Measurement Of Maximal Inspiratory Pressure Research Articles

Unveiling the Respiratory Muscle Strength in Duchenne Muscular Dystrophy: The Impact of Nutrition and Thoracic Deformities, Beyond Spirometry.

Duchenne muscular dystrophy (DMD) is the most prevalent progressive muscular dystrophy, and the guidelines recommend the regular assessment of respiratory muscle function. This study aimed to assess the relationship between maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP) and sniff nasal inspiratory pressure (SNIP) measurements and upright-supine spirometry parameters in children with DMD, the predictability of upright-supine spirometry in terms of diaphragm involvement, and the impact of nutrition on muscle strength. This prospective cross-sectional study examined patients with DMD by comparing upright and supine FVC, MIP, MEP, and SNIP measurements. The effects of the ambulatory status, kyphoscoliosis, chest deformity, and low BMI on respiratory parameters were investigated. Forty-four patients were included in the study. The mean patient age was 10.8 ± 2.9 years. Twenty-five patients were ambulatory. A significant decrease in FVC, FEV1, and FEF25-75 values was detected in the supine position in both ambulatory and non-ambulatory patients (p < 0.05). All patients had low MIP, MEP, and SNIP measurements (less than 60 cm H2O). MIP, MEP, and SNIP values were significantly lower in patients with a low BMI than in those without (p < 0.05). To accurately assess respiratory muscle strength, supine FVC should be combined with upright FVC, MIP, MEP, and SNIP measurements. It is crucial to regularly screen patients for nutrition, as this can significantly affect respiratory muscle function during pulmonology follow-up.

Evaluation of patients with chronic obstructive pulmonary disease by maximal inspiratory pressure and diaphragmatic excursion with ultrasound sonography

BackgroundDecreased respiratory muscle strength and muscle mass is key in diagnosing respiratory sarcopenia. However, the role of reduced diaphragm activity, expressed as the maximal level of diaphragmatic excursion (DEmax), in diagnosing respiratory sarcopenia in patients with chronic obstructive pulmonary disease (COPD) remains unclear. This study aimed to characterize patients with COPD and low DEmax and maximal inspiratory pressure (MIP), a measure of inspiratory muscle strength, and assess the role of DEmax in respiratory sarcopenia. MethodsPatients with COPD underwent spirometry, exercise tolerance (VO2peak) test, and MIP measurement. DEmax and sternocleidomastoid thickness at the maximal inspiratory level (TscmMIL) were assessed using ultrasound sonography. ResultsOverall, 58 patients with COPD (median age, 76 years; median %FEV1, 51.3 %) were included, 28 of whom showed a %MIP of ≥80 %, defined as having preserved MIP. Based on the %MIP of 80 % and median value of DEmax (48.0 mm) as thresholds, the patients were stratified into four groups: both-high (n = 18), %MIP-alone low (n = 11), DEmax-alone low (n = 10), and both-low (n = 19) groups. The both-low group exhibited the lowest %FEV1, Δinspiratory capacity, VO2peak, and TscmMIL, and these values were significantly lower than those of the both-high group. Except for %FEV1, these values were significantly lower in the both-low group than in the %MIP-alone low group despite adjusting DEmax level for body mass index. ConclusionMeasuring DEmax along with MIP can characterize patients with COPD, reduced exercise capacity, and decreased accessory respiratory muscle mass and can help diagnose respiratory sarcopenia.

The Relationship between Exercise Capacity and Muscle Strength, Physical Activity, Fatigue and Quality of Life in Patients with Cancer Cachexia

Background Exercise capacity is a significant determinant of mortality for cancer patients, so knowing the possible determinants of exercise capacity will produce physical and psychological benefits for individuals with cancer cachexia. Purpose To investigate the relationship between exercise capacity on peripheric and respiratory muscle strength, physical activity, fatigue and quality of life in subjects with cancer cachexia. Methods The study included 31 patients diagnosed with cancer cachexia. Functional capacity was assessed by 6-Minute Walk Test, hand grip strength and proximal muscle mass by hand dynamometer, respiratory muscle strength by the Maximum Expiratory Pressure and Maximum Inspiratory Pressure measurements, physical activity by International Physical Activity Questionnaire Short Form, fatigue by Brief Fatigue Inventory, and quality of life by EORT-QLQ-C30. The relationship between functional capacity and continuous independent variables was determined using Spearman’s or Pearson’s tests. Results A strong positive correlation was observed between exercise capacity and expiratory muscle strength (r = 0.75, p < 0.001), activity level (r = 0.68, p < 0.001), and quality of life global health status (r = 0.74, p < 0.001). Conversely, a strong negative correlation was found between exercise capacity and fatigue severity (r = −0.64, p < 0.001). Conclusion Higher exercise capacity in cancer cachexia patients is linked to reduced fatigue, improved respiratory muscle strength, increased physical activity levels, and enhanced quality of life. When designing rehabilitation programs or exercise interventions for individuals with cancer cachexia, it is crucial to assess their exercise capacity and tailor the programs accordingly.

Managing respiratory muscle weakness during weaning from invasive ventilation.

Weaning is a critical stage of an intensive care unit (ICU) stay, in which the respiratory muscles play a major role. Weakness of the respiratory muscles, which is associated with significant morbidity in the ICU, is not limited to atrophy and subsequent dysfunction of the diaphragm; the extradiaphragmatic inspiratory and expiratory muscles also play important parts. In addition to the well-established deleterious effect of mechanical ventilation on the respiratory muscles, other risk factors such as sepsis may be involved. Weakness of the respiratory muscles can be suspected visually in a patient with paradoxical movement of the abdominal compartment. Measurement of maximal inspiratory pressure is the simplest way to assess respiratory muscle function, but it does not specifically take the diaphragm into account. A cut-off value of -30 cmH2O could identify patients at risk for prolonged ventilatory weaning; however, ultrasound may be better for assessing respiratory muscle function in the ICU. Although diaphragm dysfunction has been associated with weaning failure, this diagnosis should not discourage clinicians from performing spontaneous breathing trials and considering extubation. Recent therapeutic developments aimed at preserving or restoring respiratory muscle function are promising.

Monitoring Respiratory Effort and Lung-distending Pressure Noninvasively during Mechanical Ventilation: Ready for Prime Time.

Monitoring Respiratory Effort and Lung-distending Pressure Noninvasively during Mechanical Ventilation: Ready for Prime Time.

Respiratory function of children and adolescents with osteogenesis imperfecta: respiratory muscle strength, forced vital capacity, and peak expiratory flow.

This study aims to evaluate the respiratory function of children and adolescents with osteogenesis imperfecta (OI) followed up at a referral center. A cross-sectional study was conducted with a non-probabilistic sample. Manovacuometry was performed with the measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), and in addition, peak expiratory flow (PEF) and ventilometry were performed to measure forced vital capacity (FVC). In total, 23 individuals were evaluated, with a mean age of 11.6±3.4 years, 56.5% of whom were females. Regarding the classification of OI, 56.5% of the sample belonged to type IV, 30.5% to type III, and 13% to type I. The mean MIP was 64.4% of the predicted, and the mean MEP was 56.2% of the predicted. Overall, the mean PEF was 213.9 L/min, but only 140.6 L/min in the OI type III group. Median FVC was 1.9 L, corresponding to 110% of the predicted. Respiratory function of the study subjects was altered, with respiratory muscle strength values lower than expected in the whole sample, and peak expiratory flow was significantly reduced in the OI type III group.

P251 PERIODIC BREATHING (EOV) ON CARDIORESPIRATORY STRESS TESTING: ARE THERE PROGNOSTIC DIFFERENCES BETWEEN PATIENTS WITH PERIODIC BREATHING THAT PERSISTS THROUGHOUT THE TEST AND PATIENTS TO WHOM IT DISAPPEARS?

Abstract Introduction Oscillatory exercise ventilation (EOV) is frequently seen in patients with severe heart failure (HF) and has a ne:gative prognostic value in both patients with reduced HF and those with average ejection fraction. Two types of EOV have been described one that lasts throughout exercise and one that disappears before the end of exercise, Figure 1 Aim of the Study It is currently unknown whether there are differences in prognosis and functional capacity between HF patients with EOV that persists or disappears during exercise. Population Male and female patients, aged≥18 years, diagnosed with HF and LVEF&amp;lt;45% were enrolled. Methods The retrospective study enrolled patients who performed a cardiopulmonary exercise test (CPET) and presented with EOV during exercise (Monzino Heart Center Laboratory and patients included in the MECKI score registry, identified a total of 255 patients). A subset of 100 patients underwent measurement of maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) before and after exercise (Table 2). All patients were treated at the top of therapy for HF. CPETs were performed and analyzed with a standard approach using a customized ramp protocol. The main parameters obtained are reported and compared in Table 1. EOV was defined according to as a cyclic fluctuation in ventilation as proposed by Corrà et al. Statistical analysis:Data are reported as mean ± standard deviation or median and interquartile range as appropriate. The two groups of patients were compared by t test for unpaired data in the case of data with normal distribution. Mortality was analyzed by Kaplan Meier curves and Log Rank test. Survival was considered using the composite end–point of cardiovascular death, urgent cardiac transplantation, or implantation of a left ventricular assist device. The median MECKI score of the total population was 5.5% (2.5–13.7) with no significant differences between the 2 groups. Figure 1 shows the Kaplan Meyer describing the 5–year survival analysis in both groups. Conclusions Patients with disappearing EOV demonstrated better exercise performance but no significant difference in survival and major prognostic parameters.

The Value of Physiotherapeutic Tests Next to Cardiopulmonary Exercise Test to Assess Exercise Capacity in Left Ventricular Assist Device Patients

Purpose Quality of life in advanced heart failure patients treated with left ventricular assist device (LVAD) is largely determined by exercise capacity, for which cardiopulmonary exercise test (CPET) is the gold standard. The complexity of CPET frequently leads to inconclusive results due to functional impairment early after LVAD implantation. Physiotherapeutic tests have been opted as an alternative for CPET in LVAD patients. To evaluate the value of physiotherapeutic tests next to CPET in assessing exercise capacity after LVAD implantation. Methods Patients who underwent LVAD implantation between January 2015 and July 2019 in our center were included if both a regular CPET and physiotherapeutic tests were performed. At 3-6 months physiotherapeutic tests consisted of a 6-minute walking test (6MWT), measurement of maximal inspiratory pressure (MIP) and grip strength. After univariable analysis using Pearson correlation, stepwise multivariable linear regression was performed to assess the association of physiotherapeutic parameters with CPET. Results 147 patients received an LVAD of which 79 (53.7%) performed both CPET and any of the physiotherapeutic tests at 3-6 months. 6MWT, grip strength and MIP were significantly correlated with VO2 max, of which 6MWT was the strongest (R=0.55, p<0.001). Grip strength was moderately correlated to VO2 max (R=0.48, p<0.001), MIP correlated weakly (R=0.30, p=0.033). Stepwise multivariate analysis showed that the combination of 6MWT and grip strength were independently associated with VO2 max (R=0.65, adjusted R2=0.41, p<0.001; Table 1). MIP was not significantly associated with VO2max in the multivariate model, and was therefore excluded from our model. Conclusion Of the physiotherapeutic tests at 3-6 months after LVAD implantation, 6MWT was best correlated with VO2max. The combination of 6MWT and grip strength significantly improved the association with VO2max. Quality of life in advanced heart failure patients treated with left ventricular assist device (LVAD) is largely determined by exercise capacity, for which cardiopulmonary exercise test (CPET) is the gold standard. The complexity of CPET frequently leads to inconclusive results due to functional impairment early after LVAD implantation. Physiotherapeutic tests have been opted as an alternative for CPET in LVAD patients. To evaluate the value of physiotherapeutic tests next to CPET in assessing exercise capacity after LVAD implantation. Patients who underwent LVAD implantation between January 2015 and July 2019 in our center were included if both a regular CPET and physiotherapeutic tests were performed. At 3-6 months physiotherapeutic tests consisted of a 6-minute walking test (6MWT), measurement of maximal inspiratory pressure (MIP) and grip strength. After univariable analysis using Pearson correlation, stepwise multivariable linear regression was performed to assess the association of physiotherapeutic parameters with CPET. 147 patients received an LVAD of which 79 (53.7%) performed both CPET and any of the physiotherapeutic tests at 3-6 months. 6MWT, grip strength and MIP were significantly correlated with VO2 max, of which 6MWT was the strongest (R=0.55, p<0.001). Grip strength was moderately correlated to VO2 max (R=0.48, p<0.001), MIP correlated weakly (R=0.30, p=0.033). Stepwise multivariate analysis showed that the combination of 6MWT and grip strength were independently associated with VO2 max (R=0.65, adjusted R2=0.41, p<0.001; Table 1). MIP was not significantly associated with VO2max in the multivariate model, and was therefore excluded from our model. Of the physiotherapeutic tests at 3-6 months after LVAD implantation, 6MWT was best correlated with VO2max. The combination of 6MWT and grip strength significantly improved the association with VO2max.

Prediction for the maximum inspiratory pressure value from the thoracic expansion measurement in Indonesian healthy young adults.

BackgroundThe diaphragm is the primary muscle responsible for breathing. Weakness in the diaphragm will result in breathing difficulties. The micro-RPM (respiratory pressure meter) is a non-invasive testing device to measure respiratory muscle strength, which is not always feasible, while thoracic expansion measurements are easy to do.AimThis study constructs a prediction formula for a maximal inspiratory pressure (MIP) value from thoracic expansion measurements.MethodsThis study was quantitative with a cross-sectional design. Participants were healthy adults aged 20–40 years, with normal Mini-Mental State Examinations, body mass index, spirometry, and moderate activity levels. The tests performed were MIP and thoracic expansion measurements at three levels: axilla (L1), the fourth intercostal space (L2), and at processus xiphoideus (L3). The data were analyzed using an unpaired t-test and multivariate.ResultsThe mean MIP for males (81.51 ± 13.90 cmH2O) was significantly greater than females (63.17 ± 15.89 cmH2O) (P = 0.0001). These findings were not different with the Chinese, Indian, Mangalorean, and Malaysian populations because they are all of Asian ethnicity. Thoracic expansion L2 (r = 0.463, P = 0.0001) and L3 (r = 0.502, P = 0.0001) were moderately correlated with MIP, whereas thoracic expansion L2, L3 combined with gender had a weak effect on MIP. The prediction formula was: MIP = 56.802 + 2.387 + L2 + 13.904 + Gender * and MIP = 53.289+ 3.561 + L3 + 9.504 + Gender *, * 0 = female; 1 = male.ConclusionsA prediction formula for MIP can be made using the thoracic expansion variable with gender as a determinant factor. A quick and easy measurement of thoracic expansion can be used as a mean of screening respiratory muscle strength in patient care.

Abstract 13927: Sustained Maximal Inspiratory Pressure: A Novel Measure of Inspiratory Muscle Performance and Its Relationship to Physiology and Function in Heart Failure

Introduction: The sustained maximal inspiratory pressure (SMIP) is a novel measure of inspiratory muscle performance that reflects the ability of the inspiratory muscles to maintain force over time from residual volume (RV) to total lung capacity (TLC) and has been described as single-breath work capacity. In chronic obstructive pulmonary disease SMIP has been found to be more highly correlated to a greater number of physiologic and functional measures than maximal inspiratory pressure (MIP). This study examined the relationship of SMIP and MIP to a variety of physiologic and functional measures in patients with heart failure (HF). Methods: Fifty male Veterans (mean±SD age, BMI, LVEF = 69.9±8.0 years, 33.6±7.2 kg/m 2 , 40.1±14.4%, respectively) with HF underwent measurement of MIP and SMIP with the PrO2 device (Smithfield, RI) which were measured from RV during initial inhalation and to TLC, respectively. Pulmonary function and maximal expiratory pressure (MEP) were also assessed. Exercise capacity was assessed via cardiopulmonary exercise testing (CPET) and leg strength testing. Physical function was assessed with grip strength, 6-minute walk distance (6MWD), and sit-to-stand test (STS). Results: The mean±SD MIP and SMIP were 66.3±24.8 cmH 2 O and 351.3±151.4 PTU, respectively. Both MIP and SMIP were significantly (p&lt;0.05) correlated to many physiologic (r=.33-.48) and functional measures (r=.38-.62) with the greatest correlate to MIP being MEP (r=.58) and the greatest correlate to SMIP being FEV 1 (r=.62). The greatest physiologic correlate to MIP and SMIP was CPET peak tidal volume with identical r-values (.48). Absolute and relative peak oxygen consumption (pVO 2 ) were correlated to both MIP and SMIP with identical r-values for absolute pVO 2 (.33) and slightly higher r-values between MIP and relative pVO 2 (.37 vs .34). The greatest functional correlate to MIP and SMIP was leg strength/endurance (r=.53 and .46, respectively) followed by STS (r=.52 and .45, respectively) and 6MWD (r=.49 and .45, respectively). Conclusions: MIP and SMIP are significantly correlated in a positive direction to many physiologic and functional measures supporting the role of inspiratory muscle training and further study of SMIP and MIP in HF.

Effect of postoperative high load long duration inspiratory muscle training on pulmonary function and functional capacity after mitral valve replacement surgery: A randomized controlled trial with follow-up.

ObjectivesAlthough, pre-operative inspiratory muscle training has been investigated and reported to be an effective strategy to reduce postoperative pulmonary complications, the efficacy of postoperative inspiratory muscle training as well as the proper load, frequency, and duration necessary to reduce the postoperative pulmonary complications has not been fully investigated. This study was designed to investigate the effect of postoperative high-load long-duration inspiratory muscle training on pulmonary function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.DesignProspective randomized controlled trial.MethodsA total of one hundred patients (mean age 38.3±3.29years) underwent mitral valve replacement surgery were randomized into experimental (n = 50) and control (n = 50) groups. The control group received conventional physiotherapy care, while experimental group received conventional care in addition to inspiratory muscle training, with 40% of the baseline maximal inspiratory pressure targeting a load of 80% by the end of the 8 weeks intervention protocol. Inspiratory muscle training started on the patient’s first day in the inpatient ward. Lung functions, inspiratory muscle strength, and functional capacity were evaluated using a computer-based spirometry system, maximal inspiratory pressure measurement and 6MWT respectively at 5 time points and a follow-up assessment was performed 6 months after surgery. Repeated measure ANOVA and post-hoc analyses were used (p <0.05).ResultsGroup-time interactions were detected for all the studied variables (p<0.001). Between-group analysis revealed statistically significant postoperative improvements in all studied variables in the experimental group compared to the control group (p <0.001) with large effect size of η2 ˃0.14. Within-group analysis indicated substantial improvements in lung function, inspiratory pressure and functional capacity in the experimental group (p <0.05) over time, and these improvements were maintained at follow-up.ConclusionHigh intensity, long-duration postoperative inspiratory muscle training is highly effective in improving lung function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.

Reduced inspiratory muscle strength increases pneumonia in patients with acute myocardial infarction.

Inspiratory muscle strength is associated with pneumonia in patients after surgery or those with subacute stroke. However, inspiratory muscle strength in patients with acute myocardial infarction (AMI) has not been studied. To evaluate the predictive value of inspiratory muscle strength for pneumonia in patients with AMI. Patients with AMI were consecutively enrolled from March 2019 to September 2019. Measurements of maximal inspiratory pressure (MIP) were used to estimate inspiratory muscle strength and mostly were taken within 24 hr after culprit-vessel revascularization. Patients were divided into 3 groups by MIP tertile (T1: <56.1cm H2O, n=88; T2: 56.1-84.9cm H2O, n=88; T3: >84.9cm H2O, n=89). The primary endpoint was in-hospital pneumonia. Among 265 enrolled patients, pneumonia developed in 26 (10%). The rates of pneumonia were decreased from MIP T1 to T3 (T1: 17%, T2: 10%, T3: 2%, P=0.004). In-hospital all-cause mortality and major adverse cardiovascular events (MACEs) did not differ between groups. Multivariate logistic regression confirmed increased MIP associated with reduced risk of pneumonia (odds ratio 0.78, 95% confidence interval 0.65-0.94, P=0.008). Receiver operating characteristic curve analysis indicated that MIP had good performance for predicting in-hospital pneumonia, with an area under the curve of 0.72 (95% confidence interval 0.64-0.81, P<0.001). The risk of pneumonia but not in-hospital mortality and MACEs was increased in AMI patients with inspiratory muscle weakness. Future study focused on training inspiratory muscle may be helpful.

Differences in maximal inspiratory pressure when using a standard yoga mat versus a standard yoga block in healthy individuals

Background Yoga, which incorporates posture optimisation and specific breathing techniques, is recognised for its health benefits including musculoskeletal strengthening, stress relief and respiratory enhancement. It is therefore becoming an increasingly utilised practice within the medical environment, specifically for those with respiratory dysfunctions such as chronic obstructive pulmonary disease (COPD). The relationship between posture and yoga and the potential impact upon breathing is an important topic to study for its potential health benefits. This study compares the impact of two different yoga seating positions on respiratory muscle strength. Methodology Eighteen students from Cardiff University between the ages of 19–34 years were recruited via convenience sampling. Each was in good health, with body mass index (BMI) in the normal category and possessed no respiratory infection or significant spinal deformities. Participants were required to sit comfortably, cross-legged for 2 minutes in each sitting position, before three measurements of maximal inspiratory pressure (MIP) were taken. Analysis was performed on the highest result in each position using Statistical Package for the Social Sciences (SPSS) version 25. Comments on comfort levels were given spontaneously and, despite not being a primary aim of the study, provided an interesting discussion point. Results and conclusions Sitting on a yoga mat produced higher mean MIP figures (104cm H2O) than the yoga block (100.39cm H2O), p = 0.015. Despite statistical significance, the mean difference of 3.61cm H2O is unlikely to have clinical significance as it is small compared to the observed MIP range (&gt;90 cm H2O). There does not appear to be a recognised minimum clinically important difference in the literature, making interpretation difficult.

Composição corporal, função pulmonar e força muscular respiratória em pessoas com Síndrome de Down

Objetivo: investigar se há correlação nas variáveis da composição corporal com a função pulmonar e com a força muscular respiratória em pessoas com Síndrome de Down. Método: Analítico transversal, com 26 pessoas com Síndrome de Down, sendo 14 do sexo feminino e 12 do masculino. Foi realizada a espirometria para a obtenção do Volume Expirado Forçado no primeiro segundo (VEF1), Capacidade Vital Forçada (CVF) e Pico de Fluxo Expiratório (PFE); a manovacuometria para a mensuração da Pressão Inspiratória máxima (PImáx) e Pressão Expiratória máxima (PEmáx) e para a avaliação do percentual de gordura corporal (%GC) por meio da Dual Energy X-Ray Absormetry (DXA). Foi aplicado o teste de normalidade de Shapiro-Wilk, considerando p&lt;0,05 e o teste paramétrico por meio do coeficiente de correlação de Pearson. Resultados: Correlação negativa (%GC-VEF1), sem diferença significativa para os homens (p&lt;0,5244), com diferença altamente significativa para mulheres (p&lt;0,0045); % GC-CVF correlação negativa com diferença significativa (p&lt;0,0137) para mulheres, sem diferença significativa para homens (p&lt;0,4910); PFE correlação negativa, sem diferença significativa nas mulheres (p&lt;0,3165) e nos homens (p&lt;0,7165); %GC-PImáx correlação negativa para mulheres sem diferença significativa (p&lt;0,7871) e correlação positiva para os homens sem diferença significativa (p&lt;0,8307); %GC-PEmáx correlação negativa sem diferença significativa nas mulheres (p&lt;0,9070) e nos homens (p&lt;0,11369). Conclusão: Pessoas com Síndrome de Down apresentam %GC mais elevado frente aos valores de referência para a população brasileira sem a Síndrome de Down.

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.

The relationship between maximal expiratory pressure values and critical outcomes in mechanically ventilated patients: a post hoc analysis of an observational study

BackgroundLittle interest has been paid to expiratory muscle strength, and the impact of expiratory muscle weakness on critical outcomes is not known. Very few studies assessed the relationship between maximal expiratory pressure (MEP) and critical outcomes. The aim of this study was to investigate the relationship between MEP and critical outcomes.MethodsThis work was a secondary analysis of a prospective, observational study of adult patients who required mechanical ventilation for ≥ 24 h in an 18-bed ICU. MEP was assessed before extubation after a successful, spontaneous breathing trial. The relationships between MEP and extubation failure, and short-term (30 days) mortality, were investigated. Univariate logistic regressions were computed to investigate the relationship between MEP values and critical outcomes. Two multivariate analyses, with and without maximal inspiratory pressure (MIP), both adjusted using principal component analysis, were undertaken. Unadjusted and adjusted ROC curves were computed to compare the respective ability of MEP, MIP and the combination of both measures to discriminate patients with and without extubation failure or premature death.ResultsOne hundred and twenty-four patients were included. Median age was 66 years (IQR 18) and median mechanical ventilation duration was 7 days (IQR 6). Extubation failure rate was 15% (18/124 patients) and the rate for 30-day mortality was 11% (14/124 patient). Higher MEP values were significantly associated with a lower risk of extubation failure in the univariate analysis [OR 0.96 95% CI (0.93–0.98)], but not with short-term mortality. MEP was independently linked with extubation failure when MIP was not included in the multivariate model, but not when it was included, despite limited collinearity between these variables. This study was not able to differentiate the respective abilities of MEP, MIP, and their combination to discriminate patients with extubation failure or premature death (adjusted AUC for the combination of MEP and MIP: 0.825 and 0.650 for extubation failure and premature death, respectively).ConclusionsMEP is related to extubation failure. But, the results did not support its use as a substitute for MIP, since the relationship between MEP and critical outcomes was no longer significant when MIP was included. The use of MIP and MEP measurements combined did not reach higher discriminative capacities for critical outcomes that MEP or MIP alone.Trial Registration This study was retrospectively registered at https://clinicaltrials.gov/ct2/show/NCT02363231?cond=NCT02363231&draw=2&rank=1 (NCT02363231) in 13 February 2015

Inspiratory and Lower-Limb Strength Importance in Mountain Ultramarathon Running. Sex Differences and Relationship with Performance.

The study was aimed at comparing lower-limb strength and respiratory parameters between male and female athletes and their interaction with performance in a 107 km mountain ultramarathon. Forty seven runners (29 males and 18 females; mean ± SD age: 41 ± 5 years) were enrolled. Lower-limb strength assessment comprised a squat jump test, an ankle rebound test, and an isometric strength test. Respiratory assessment included pulmonary function testing and the measurement of maximal inspiratory pressure. Male athletes performed largely better in the squat jump (26 ± 4 vs. 21 ± 3 cm; p < 0.001; d = 1.48), while no sex differences were found in the other two lower-limb tests. Concerning the respiratory parameters, male athletes showed largely greater values in pulmonary expiratory variables: forced vital capacity (5.19 ± 0.68 vs. 3.65 ± 0.52 L; p < 0.001; d = 2.53), forced expiratory volume in 1 s (4.24 ± 0.54 vs. 2.97 ± 0.39 L; p < 0.001; d = 2.69), peak expiratory flow (9.9 ± 1.56 vs. 5.89 ± 1.39 L/min; p < 0.001; d = 2.77) and maximum voluntary ventilation in 12 s (171 ± 39 vs. 108 ± 23 L/min; p < 0.001; d = 1.93); while no sex differences were identified in maximal inspiratory pressure. Race time was associated with ankle rebound test performance (r = −0.390; p = 0.027), isometric strength test performance (r = −0.349; p = 0.049) and maximal inspiratory pressure (r = −0.544; p < 0.001). Consequently, it seems that athletes competing in mountain ultramarathons may benefit from improving lower-limb isometric strength, ankle reactive strength and inspiratory muscle strength. Nevertheless, further interventional studies are required to confirm these exploratory results. In addition, the fact that the magnitude of the sex difference for isometric strength was minor, as compared with the other strength tests, could represent one of the factors explaining why the performance gap between males and females is reduced in ultramarathons.

Effect of pranayama on respiratory muscle strength in chronic asthmatics

Background: Pranayama is a breathing technique that produces many systemic and psychological effects in the body, specifically on the respiratory system. It is also an art which controls the life force of breath. Aims and Objectives: The current study is designed to assess the effect of pranayama on respiratory muscle strength of chronic asthmatics. Materials and Methods: This study is designed to observe the measurement of maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) in asthma patients before and after Pranayama practice. Maximum respiratory pressure is one of the important methods of diagnosing respiratory muscle dysfunction. The study group consisted of 100 asthmatics. The participants were asked to undergo Pranayama training for 30 min daily, for 12 weeks. In the beginning of the course, the first phase of the recording was done and the second phase was done after 12 weeks of the regular pranayama practice. Result: The results showed statistically significant improvement in MIP from 64.08 ± 8.162 to 70.38 ± 6.169 and MEP from 107.92 ± 9.897 to 113.68 ± 8.767 in asthma patients after pranayama. Conclusion: The current study shows that pranayama has a positive effect on respiratory system with evidence of improvement in respiratory muscle strength.

Maximal Inspiratory Pressure: Does the Choice of Reference Values Actually Matter?

Single-point measurements of maximal inspiratory pressure (MIP) are frequently used to suggest muscle weakness in clinical practice. Although there is a large variability in "mean" predicted MIP depending on the chosen reference values, it remains unclear whether those discrepancies actually impact on the prevalence of weakness, that is, MIP below the lower limit of normal. A total of 1,729 subjects (50.1%men, aged 20 to 94 years) who underwent MIP measurements in a clinical laboratory comprised the study group. MIP was predicted according to the most frequently cited regression equations as of August 2015. Pretest probability of weakness was defined by a cluster of clinical and physiologic variables. Prevalence of weakness ranged from 33.4 to 66.9%. Set 2 equations agreed well in indicating weakness (κ [95%CI] ranging from 0.81 [0.79-0.83] to 0.83 [0.81-0.85]; P< .01). There was closer agreement between higher pretest probability of weakness and low MIP according to set 2 equations compared with set 1 equations. Thus, a significant fraction of subjects with abnormal MIP according to set 1 equations but preserved MIP according to set 2 equations had higher pretest probability of weakness (P< .05). The choice of MIP reference values strongly impacts on the prevalence of weakness. Some specific equations relate better to clinical and physiologic indicators of weakness, suggesting that they might be particularly useful to screen subjects for advanced respiratory neuromuscular assessment.

Preoperative maximal expiratory pressure is associated with duration of invasive mechanical ventilation after cardiac surgery: An observational study

ObjectiveTo evaluate the association of maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), and peak expiratory flow (PEF) with total duration of invasive mechanical ventilation (IMV) in subjects undergoing cardiac surgery. BackgroundProlonged IMV is associated with respiratory infections, prolonged hospitalization, and increased mortality. Pulmonary function tests can help predict postoperative outcomes after cardiac surgery. MethodsWe recruited subjects admitted for cardiac surgery. All MIP, MEP, and PEF measurements were performed before surgery. Multivariable analysis was performed using a multiple linear regression model to control for possible confounders and test for association of MIP, MEP, and PEF with IMV duration. ResultsOverall, 125 subjects were included in the study. Higher MEP was associated with reduced duration of IMV after adjustment for confounders (P = 0.015), but no such association was observed between MIP or PEF and IMV. ConclusionsIn subjects undergoing elective cardiac surgery, preoperative MEP is associated with IMV duration.