Maximum Expiratory Research Articles

Rehabilitation of Functional Dysphonia Using Semi-Occluded Vocal Tract Exercises (SVOTE)

This case study evaluated the efficacy of semi-occluded vocal tract (SVT) therapy as a speech intervention for functional dysphonia in a 53-year-old patient. Laryngoscopic examination revealed mild erythema and mucosal irregularity in the posterior third, edema, slight interarytenoid erythema, and phonatory hiatus in the posterior third of the posterior wall. Vocal assessments were conducted before and after rehabilitation, focusing on the perceptual, acoustic, and aerodynamic aspects. The treatment plan incorporated sustained, oscillatory, and transient occlusions over 10 sessions. The results showed enhanced voice timbre quality and normalization of the fundamental frequency appropriate for the patient's age and sex. The jitter, shimmer, and harmonic noise disturbances decreased, indicating improved wave stability and harmonic structure definition. The maximum expiratory and phonatory times, along with the s/z ratio, increased, leading to improved vocal efficiency. Additionally, the vocal risk indicator decreased, articulatory stability improved, and energy utilization became more efficient, resulting in more stable formants. The study concluded that SVT exercises produce positive vocal changes, suggesting that techniques aimed at modifying the vocal tract are effective for speech therapy rehabilitation in patients with functional dysphonia.

Functional performance of patients submitted to cardiac surgery with different levels of sleep quality: an observational study

ObjectiveTo describe pulmonary function, muscle strength and functional performance in the different qualities of sleep and the impact of this on the number of physiotherapeutic assistances. MethodsThis is an observational study. In the pre and post operative period, sleep behavior was evaluated using the Pittsburgh questionnaire. Patients were divided into three groups: Good Sleep Quality (GSQ), Poor Sleep Quality (PSQ) and Sleep Disordered (SDB). At this time, other tests were also performed, such as: 6-Minute Walk Test (6MWT), Sit and Stand Test (SST), gait speed test and Timed Up to Go (TUG), Medical Research Council (MRC), maximal inspiratory pressure and maximal expiratory, vital capacity and peak expiratory flow. The functional performance and lung function of each group were compared. ResultsA total of 105 people, undergoing cardiac surgery and admitted to hospital were evaluated, 33 with GSQ, 41 with PSQ and 31 with SD. Patients who were in the SDB group had a lower functional performance than the other groups. 6MWT (meters) in the GSQ was 499 ± 87, versus 487 ± 91 in the PSQ and 430 ± 78 in the SD (p = 0.02). In the SST (seconds) it was 10.4 ± 1.1 in the GQS, 11.1 ± 2.3 in the PSQ and 15.4 ± 2.1 in the SD (p = 0.04). Lung function and muscle strength did not differ between groups. Regarding the refusal to perform physical therapy, the SD group was more incident, the main reason being drowsiness. ConclusionBased on the results, we found that sleep quality interferes with functional performance and physical therapy assistance during the hospital stay in patients undergoing cardiac surgery.

Exercise Improves Respiratory Function, Body Fluid and Nitric Oxide in Hemodialysis Patients.

Emerging evidence suggests that resistance training (RT) can mitigate respiratory muscle weakness in hemodialysis (HD) patients. However, the underlying mechanisms responsible for these beneficial effects remain unclear. The purpose of this study was to assess the impact of periodized RT on respiratory muscle strength and its relationship with handgrip strength (HGS), fat-free mass (FFM), nitric oxide (NO), and interdialytic weight gain (IWG) in HD patients. Thirty-three patients were randomly assigned to two groups: control (CTL; n=18) and RT (n=15). The RT group did not perform any additional exercise training specific to the respiratory tract. Maximal inspiratory (MIP) and expiratory (MEP) pressures, peak expiratory flow (PEF), HGS, FFM, NO, and IWG were measured before and after the intervention period. Participants in the RT group engaged in a 24-week RT program, three times per week. RT resulted in significant improvements in MIP, MEP, PEF, as well as enhancements in HGS, FFM, NO, and IWG (p<0.05). Notably, inverse correlations were observed between MIP (r=-0.37, p=0.03) and PEF (r=-0.4, p=0.02) with IWG. Thus, the amelioration of HGS and FFM coincided with a reduction in respiratory muscle weakness among HD patients. Decreased IWG and increased circulating NO are plausible mechanisms contributing to these improvements.

Ultrasonic AccV: a potential indicator of peripheral arteriosclerosis in patients with chronic obstructive pulmonary disease

ObjectiveThis study aimed to investigate the risk factors for peripheral arteriosclerosis (PAS) and peripheral artery disease (PAD) in chronic obstructive pulmonary disease (COPD) patients and potential ultrasound indicators that could be used to improve detection.MethodOutpatients seeking care between January 1, 2017, and December 31, 2020, in The First Affiliated Hospital of China Medical University were prospectively recruited. Subjects were divided into COPD and non-COPD (control) groups, and the COPD group was further divided into PAD and non-PAD subgroup, at the same time, PAS and non-PAS subgroup. Indicators of PAD -ankle-brachial index (ABI), indicators of PAS- pulse wave velocity (PWV), and ultrasound indices -peak systolic blood flow velocity (PSV) and blood flow acceleration velocity (AccV) were compared.ResultSixty-nine (61.6%) of 112 enrolled subjects had COPD. COPD patients had higher age, and blood pressure (BP)lower than controls. Seventeen (24.6%) COPD patients had PAD, the prevalence of PAD increases with the decrease of lung function, and seven (16.3%) non-COPD patients had PAD, however, there was no significant statistical difference between COPD and non-COPD groups. Fifty (72.5%) COPD patients had PAS, and thirty-four (79.1%) non-COPD patients had PAS, however, there was also no significant difference. The PAS subgroup had higher age, body mass index(BMI), body fat percentage(BFP), lower FEV1 and FEV1/FVC, as well as higher levels of right brachial artery and left dorsalis pedis artery AccV. Factors that correlated with ABI were 6MWD, post-bronchodilator FEV1, FEV1/ FVC, and maximal middle expiratory flow between 75% and 25% of FVC. Age, BP, and 6MWD, but not pulmonary function, were associated with brachial-ankle PWV (baPWV). There was a positive correlation between baPWV and radial artery AccV bilaterally.ConclusionRadial artery AccV correlated well with baPWV, which suggests that ultrasound could be used to assess both morphological and functional changes in vessels, may serving as a better method to identify PAS in high-risk COPD patients.

Assessment of maximal inspiratory and expiratory pressures in skeletal Class II patients with different growth patterns.

To evaluate maximal inspiratory (MIP) and expiratory (MEP) pressures, which are reflective of respiratory muscle strength, in skeletal Class II patients with different growth patterns (horizontal, average, and vertical) and to correlate those with airway dimension. Patients with a Class II skeletal base seeking orthodontic treatment were assigned to the following groups: average, horizontal, and vertical growth pattern. The control group (n = 14) comprised patients with a Class I skeletal base and average growth pattern. Airway dimensions were obtained using cone-beam computed tomography scans, and a spirometer with a pressure transducer was used for assessment of MIP and MEP. Routine spirometry for assessment of lung function was also performed. No significant differences were found in maximal inspiratory and expiratory pressures for the study groups in comparison with the control group. Class I patients had significantly greater oropharyngeal and nasopharyngeal airway volumes compared with the study groups. No significant difference in minimal cross-section area of the airway was observed among groups. A weak positive correlation between maximal inspiratory pressure and airway volume was observed. Although Class I patients displayed significantly greater oropharyngeal and nasopharyngeal airway volumes, there was no significant difference in respiratory muscle strength or airway function between Class II patients with different growth patterns and the Class I control group. The findings underscore the significance of exploring factors beyond craniofacial growth patterns that may contribute to sleep-related breathing disorders.

Concurrent Validity of a Low-Cost Manometer for Objective Assessments of Respiratory Muscle Strength.

This study examined the agreement in maximal expiratory (MEP) and inspiratory (MIP) pressure readings between two digital manometers: (1) the MicroRPM - the gold-standard manometer for respiratory muscle strength testing; and (2) the LDM - a low-cost, commercially available, alternative manometer. Positive (MEP) and negative (MIP) pressures were simultaneously applied to the MicroRPM and LDM using a 3-liter syringe within a controlled laboratory setting. Pressure readings were compared, and agreement was analyzed using Lin's concordance correlation (ρc ). Agreement was interpreted as 'poor' if <0.90, 'moderate' if 0.90 - <0.95, 'substantial' if 0.95 - <0.99, and 'excellent' if ≥0.99. Twenty percent of the pressure trials were repeated by a second researcher to examine test-retest reliability. A total of 150 trials were completed, ranging from -167 to +208 cmH2 O. There was a median absolute difference of 0.3 cmH2 O in pressure readings between the MicroRPM and the LDM. Lin's concordance correlation revealed 'excellent' agreement between the LDM and MicroRPM devices, with test-retest reliability assessment revealing 'substantial-to-excellent' agreement between the LDM and MicroRPM devices, with a concordance correlation coefficient of ρc = 0.999 (95% CI: 0.999-0.999). There was a median difference of 1.0% in MEP and MIP pressure readings consistently observed between the LDM and MicroRPM. Despite these relatively small differences, excellent agreement between the two manometers was present. These data suggest the LDM may be a valid, lower cost alternative to the MicroRPM for objectively assessing respiratory strength in clinical practice; however, additional research is needed in healthy adults and in patient populations. NA Laryngoscope, 134:1831-1836, 2024.

Respiratory Muscle Strength in Brazilian Adolescents: Impact of Body Composition

(1) Introduction: Studies on respiratory muscle strength (RMS) in adolescents are controversial. Few studies so far have investigated respiratory muscle strength in Brazilian adolescents and the impact of body composition on it. (2) Objective: to evaluate the respiratory muscle strength of Brazilian adolescents and compare this with nationally and internationally predicted normality values. (3) Method: A cross-sectional study (CAEE: 34634414.5.0000.5479) was carried out with 98 adolescents, where both sexes were divided into four groups: eutrophic (n = 44); overweight (n = 15), obese (n = 25), and severely obese (n = 14). All were submitted to an anthropometric assessment, body composition analysis and manovacuometry. To interpret the results, Analysis of Variance (ANOVA) with Turkey’s post hoc test was used. The Kruskal–Wallis test and Friedman’s post hoc test were used to compare the observed vs. proposed results. A p-value &lt; 0.05 was considered statistically significant. (4) Results: There were no differences among the groups for maximal inspiratory (MIP) and expiratory (MEP) pressures. However, when considering the total sample, we could say that RMS was higher among boys, and there were no significant differences in RMS in relation to the maturational stage. The values obtained for MIP were lower than those suggested for the national equation and higher than those proposed for the international equation. Similarly, the values obtained for MEP were lower than those suggested for the national and international equation. (5) Conclusions: RMS was similar in adolescents with different body compositions and different maturation stages. Adiposity did not interfere with RMS in adolescents. Boys had higher MIP and MEP values compared to girls. Therefore, the reference values proposed by the equations do not consistently match RMS in the adolescents studied. This context reinforces the need for new studies that are related to RMS to establish normality values and propose equations that represent the youth population.

Pulmonary function tests reveal unrecognised lung dysfunction and have independent prognostic significance in patients with systemic AL amyloidosis

Background Lung involvement in AL amyloidosis is not very common, but post-mortem data and retrospective studies suggest it is likely underrecognized. Aim To perform a comprehensive evaluation of lung function with pulmonary function tests (PFTs) in patients with newly diagnosed AL amyloidosis. Methods A prospective, non-interventional study of 139 consecutive patients with newly diagnosed AL amyloidosis. Results PFTs indicated normal breathing physiology in 68% of patients, obstructive in 9% and restrictive in 23%; the latter was associated with worse survival (28.6 vs 76 months for obstructive/normal physiology, p = 0.002) and remained significant after adjustment for Mayo stage and abnormal chest-CT. Forced vital capacity <80% of predicted value, forced expiratory volume <80% of predicted value, and carbon monoxide diffusion capacity <70% were independently associated with poorer survival. Respiratory muscle strength (as assessed by maximal expiratory (Pe) and inspiratory (Pi) pressure) was affected in most patients (64% had Pi < 55% and 57% had Pe < 70% of predicted values). Pe% was an independent prognostic factor for survival (HR: 0.984 per 1% unit increase, p = 0.007). Conclusions Pulmonary dysfunction, as assessed with PFTs, is common and underrecognized in patients with systemic AL amyloidosis, with significant prognostic and potentially therapeutic implications, independent of the degree of cardiac dysfunction or chest-CT findings.

Respiratory Muscle Strength in Patients with Coronary Heart Disease and Different Musculoskeletal Disorders

Aim. To measure respiratory muscle strength (RMS) in patients with coronary heart disease (CHD) and different musculoskeletal disorders (MSD).Material and methods. Patients were divided in four groups according to the MSD. Group I included 52 (13.4%) patients with sarcopenia, group II included 28 (7.2%) patients with osteopenia, group III included 25 (6.5%) patients with osteosarcopenia, group IV included 282 (72.9%) patients without MSD. All patients underwent the assessment of maximal expiratory (МЕР) and maximal inspiratory mouth pressures (MIP).Results. The mean RMS values were lower than the normative values, and the strength of the expiratory muscles was 1.25 times lower compared to the inspiratory muscles. Both of these parameters were within the normal range in 191 (49.3%) patients, and lower values were noted in 196 (50.7%). An isolated decrease in MIP was observed in 24.8% of patients, an isolated decrease in МЕР in 6.5%, a combined decrease in MIP and МЕР in 19.4% of patients. Comparative analysis of МЕР and MIP (depending on the MSD) did not demonstrate statistically significant differences. Lower МЕР (76.9%) and MIP (75%) values were noted mainly in the group of patients with sarcopenia. A similar pattern was notes in patients with osteosarcopenia and in patients without MSD. Normative values of RMS were observed in patients with osteopenia. Correlation analysis revealed a unidirectional relationship between RMS and the parameters of muscle function (hand grip strength, muscle area and musculoskeletal index) and a multidirectional relationship between МЕР and BMI (r -0.743, p=0.013), MIP and patient age (r -0.624, p=0.021).Conclusion. Respiratory muscle weakness was diagnosed in half of the patients with coronary heart disease. There were no statistically significant differences in RMS between patients with MSD and isolated CHD, despite lower values in the group with MSD. Correlation analysis revealed an association between RMS and muscle function.

The rationale of applying inspiratory/expiratory muscle training within the same respiratory cycle in children with bronchial asthma: a placebo-controlled randomized clinical investigation

Objective Even though positive implications of inspiratory muscle training (In-MT) have been established in children and adolescents with bronchial asthma (C/AwBA), the role of combined inspiratory and expiratory muscle training (Ex-MT) within the same respiratory cycle (In/Ex-SC) is still unknown. This study was, therefore, set out to explore the effect of In/Ex-SC on respiratory muscle strength, pulmonary functions, and control of asthma symptoms in C/AwBA. Methods This was a placebo-controlled randomized clinical investigation that included 51 C/AwBA (12-18 years). Participants were assigned randomly into three groups: Placebo, In-MT only, or combined In/Ex-SC training (n = 17, each group). The training was conducted for ∼35 min, thrice/week over 12 weeks. The maximal inspiratory (IPmax) and expiratory (EPmax) pressure (indicating the strength of the inspiratory and expiratory muscles, respectively), pulmonary functions [forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC index], and asthma control test (ACT) were assessed before and after the intervention. Results The In/Ex-SC yielded larger increases in IPmax and EPmax than either the Placebo training (P=.031 and P=.009 respectively) or the In-MT (P=.029 and P=.032 respectively). Further, In/Ex-SC produced favorable improvement in FEV1, FVC, and FEV1/FVC compared to the Placebo training (P=.001, P=.004, and P=.0005 respectively) or In-MT (P=.038, P=.037, and P=.025 respectively) training. Furthermore, In/Ex-SC led to better control of asthma symptoms than the Placebo (P<.001) or In-MT (P=.002) training. Conclusion This study provides evidence that combined In/Ex-SC can considerably improve respiratory muscle strength, enhance pulmonary function, and promote control over asthma symptoms in C/AwBA.

Respiratory muscle strength, exercise capacity and physical activity in patients with primary ciliary dyskinesia: A cross-sectional study

Background and objectivesThe pathophysiological mechanisms of primary ciliary dyskinesia (PCD) may affect many functions, including respiratory, physical, and health status. This study aimed to compare respiratory muscle strength, inspiratory muscle endurance, muscle strength, exercise capacity, physical activity levels, and quality of life in PCD patients and controls. MethodsTwenty-seven patients and 28 controls were included. Respiratory muscle strength (maximal inspiratory (MIP) and maximal expiratory (MEP) pressures), inspiratory muscle endurance (incremental threshold loading test), muscle strength (quadriceps femoris, shoulder abductor, elbow flexor, handgrip), exercise capacity (6-min walk test (6MWT)), physical activity and quality of life (QOL-PCD) were evaluated. ResultsMIP, inspiratory muscle endurance, quadriceps femoris, and handgrip muscle strength, 6MWT distance, total energy expenditure; childrens' (6–12 years) and their parents' physical function, upper, lower respiratory, and hearing symptoms and treatment burden QOL-PCD subscales scores were significantly lower in patients compared with controls (p < 0.05). The 66.7% of patients did not meet the optimal number of steps. MEP, shoulder abductor, and elbow flexor muscle strength, active energy expenditure, physical activity duration, average metabolic equivalents, number of steps, lying time, and sleep duration; childrens' and their parents' other subscales and adolescents’ all QOL-PCD subscales scores were similar between groups (p > 0.05). ConclusionInspiratory muscle strength and endurance, lower extremity and total muscle strength, exercise capacity, total energy expenditure, and childrens’ quality of life are impaired compared to healthy controls. Decreased physical activity level is prevalent in these patients. Effects of pulmonary rehabilitation on these impaired outcomes for PCD patients should be investigated. Trial registrationClinicaltrials.gov: NCT03370029; December 12, 2017.

Low-Cost Open-Source Device to Measure Maximal Inspiratory and Expiratory Pressures.

The measurement of maximal inspiratory (MIP) and maximal expiratory (MEP) pressures is a widely used technique to non-invasively evaluate respiratory muscle strength in clinical practice. The commercial devices that perform this test range from whole body plethysmographs to portable spirometers, both expensive and include a wide range of other respiratory tests. Given that a portable, low-cost, and specific option for MIP and MEP measuring device is not currently available in the market. A high-performance and easy-to-build prototype has been developed and the detailed technical information to easily reproduce it is freely released. A novel device is based on an Arduino microcontroller with a digital display, an integrated pressure transducer, and three-dimensional (3D) printed enclosure (total retail cost €80). The validation of the device was performed by comparison with a laboratory reference setting, and results showed accuracy within ±1%. As the device design is available according to the open-source hardware approach, measuring MIP/MEP can greatly facilitate easily available point-of-care devices for the monitoring of patients and, most important, for making this lung function measurement tool affordable to users in low- and middle-income countries.

Pulmonary Function and Respiratory Muscle Strength in Patients with Multiple Sclerosis.

Background In patients with multiple sclerosis (MS), there is a decline in muscle strength and physical capacity due to demyelination and axonal loss in the central nervous system. In patients with advanced MS or in a later stage of the disease, also respiratory impairment may occur. The degree of pulmonary dysfunction in the earlier stages of MS has not been thoroughly described. Therefore, the primary aims of this study are to describe pulmonary function and respiratory muscle strength in patients with a moderate disease course and to identify associations between respiratory muscle strength and functional capacity. Methods A sample of 48 patients with a diagnosis of MS and mean age 56 ± 11 years was studied using a descriptive cross-sectional design. The patients had a disease duration of 24 ± 11 years and a median Expanded Disability Status Scale (EDSS) score of 4.5 (interquartile range 4.0-6.5). Pulmonary function assessed by spirometry, respiratory muscle strength, peak cough flow and peripheral oxygen saturation, subjective breathing and coughing ability, and physical capacity measured using the 6MWT were evaluated. Results The patients had normal pulmonary function with no significant abnormalities in dynamic spirometry (vital capacity 103 ± 16% predicted, forced expiratory volume in 1 second 95 ± 15% predicted). Peak expiratory flow rate 89 ± 17% predicted was in the lower limit of normal. Respiratory muscle strength, determined by maximal inspiratory (MIP) and expiratory (MEP) static pressures, was normal but with large differences between individuals. MIP ranged from 26 to 143 cmH2O (98 ± 31% predicted); the MEP values ranged from 43 to 166 cmH2O (104 ± 29% predicted), with two patients having values below the lower limit of normal. Significant positive associations between MIP as well as MEP were found in several pulmonary function variables. A significant negative association was found between EDSS score and MEP (r = −0.312, p = 0.031). Mean peak cough flow was 389 ± 70 L/min, which is comparable with the values reported for healthy adults. The patients did not experience a severely decreased ability to take deep breaths or cough. There was a moderate correlation between MEP and physical capacity, as assessed by the 6MWT (r = 0.399, p = 0.010) and between peak expiratory flow (PEF) and the 6MWT (r = 0.311, p = 0.048). Conclusion Respiratory muscle strength, pulmonary function assessed by spirometry, and peak cough flow were normal in patients with mild to moderate MS; however, there were large individual differences demonstrating low respiratory muscle strength in some patients. Significant associations between MEP and functional capacity and between MEP and disease severity were found, indicating that patients with impaired respiratory muscle strength have lower functional capacity and more severe disease.

Influence of Lung Hyperinflation on Respiratory Muscles Pressures During a Submaximal Test in Patients With COPD: A Clinical Perspective

Background and Objective: Reduction of exercise tolerance is associated with expiratory flow-limitation (EFL) and lung hyperinflation; those are only partially reversible to bronchodilator. Lung hyperinflation lowers the diaphragm muscle provoking a mechanical disadvantage that, eventually, reduces maximal inspiratory (MIP) and expiratory (MEP) pressures. We aimed to assess the influence of the dynamic lung hyperinflation on respiratory pressures changes at rest and after a submaximal exercise test in COPD patients with and without a bronchodilator. Methods:: We prospectively analyzed 16 COPD patients (FEV1 36.4±10% pred.; age 61.0±8 years, height 165±12 cm and BMI 25.9±6 kg/m2). MIP and MEP were measured before and after performing the six minutes walking test (6MWT) with and without bronchodilator (400 mcg of albuterol). Results:: Nine of 16 patients increased IC more than 150 ml after bronchodilator use. Right after the 6MWT was accomplished without bronchodilator, IC decreased by 7.05% as compared to the 6MWT baseline value (p&lt;0.01). Nine patients decreased IC more than 150ml. After bronchodilator use, patients performed the 6MWT without any IC significant reduction (p&gt;0.05). Twelve patients increased the MIP (ranging from 70±11cmH2O to 77±10cmH2O, p = 0.0043) using 400mcg of albuterol. Thirteen patients reduced MIP after the 6MWT without bronchodilator use (p &lt;0.007). There was no significant reduction (p&gt; 0.05) in MIP when patients performed the 6MWT after bronchodilator use. We also found a significant correlation between MIP and inspiratory capacity (IC) and MEP and the IC before and after the 6MWT (r=0.61, p=0.0054; r=0.60, p=0.0031, respectively). Conclusions:: Dynamic pulmonary hyperinflation directly interferes with the ability of respiratory muscles to generate inspiratory and expiratory pressures. The previous use of bronchodilators in patients with COPD reduced dynamic hyperinflation when accomplishing a sub-maximal exercise.

Respiratory muscle strength and quality of life in chronic kidney disease patients undergoing hemodialysis

Abstract Introduction: Hemodialysis (HD) sessions associated with the chronic kidney disease (CKD) repercussions may cause respiratory muscle impairment and limitations of daily living activities, which may compromise the quality of life. Objective: To evaluate respiratory muscle strength and quality of life in HD patients. Methods: A cross-sectional study involving CKD patients of both sexes undergoing HD. All were evaluated during HD, using an evaluation form containing personal and clinical data, presence of comorbidities, lifestyle (including self-reported physical activity) and vital signs. Respiratory muscle strength was analyzed by maximum inspiratory (MIP) and maximum expiratory (MEP) pressures by manovacuometer and quality of life using the SF-36 questionnaire. Results: Sixty-eight patients were evaluated (69.1% men), with a mean age of 54.9 ± 13.6 years. The MEP% was below of predicted (79.5 ± 25.7) and the MIP% was reduced only in women (77.8 ± 38.7). The MIP% was related to CKD time (p = 0.04) in men. The SF-36 domain that showed the most impairment was physical limitation [25.0 (13.0-67.0)], while mental health was the least impaired domain [72.0 (62.0-84.0)]. Those who reported the practice of physical activity obtained better results in vitality domain (p = 0.01). In the analysis stratified by sex, the functional capacity domain was less compromised in men who practiced self-reported physical activity (p = 0.02). Conclusion: CKD patients undergoing HD had a reduction in MEP relative to predicted, in addition to a greater impairment of MIP in men with longer CKD time and in women alone, although the clinical relevance of this finding is uncertain. Quality of life was more compromised in the physical limitation domain, where those who self-reported physical activity achieved better results in the domains of vitality (total sample) and functional capacity (men).

Analysis, Design, and Experiment of FVC Detection Device Using the Cross Four-Electrode Method

The early screening and prevention of chronic respiratory diseases are very important. To achieve the monitoring and management of chronic obstructive pulmonary disease (COPD), this article proposes a new lung impedance measurement method, which uses a cross four-electrode structure. It effectively solves the problems of noncompliance of traditional instruments, risk of cross-infection, and nononline monitoring. Compared with the traditional impedance measurement method, the measurement accuracy of lung function parameters is improved. Using the detection device, the equivalent impedance of the chest was rapidly measured from two orthogonal directions when the people were in the same breath state. The maximum expiratory and inspiratory thoracic impedance was obtained by analyzing 30 samples. The measurement of lung function parameters is realized by solving the change value of impedance and its relationship with the chest circumference. Experiments proved that the cross four-electrode method could consider the two directions of equivalent thoracic impedance, enrich the measurement parameters of thoracic impedance, and make the test results of pulmonary function parameters have good consistency with the results of standard methods. Correlation coefficients of test indexes forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were 0.967 and 0.955 respectively. The consistency boundary diagram showed that more than 95% of monitoring data of the subjects fell within the scope of the consistency boundary, and the maximum relative error of measurement was only 4.65%.

RESPIRATORY MUSCLE IMPAIRMENT EVALUATED WITH MEP/MIP RATIO IN CHILDREN AND ADOLESCENTS WITH CHRONIC RESPIRATORY DISEASE.

ABSTRACTObjective: To evaluate the strength of respiratory muscles and to compare maximum inspiratory (MIP) and expiratory (MEP) pressure and MEP/MIP ratio between patients with chronic respiratory diseases and healthy individuals.Methods: Case-control study. Individuals with neuromuscular disease and post-infectious bronchiolitis obliterans were considered. In addition, they were also matched according to anthropometric and demographic characteristics with healthy children and adolescents. MIP, MEP in the three groups, and pulmonary function only in patients with chronic respiratory diseases were recorded.Results: A total of 52 subjects with CRD (25 with neuromuscular disease, and 27 with post-infectious bronchiolitis obliterans) and 85 healthy individuals were included, with an average age of 11.3±2.1 years. Patients with neuromuscular disease and post-infectious bronchiolitis obliterans presented lower MIP and MEP when compared with healthy individuals, although MEP/MIP ratio was lower in patients with neuromuscular disease (0.87±0.3) and higher in patients with post-infectious bronchiolitis obliterans (1.1±0.3) compared to the healthy group (0.97±0.2). Only in patients with neuromuscular disease a negative correlation was observed between MEP/MIP ratio and age (r=-0.50; p=0.01).Conclusions: Differences in the pattern of muscular weakness between patients with chronic respiratory diseases were observed. In patients with neuromuscular disease, a decrease in the MEP/MIP ratio depending on MIP was verified; and in those patients with post-infectious bronchiolitis obliterans, an increase in the MEP/MIP ratio depending on MIP was also observed.

Abstract 16698: Cardiopulmonary Exercise Testing With an In-Line Filter During the COVID-19 Pandemic

Introduction: During maximum incremental exercise expiratory flow rates increase &gt; 10-fold and minute ventilation can exceed 100L/min, raising concern for possible spread of COVID-19 in asymptomatic patients undergoing exercise testing. Moreover, use of surgical or N95 masks that limit airflow are recognized to limit the ability to perform maximum exercise. Hypothesis: Use of an in-line filter during cardiopulmonary exercise testing is feasible and will not adversely impact measurements of exercise capacity. Methods: We conducted a proof-of-principle study in which a commercially available electrostat filter (Figure 1A), which has &gt;99.9% viral efficiency without affecting spirometry measurements during pulmonary function testing, was placed in-line, upstream of the flow meter and gas analyzer sample line for use during cardiopulmonary exercise testing. A single healthy subject completed incremental exercise with a 3 min period of unloaded exercise followed by 4-min stages of exercise at 50, 100, 150, and 200W with and without the filter in place on the same day. Mechanical dead space was 53 ml with the filter and 45 ml without. Results: In comparison to no internal filter, use of an in-line filter resulted in VO 2 measurements of 99%, 97%, 98%, and 97% during 50W, 100W, 150W, and 200W, respectively (Figure 1A). VO 2 /work slope measurements and measurements of minute ventilation were also highly consistent throughout exercise with and without use of an in-line filter (Figure 1B). Conclusions: Exercise testing is an integral part of cardiovascular care delivery. Our findings require further validation but suggest that an in-line filtration system can be utilized in an effort to reduce droplet and viral dissemination without impacting measures of cardiopulmonary performance.

Respiratory function in chronic primary fibromyalgia

Since patients with severe chronic primary fibromyalgia (CPF) report effort dyspnoea, respiratory function was studied in 87 consecutive women with CPF according to Yunus' criteria. Bernstein spirometry, maximum inspiratory (MIP) and expiratory (MEP) pressures were obtained in patients, and in a reference group of 61 healthy women. MIP was considerably lower in patients than in controls (3.6 +/- 2.0 vs. 8.0 +/- 2.2 kPa, p less than 0.0001), as was MEP (3.1 +/- 2.1 vs. 8.3 +/- 2.2 kPa, p less than 0.0001). Patients who had previously reported dyspnoea at a bicycle exercise test showed significantly lower values of respiratory pressures than patients without dyspnoea. Respiratory pressures were reproducibly low in CPF patients. Spirometric values were normal among patients and controls. We conclude that maximum expiratory and inspiratory pressures are low in CPF, a finding which may indicate respiratory muscle dysfunction in this syndrome.

Assessment of the strength of the respiratory muscles in the early stages after thoracic interventions

Introduction. The respiratory complications prevail among the causes of postoperative mortality in the thoracic surgery. The respiratory muscle (RM) dysfunction may be considered as one of the most important pathogenetic factors of such complications. Aim. To evaluate the RM strength in the early postoperative period after thoracic surgery. Materials and methods . 52 patients were examined after elective thoracoscopy and thoracotomy surgery. The first group consisted of 24 patients with duration of the operation for 90 minutes and the less. The second group included 28 persons with duration of the surgery for more than 90 minutes. RM strength was measured using “MicroRPM” (CareFusion, UK). Maximal inspiratory (MIP), expiratory (MEP) and nasal (SNIP) pressure indicators were estimated at the following time points: before surgery, in 60 minutes, 180 minutes and 24 hours after extubation. Results. The significant differences between the strength indicators of RM were revealed inside the both groups at the different phases of the investigation. The drastic drop of all the strength indicators in comparison with the initial values was detected in 60 minutes after the extubation in the patients of both groups. The values increased in 180 minutes. 24 hours after the surgery the readings of RM strength retained the growth trend, but they did not reach the initial values. Evaluation of the remainder between RM strength indicators before the surgery and at the specific time point revealed the significant differences between the compared groups in the terms of the reduction extent for MIP at all the time points, and for SNIP in 180 minutes after extubation only. Conclusion. These data show the more evident dynamics of RM strength restoration with thoracoscopic techniques being used, which allowed to decrease the surgery duration and to reduce cumulative dose of the muscle relaxant.