Maximum Static Expiratory Pressures Research Articles

Effects of Respiratory Muscle Training on Pulmonary Function in Individuals with Spinal Cord Injury: An Updated Meta-analysis.

Objective To investigate the pulmonary function responses to respiratory muscle training (RMT) in individuals with tetraplegia and provide a systematic review of the included studies. Methods Computerized retrieval of randomized controlled trials (RCT) in PubMed, Embase, and the Cochrane Library on the improvement of respiratory function in patients with spinal cord injury by RMT was conducted until May 2019. Two researchers independently screened the literature, extracted the data, and evaluated the risk of bias in the included studies. Articles were scored for their methodological quality using the Cochrane Collaboration risk of bias assessment tool. Results Sixteen studies were identified. A significant benefit of RMT was revealed for five outcomes: force vital capacity (FVC, WMD: -0.43, 95% CI -0.84 to -0.03, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, Conclusion Our findings demonstrate that RMT can effectively improve spinal cord injury pulmonary function of the patient, which is marked by increasing respiratory strength, function, and endurance. Limited by the quantity and quality of the included studies, the above conclusion needs to be verified by more high-quality studies.

Effects of Resistance Training of Peripheral Muscles Versus Respiratory Muscles in Older Adults With Sarcopenia Who are Institutionalized: A Randomized Controlled Trial.

This study compares the effects of two resistance training programs in peripheral and respiratory musculature on muscle mass and strength and physical performance and identifies the appropriate muscle mass parameter for assessing the intervention effects. Thirty-seven institutionalized older Spanish adults with sarcopenia were analyzed: control group (n = 17), respiratory muscle training group (n = 9), and peripheral muscle training group (n = 11). Measured outcomes were appendicular skeletal muscle mass (ASM/height2, ASM/weight, and ASM/BMI), isometric knee extension, arm flexion and handgrip strength, maximal inspiratory and expiratory pressures, and gait speed pre- and postintervention. Trained groups participated in a 12-week program and improved in maximum static inspiratory pressure, maximum static expiratory pressure, knee extension, and arm flexion (p < .05), whereas nonsignificant changes were found in gait speed and ASM indexes pre- and postintervention in the three groups. In conclusion, resistance training improved skeletal muscle strength in the studied population, and any ASM index was found to be appropriate for detecting changes after physical interventions.

MAXIMAL RESPIRATORY PRESSURES AND THEIR CORRELATES IN NORMAL INDIAN ADULT POPULATION: A CROSS-SECTIONAL STUDY

Background: The measurement of maximum static inspiratory pressure (MIP) and maximum static expiratory pressure (MEP) is important in the diagnosis of respiratory muscle dysfunction. There is a paucity of data done on MIP and MEP across the decades in Indian population to predict normal values for maximal respiratory pressures. Materials and Methods: Five hundred subjects were selected through purposive sampling. Each age group had 100 subjects (50 males and 50 females). Pulmonary function tests and baseline data of demographic and anthropometric data of the normal subjects like age, height, weight and body mass index was recorded. The maximal inspiratory pressure (MIP) and Maximal expiratory pressure (MEP) was measured with a portable respiratory pressure meter (Micro RPM) using a standard protocol. Results: MIP and MEP were studied across all decades and the mean values obtained were comparable with that of the Caucasian population in previous studies. Also MIP and MEP mean values were significantly higher in males as compared to females across the decades. Age showed a statistically significant negative correlation with both MIP and MEP with pearsons correlation coefficient. In males, MIP and MEP correlated negatively with height and weight. In females MIP correlated negatively with height and MEP correlated positively with height and weight. Conclusion: The decade wise mean values obtained for MIP and MEP can be used as a reference to determine respiratory muscle strength in normal Indian adult population.

Muscle impairment in neuromuscular disease using an expiratory/inspiratory pressure ratio.

Neuromuscular diseases (NMDs) lead to different weakness patterns, and most patients with NMDs develop respiratory failure. Inspiratory and expiratory muscle strength can be measured by maximum static inspiratory pressure (PImax) and maximum static expiratory pressure (PEmax), and the relationship between them has not been well described in healthy subjects and subjects with NMDs. Our aim was to assess expiratory/inspiratory muscle strength in NMDs and healthy subjects and calculate PEmax/PImax ratio for these groups. Seventy (35 males) subjects with NMDs (amyotrophic lateral sclerosis, myasthenia gravis, and myotonic dystrophy), and 93 (47 males) healthy individuals 20-80 y of age were evaluated for anthropometry, pulmonary function, PImax, and PEmax, respectively. Healthy individuals showed greater values for PImax and PEmax when compared with subjects with NMDs. PEmax/PImax ratio for healthy subjects was 1.31 ± 0.26, and PEmax%/PImax% was 1.04 ± 0.05; for subjects with NMDs, PEmax/PImax ratio was 1.45 ± 0.65, and PEmax%/PImax% ratio was 1.42 ± 0.67. We found that PEmax%/PImax% for myotonic dystrophy was 0.93 ± 0.24, for myasthenia gravis 1.94 ± 0.6, and for amyotrophic lateral sclerosis 1.33 ± 0.62 when we analyzed them separately. All healthy individuals showed higher PEmax compared with PImax. For subjects with NMDs, the impairment of PEmax and PImax is different among the 3 pathologies studied (P < .001). Healthy individuals and subjects with NMDs showed higher PEmax in comparison to PImax regarding the PEmax/PImax ratio. Based on the ratio, it is possible to state that NMDs show different patterns of respiratory muscle strength loss. PEmax/PImax ratio is a useful parameter to assess the impairment of respiratory muscles in a patient and to customize rehabilitation and treatment.

Inspiratory muscle weakness is associated with autonomic cardiovascular dysfunction in patients with type 2 diabetes mellitus

Diabetic autonomic neuropathy is a complication of diabetes mellitus (DM) that can cause cardiovascular and respiratory abnormalities. The association between respiratory muscle weakness and autonomic cardiovascular neuropathy has not yet been studied. The aims of the present study were to assess respiratory muscle strength, pulmonary function, and heart rate (HR) variability in diabetic patients with and without diabetic autonomic neuropathy. Twenty-four patients with type 2 DM were divided into two groups: those without diabetic autonomic neuropathy (C group, n=12); and those with diabetic autonomic neuropathy (DAN group, n=12). We evaluated pulmonary function, maximum static inspiratory pressure (PImax), maximum static expiratory pressure (PEmax), and HR variability. The results of the pulmonary function tests were similar in both the groups. PImax was lower in the DAN group (80±24 vs. 102±24cmH(2)O, p=0.03), but PEmax was similar in both the groups. RR intervals (878±122 vs. 743±88ms; p<0.01), standard deviation of RR intervals (28±11 vs. 14±4ms; p<0.01) and squared root of the sum of successive differences of squared RR intervals (15±6 vs. 8±5ms; p<0.01) were higher in the C group. In the DAN group, resting HR was higher (82±10 vs. 69±9bpm; p=0.01) than in the C group. There was a positive correlation between PImax and RR intervals (r=0.452, p=0.02) and a negative correlation between PImax and resting HR (r=-0.482, p=0.01), and PImax and DM duration (r=-0.463, p=0.02). Patients with type 2 DM and autonomic neuropathy showed reduced respiratory muscle strength and less HR variability. Respiratory muscle weakness may be associated with autonomic dysfunction in these patients.

Transcranial magnetic stimulation study of expiratory muscle weakness in acute ischemic stroke

Expiratory muscle weakness due to cerebral infarction may contribute to reduced airway clearance in stroke patients. Transcranial magnetic stimulation (TMS) at the vertex and over each hemisphere and magnetic stimulation over the T(10-11) spinal roots (Tw T(10)) and the phrenic nerves bilaterally (BAMPS) were performed in 15 acute ischemic stroke patients (age 68.9 +/- 9.8 years) and 16 matched controls. Surface electrodes recorded motor evoked potentials (MEPs) in the rectus abdominis (RA) and external oblique (EO) muscles bilaterally. Respiratory muscle function was assessed by measuring maximum static expiratory pressure (PE(max)) and changes in intragastric (P(gas)) and transdiaphragmatic (P(di)) pressure after voluntary cough, TMS, TwT(10), and BAMPS. Regression models were used to assess determinants of peak voluntary cough flow rates (PCFR). PCFR, cough P(gas), and vertex TMS P(gas) were decreased in stroke patients compared with controls (203.6 +/- 151.1 vs 350.8 +/- 111.7 L/min, p = 0.004; 72.7 +/- 64.5 vs 163.4 +/- 55.8 cm H(2)O, p = 0.0003 and 8.7 +/- 3.3 vs 16.7 +/- 11.5 cm H(2)O, p = 0.023, respectively). There were no differences in TwT(10) P(gas) (25.2 +/- 7.8 vs 29.4 +/- 12.4 cm H(2)O, p = 0.153) or BAMPS P(di) (21.6 +/- 7.2 vs 19.2 +/- 3.4 cm H(2)O, p = 0.163). TMS P(gas) was lower (4.1 +/- 2.8 vs 6.1 +/- 1.9 cm H(2)O, p = 0.023) following TMS of the injured compared with the uninjured hemisphere in stroke patients. Age and gender adjusted PCFR correlated with P(gas) (r = 0.51, p = 0.009) and PE(max) (r = 0.46, p = 0.024). Stroke was an independent determinant of PCFR after adjusting for P(gas) and PE(max) (p = 0.031). Ischemic cortical injury is associated with expiratory muscle weakness and may contribute to cough impairment in stroke patients.

Regression simulation of the dependence of forced expiratory tracheal noises duration on human respiratory system biomechanical parameters

Background Estimating the duration of forced exhalation tracheal noises shows promise for recognizing bronchial obstruction. Objective Experimental simulation of an influence of biomechanical parameters on the duration of normal forced exhalation tracheal noises. Method and materials Thirty-two healthy non-smoking men aged 16–22 years were examined. The duration of noises, the parameters of computer spirometry, and the maximum static expiratory pressure are recorded. These data were analyzed by means of multiple linear regression simulation for logarithms of the elements of the proportionality relation obtained with the use of a one-component biomechanical model of forced exhalation and a linearized approximation of flow–volume curve. Results Dependence between duration of the forced expiratory noises recorded on human trachea and the product of forced volume capacity (in power of 1.05±0.27), maximum static expiratory pressure (in power of 0.46±0.23), equivalent expiratory resistance in the stage of functional expiratory stenosis (in power of 0.72±0.15) is established. Determination coefficient is 0.57. The duration of forced expiratory noises recorded on human trachea in healthy is an estimate of the equivalent expiratory resistance of human bronchial tree in the functional expiratory stenosis phase, whereas in patients with bronchial obstruction it is supposed to take into account an excess of noise generation time compared with the time predicted from normal individual value of this resistance.

Respiratory muscle strength training with nonrespiratory maneuvers.

The diaphragm and abdominal muscles can be recruited during nonrespiratory maneuvers. With these maneuvers, transdiaphragmatic pressures are elevated to levels that could potentially provide a strength-training stimulus. To determine whether repeated forceful nonrespiratory maneuvers strengthen the diaphragm, four healthy subjects performed sit-ups and biceps curls 3-4 days/wk for 16 wk and four subjects served as controls. The maximal transdiaphragmatic pressure was measured at baseline and after 16 wk of training. Maximum static inspiratory and expiratory mouth pressures and diaphragm thickness derived from ultrasound were measured at baseline and 8 and 16 wk. After training, there were significant increases in diaphragm thickness [2.5 +/- 0.1 to 3.2 +/- 0.1 mm (mean +/- SD) (P < 0.001)], maximal transdiaphragmatic pressure [198 +/- 21 to 256 +/- 23 cmH2O (P < 0.02)], maximum static inspiratory pressure [134 +/- 22 to 171 +/- 16 cmH2O (P < 0.002)], maximum static expiratory pressure [195 +/- 20 to 267 +/- 40 cmH2O (P < 0.002)], and maximum gastric pressure [161 +/- 5 to 212 +/- 40 cmH2O (P < 0.03)]. These parameters were unchanged in the control group. We conclude that nonrespiratory maneuvers can strengthen the inspiratory and expiratory muscles in healthy individuals. Because diaphragm thickness increased with training, the increase in maximal pressures is unlikely due to a learning effect.

Pulmonary function and respiratory muscle strength in chronic heart failure: comparison between ischaemic and idiopathic dilated cardiomyopathy

OBJECTIVETo compare pulmonary function and respiratory muscle strength in patients with ischaemic and idiopathic dilated cardiomyopathy, well matched for indices of heart failure.METHODSThe study involved 30 patients with ischaemic cardiomyopathy...

Influence of Age on Diurnal Variability in Measurements of Spirometric Indices and Respiratory Pressures

We evaluated variations in spirometric indices (i.e., forced vital capacity [FVC], peak expiratory flow [PEF], and forced expiratory volume in 1 sec [FEV,1]) and static respiratory muscle pressures (i.e., maximum static inspiratory pressure [PImax] and maximum static expiratory pressure [PEmax]) within a span of 12 hr in 60 healthy elderly subjects, 60 young subjects, and 30 Chronic Obstructive Pulmonary disease (COPD) patients. There were no differences among data of FVC, PEF, FEV1, Plmax, and PEmax on three separate occasions within a day in the elderly or the young. The mean coefficient of variation (CV) values of PEF and Plmax on three occasions were 3.0 ± 0.3% and 4.2 ± 0.4% in the elderly, and 2.4 ± 0.2% and 3.7 ± 0.3% in the young, respectively. No subjects had more than 9% CV on each measurement in the study, suggesting that there is no significant daytime variation in measurement of expiratory flow and respiratory pressures in young and elderly people. However, FVC, PEF FEV1, and Plmax values in the morning were smaller than those measured at the other two occasions in COPD patients. The results indicate that COPD affects diurnal variation in pulmonary function, but age alone has little impact on diurnal variation.

Measurement of maximal expiratory pressure: effect of holding the lips.

Minor differences in technique may account for the wide range of published normal values of maximum expiratory and inspiratory pressures. The effects of holding the lips while the subject performed a maximal expiratory pressure manoeuvre were investigated in this study. Maximum static expiratory pressures (PEmax) obtained with a cylindrical tube by means of lip compression by the subject and technician aided compression were compared in 20 men (mean age 27 years) and 20 women (mean age 28 years). Technician aided lip compression was associated with higher maximum expiratory pressure than compression by the subject in both men (195 v 110 cm H2O) and women (134 v 80 cm H2O). Compression of the lips and corners of the mouth should be performed by a trained technician for maximum expiratory pressure measurements when a cylindrical mouthpiece is used.

The effect of posture on ventilatory muscle function and lung function

The purpose of this study was to determine the influence of posture on ventilatory muscle strength and on lung function.Maximum static inspiratory pressures (MIPS), maximum static expiratory pressures (MEPS) and lung function measurements (FVC, FEV1, PEFR) were obtained in three different body positions in 57 normal subjects and in 16 asthmatic patients.Statistical analysis of the data obtained showed that changes in position influence the ventilatory muscle function and lung function values.The sitting lean forward and the sitting erect positions were the better positions in the normal group. The findings revealed that the sitting lean forward position was the optimum position for the asthmatic group (p 0,001).