criteria was moderate (k = 0.57). There was almost perfect agreement in sleep apnea diagnosis (k = 0.90); however, there was only slight agreement in hypoventilation diagnosis (k = 0.12) between AASM and DMD criteria. There were more children with DMD diagnosed with nocturnal hypoventilation and prescribed noninvasive ventilation using DMD criteria compared with AASM criteria. Future studies should address whether the prescription of noninvasive ventilation for children with DMD based on both criteria is associated with different clinical outcomes. Hurvitz MS, Sunkonkit K, Massicotte C, Li R, Bhattacharjee R, Amin R. Characterization of sleep-disordered breathing in children with Duchenne muscular dystrophy by the American Academy of Sleep Medicine criteria vs disease-specific criteria: what are the differences? J Clin Sleep Med. 2022;18(2):609-615.

Effectiveness and safety of a simple home-based rehabilitation program in pulmonary arterial hypertension: an interventional pilot study

BackgroundRehabilitation plays an important role in the management of patients with pulmonary arterial hypertension (PAH) and current guidelines recommend implementation of a monitored individualized exercise training program as adjuvant therapy for stable PAH patients on optimal medical treatment. An optimal rehabilitation model for this group of patients has not yet been established. This randomized prospective study assessed the effectiveness and safety of a 6-month home-based caregiver-supervised rehabilitation program among patients with pulmonary arterial hypertension.MethodsA total of 39 patients with PAH were divided into two groups: intervention group (16 patients), subjected to a 6-month home-based physical training and respiratory rehabilitation program adapted to the clinical status of participants, and control group (23 patients) who did not perform physical training. The 6-min walk test (6MWT), measurement of respiratory muscle strength, quality of life assessment (SF-36, Fatigue Severity Scale – FSS) were performed before study commencement, and after 6 and 12 months. Adherence to exercise protocol and occurrence of adverse events were also assessed.ResultsPhysical training significantly improved 6MWT distance (by 71.38 ± 83.4 m after 6 months (p = 0.004), which remained increased after 12 months (p = 0.043), and respiratory muscle strength after 6 and 12 months (p < 0.01). Significant improvement in quality of life was observed after the training period with the use of the SF-36 questionnaire (Physical Functioning, p < 0.001; Role Physical, p = 0.015; Vitality, p = 0.022; Role Emotional, p = 0.029; Physical Component Summary, p = 0.005), but it did not persist after study completion. Adherence to exercise protocol was on average 91.88 ± 14.1%. No serious adverse events were noted.ConclusionAccording to study results, the home-based rehabilitation program dedicated to PAH patients is safe and effective. It improves functional parameters and quality of life. Strength of respiratory muscles and 6MWD remain increased 6 months after training cessation.Trial registrationClinicalTrials.gov, NCT03780803. Registered 12 December 2018

Impact of two different pulmonary rehabilitation methods in children with down syndrome

PurposeTo investigate and compare the effect of proprioceptive neuromuscular facilitation of respiratory muscles with that of inspiratory muscle training as a preventive measure on respiratory muscle strength, chest expansion, spirometry, and functional capacity in children with Down syndrome. MethodsForty-five Down syndrome participants with an age ranged from 10 to 13 years were enrolled. There were distributed into three groups. The study group A (n = 15) underwent proprioceptive neuromuscular facilitation of respiratory muscles while study group B (n = 15) underwent inspiratory muscle training. Third group C (n = 15) was a control group. The three groups received aerobic exercises using the bicycle ergometer for 20 min, 5 times/week for 12 successive weeks. The treatment program for both study groups was conducted for 20–30 min, 5 times/week for 12 successive weeks. Measurements of respiratory muscle strength (MIP, MEP), chest expansion, spirometry test (VC, FEV1, PEFR, MVV) and 6 min walk test were measured pre and post treatment. ResultsThe post treatment mean values of all investigated variables were significantly increased in both study groups with higher effect to group underwent proprioceptive neuromuscular facilitation of respiratory muscles. ConclusionBoth proprioceptive neuromuscular facilitation of respiratory muscles and inspiratory muscle training are effective in children with Down syndrome on improving respiratory muscle strength, chest expansion, spirometry and functional capacity with superior effect of proprioceptive neuromuscular facilitation.

Agreement and reliability of repeated bedside respiratory muscle strength measurements in acute and subacute stroke.

Many stroke trials include maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) outcome measurements. However, data on agreement and reliability of repeated MIP, MEP, and SNIP measurements in acute and subacute stroke patients are scarce. This study employed a test-retest design. Eighteen patients (seven female) with mean (SD) age 59 (14.5) years were recruited from neurological wards. Median (range) time since first stroke was 50.5 (21-128) days. MIP, MEP, and SNIP were measured repeatedly in three testing sessions (S1-3) conducted within 24h and following international standards. Intra-rater agreement between testing sessions was analyzed using the Bland-Altman method. Test-retest reliability was analyzed using intra-class correlation coefficient (ICC). Association between individual measurement variability, time poststroke, and level of stroke impairment was analyzed using Spearman's rho. Mean difference and 95% limits of agreement for MIP were -0.40 (-23.02, 22.22) cmH2 O between S1 and S2, and 2.14 (-12.79, 16.99) cmH2 O between S2 and S3; for MEP, -4.56 (-29.01, 19.90) cmH2 O between S1 and S2, and 0.29 (-24.28, 24.87) cmH2 O between S2 and S3; and for SNIP, -10.56 (-38.48, 17.37) cmH2 O between S1 and S2, and -6.06 (-27.32, 15.20) cmH2 O between S2 and S3. ICCs for MIP, MEP, and SNIP were ≥0.9 throughout. There were no strong correlations between individual measurement variability and time poststroke or level of stroke impairment. MIP, MEP, and SNIP in acute and subacute stroke patients show good test-retest reliability for group averages; however, absolute agreement can vary considerably for some individuals.

Predictors of functional capacity as measured by the Glittre activities of daily living test in women with rheumatoid arthritis.

Although pulmonary involvement is the most common extra-articular manifestation of rheumatoid arthritis (RA), traditional pulmonary function tests (PFTs) do not show a good correlation with the field tests usually performed in these patients. In recent decades, measurement of ventilation distribution heterogeneity through the nitrogen single-breath washout (N2SBW) test and evaluation of functional capacity during exercise using the Glittre activities of daily living test (GA-T) have been increasingly used. Therefore, the objective of this study was to evaluate predictors of GA-T outcomes in women with RA considering demographic, anthropometric, clinical, functional variables, and chest computed tomography (CT) findings. Forty-three women with RA underwent the GA-T, the N2SBW test, spirometry, measurement of the diffusing capacity for carbon monoxide (DLco), measurement of respiratory muscle strength, and evaluation of physical function of the lower and upper limbs through the Health Assessment Questionnaire Disability Index (HAQ-DI). Chest CT scans were analyzed retrospectively. The GA-T time showed significant correlations with the DLco (rs=-0.397, P=0.008), forced vital capacity/DLco (rs=0.307, P=0.044), phase III slope of the N2SBW test (SIIIN2, rs=0.644, P<0.0001), and the HAQ-DI (rs=0.482, P=0.001). Disease extent as assessed by chest CT was associated with the GA-T time. On multiple regression analysis, the SIIIN2 and HAQ-DI were the only predictors of the GA-T time, explaining 40% of its variability. Thus, ventilation distribution heterogeneity and worse physical function substantially explain the variability in GA-T time in women with RA and varying extents of disease on chest CT.

Fuerza muscular respiratoria y movilidad torácica en niños sanos. Relación con medidas antropométricas

IntroductionThe measurement of respiratory muscle strength and thoracic mobility are important in clinical assessment of the respiratory system in the paediatric population, however, their values can change according to the characteristics of the population of each country. The objective of the study was to describe respiratory muscle strength and thoracic mobility in healthy children from Cali, Colombia, and analyse their correlation with anthropometric measurements. Materials and MethodsA cross-sectional study. We included healthy children between 8 and 11 years old, from a school in Cali, Colombia, whose respiratory muscle strength was measured with Maximum Inspiratory Pressure (MIP) and Maximum Expiratory Pressure (MEP) and thoracic mobility with axillary and xiphoid cirtometry. Anthropometric measurements were taken, such as weight, height and BMI-for-age. Results89 children were admitted, most were female (50.6%) and with normal BMI-for-age (62.9%). Median MIP -60.0 cmH2O (IQR 44.0) and MEP 49.0 cmH2O (IQR 19.0). Median axillary cirtometry 4.5 cm (IQR 1.6) and xiphoid cirtometry 4.7 cm (IQR 1.7). MIP correlated with BMI-for-age (rs = 0.23 p = 0.030), axillary cirtometry with weight (rs = 0.35 p = 0.001) and BMI-for-age (rs = 0.31 p = 0.003), xiphoid cirtometry with weight (rs = 0.24 p = 0.027) and height (rs = 0.22 p = 0.037). There was no correlation between MIP-MEP and cirtometry. DiscussionRespiratory muscle strength and thoracic mobility depend on changes in the growth of the infant and differential characteristics between boys and girls during puberty.

Measurement of maximal respiratory static pressure in stable COPD patients and their co-rrelation with various physiological anthropometric and spirometry parpmeters and arterial blood gas tension

The strength of respiratory muscles can be evaluated from static measurement (PImax and PEmax) or inferred from dynamic measurement such as maximal voluntary ventilation. Maximal inspiratory pressure and Maximal expiratory pressure are simple, convenient and non-invasive measurement of respiratory muscle strength. Respiratory muscle strength decreases in COPD patients due to multiple factors. The primary aim of this study is to obtain mean PImax and PEmax values in Indian COPD patients and its co-rrelation with anthropomatric, physiological, spirometric parameters and arterial blood gas tension.

Relationship Between Respiratory Muscle Strength, Handgrip Strength, and Muscle Mass in Hospitalized Patients.

Minimal information is available to validate measurement of respiratory muscle strength (RMS) in the clinical setting. The purpose of this study was to determine the correlation between maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) with handgrip strength (HGS) and cross sectional muscle area obtained via diagnostic abdominal computed tomography (CT). Measures of MIP, MEP, SNIP, and HGS were obtained from individuals that participated in a previously published study; individuals who had an abdominal CT completed with (±)7 days of obtaining RMS measures were included. Both RMS and HGS were measured within 48-72 hours of admission; for RMS, the highest absolute (cm H2 O) and percent predicted values were recorded, and the average of 3 HGS measurements (kg) was documented. Cross-sectional muscle area (cm2 ) at the third lumbar region was recorded. Spearman's correlation coefficient was used to assess the relationship between variables. A total of 35 participants were included. HGS was correlated to absolute MIP (rs = 0.62, rs = 0.61), MEP (rs = 0.74, rs = 0.73), and SNIP (rs = 0.58, rs = 0.54) for males and females, respectively. Crosss-sectional muscle area was correlated with absolute MIP (rs = 0.66), MEP (rs = 0.58), and SNIP (rs = 0.783) for men and absolute SNIP (rs = 0.56) among women. Measures of RMS represent a promising assessment of muscle mass and function among hospitalized patients.

Noninvasive Prediction of Twitch Transdiaphragmatic Pressure: Insights from Spirometry, Diaphragm Ultrasound, and Phrenic Nerve Stimulation Studies

Background: Twitch transdiaphragmatic pressure (twPdi) following magnetic stimulation (MS) of the phrenic nerves is the gold standard for non-volitional assessment of diaphragm strength. Expiratory muscle function can be investigated using MS of the abdominal muscles and measurement of twitch gastric pressure (twPgas). Objectives: To investigate whether twitch pressures following MS of the phrenic and lower thoracic nerve roots can be predicted noninvasively by diaphragm ultrasound parameters and volitional tests of respiratory muscle strength. Methods: Sixty-three healthy subjects underwent standard spirometry, measurement of maximum inspiratory (PI_max) and expiratory pressure (PE_max), and diaphragm ultrasound. TwPdi following cervical MS of the phrenic nerve roots and twPgas after lower thoracic MS (twPgas-Thor) were measured using esophageal and gastric balloon catheters inserted transnasally. Using surface electrodes, compound muscle action potentials (CMAP) were simultaneously recorded from the diaphragm or obliquus abdominis muscles, respectively. Results: Forced expiratory flow (FEF_25–75) was significantly correlated with twPdi (r = 0.37; p = 0.003) and its components (twPgas and twitch esophageal pressure, twPes). Diaphragm excursion velocity during tidal breathing was correlated to twPes (r = 0.44; p = 0.02). No prediction of twitch pressures was possible from CMAP amplitude, forced vital capacity (FVC), or PI_max. TwPgas-Thor was correlated with FEF_25–75 (r = 0.46; p = 0.05) and diaphragm thickness at total lung capacity (r = 0.38; p = 0.04) but could not be predicted from CMAP amplitude, FVC, or PE_max. Conclusions: TwPdi and twPgas-Thor cannot be predicted from volitional measures of respiratory muscle strength, diaphragm and abdominal CMAP, or diaphragm ultrasound. Invasive recording of esophageal and gastric pressures following MS remains indispensable for objective assessment of respiratory muscle strength.