Maximal Static Respiratory Pressures Research Articles

Normative Data of Maximal Respiratory Pressures in Adult Population of the Himalayan Region: A Cross-sectional Study

Introduction: Measurement of Maximal Static Respiratory Pressures (MSRP) is a non invasive tool to determine global respiratory muscle strength. The unique lifestyle factors in the Himalayan region, prompted the need for establishing normative values. Aim: To establish the typical maximum respiratory pressures in the Himalayan region and, secondarily, to develop a predictive equation based on the normative data collected. Materials and Methods: A cross-sectional observational study was conducted at the Department of Respiratory Medicine, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, Uttarakhand, India. A total of 101 non smokers (78 males, 23 females) aged from 19-70 years were selected after initial screening by a questionnaire and spirometry from the attendants of patients attending Himalayan Hospital from July 2000 to May 2022. Sustained Nasal Inspiratory Pressure (SNIP), Maximal Expiratory Pressure (MEP), and Maximal Inspiratory Pressure (MIP) values were measured using Micro Respiratory Pressure Meter (RPM) following the American Thoracic Society Technical Statement (ATS) standard protocol. The prediction model for the Maximal Respiratory Pressure (MRP) was obtained using regression analysis. Height, age, weight, and Body Mass Index (BMI) were included as variables in the calculations. The statistical analysis was conducted using the Statistical Package for Social Sciences (SPSS) program for Windows (Version 22.0). Results: There was a statistically significant difference observed in MIP among males 91.77±29.41 cmH2 O and females 65.26±19.55 cmH2 O and in MEP among males 86.37±26.96 cmH2 O and females 56.04±18.29 cmH2 O. Both MIP and MEP averages were more in males than in females. In the present study, there was no significant relationship between height, weight, BMI, and respiratory pressure in females. There was no significant relationship between MIP and MEP plus height, age, weight, or BMI. Weight (r-value=0.24), age (r-value=0.27), and BMI (r-value=0.27) all had a significant association in men. Conclusion: Based on these findings, it can be concluded that there are gender-based disparities in MRP in the Himalayan population, with males exhibiting higher average values than females. Additionally, while there was no significant correlation between anthropometric factors and respiratory pressures in females, in males, weight, age, and BMI showed significant associations with these respiratory parameters.

Study of relation between maximal static respiratory pressures and pulmonary functions in patients of bronchial asthma

Study of relation between maximal static respiratory pressures and pulmonary functions in patients of bronchial asthma

Maximal Static Respiratory and Sniff Pressures in Healthy Children. A Systematic Review and Meta-Analysis.

Respiratory muscle strength in children can be assessed by maximal inspiratory pressures (MIP), maximal expiratory pressures (MEP), and sniff nasal inspiratory pressures (SNIP). However, previous studies involved small cohorts of healthy children and reported wide reference ranges. To perform a systematic review to summarize existing reference ranges for MIP, MEP, and SNIP tests in healthy children and to conduct a meta-analysis to develop comprehensive prediction equations. Five databases were searched for relevant studies from database inception to May 29, 2017. Study inclusion was limited to publications that evaluated MIP, MEP, and SNIP values in healthy children aged 18 years or younger. Studies were also excluded if testing methodology differed greatly from the 2002 American Thoracic Society Statement on Respiratory Muscle Testing. Requests for raw data were made to authors via e-mail. A total of 18 studies including 3,509 children were systematically reviewed. Diagnostic accuracy of the included studies was assessed using the QUADAS-2 tool, which revealed a high risk of bias for flow and timing and for applicability that may influence the generalizability of our findings. All 18 studies evaluated respiratory pressures in children in seated position. MIP tests were conducted from residual volume, MEP tests from total lung capacity, and SNIP tests from functional residual capacity. The MIP and MEP values in three age groups for boys and girls were summarized using meta-analysis based on individual participant data from five studies containing 1,709 healthy children. Further analyses showed that MIP and MEP were significantly greater in boys than in girls (P < 0.0001). In both sexes, MEP values were always greater than MIP values (P < 0.05). Multivariable random effects models were then performed to establish sex-specific prediction equations. These equations found age, height, and weight to be significant predictor variables. Only two studies with SNIP values from healthy children were included in the review, but they were not part of the meta-analysis. We summarized the available reference ranges for MIP, MEP, and SNIP tests based on existing literature, especially for three age groups, and developed prediction equations that can be used in pulmonary function laboratories to aid clinicians. Existing literature on SNIP tests is limited, and future studies are encouraged to explore their use in children. Systematic review registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42017072004).

Myelodysplastic syndrome patients present more severe respiratory muscle impairment and reduced forced vital capacity: Is disordered inflammatory signaling the culprit?

Background/ObjectivesThe ageing process is associated with gradual decline in respiratory system performance. Anemia is highly prevalent among older adults and usually associated with adverse outcomes. Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic malignancies with increasing incidence with age and characterized by anemia and other cytopenias. The main objectives of this study were to evaluate respiratory muscle strength and lung function in elderly patients with anemia, compare data between myelodysplastic syndromes and non-clonal anemias and evaluate the influence of serum IL-8 level and NF-kB activity on deteriorate pulmonary function in this specific population.ParticipantsIndividuals aged 60 and older with anemia secondary to MDS, non-clonal anemia and healthy elderly individuals.MeasurementsForced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/ FVC ratio were measured by spirometry. Respiratory muscle strength was evaluated by maximal static respiratory pressures measurement. IL-8 analysis was performed by ELISA and activity of NF-kB by chemiluminescent assay.ResultsMean Hb concentration was comparable between patients with anemia. Significant differences were detected between all patients with anemia and controls for maximum-effort inspiratory mouth pressure (PImax) and also for maximum-effort expiratory mouth pressure (PEmax). The MDS group recorded a significantly lower PImax and PEmax percent predicted when compared to non-clonal anemia group. For FVC and FEV1, a significant difference was found in anemic patients, with even significantly lower values for FVC and FEV1 in MDS group. No significant differences were detected for PImax and PEmax and spirometry parameters when anemic patients were stratified according to the degree of anemia. A significant negative impact in FVC (% pred), PImax (% pred) and PEmax (% pred) was observed in patients with MDS and higher levels of IL-8 or increased activity of NF-kB.ConclusionA negative impact of anemia, independent of its degree, was demonstrated in respiratory muscle strength and lung function particularly in MDS. The well known elevated proinflammatory cytokines in MDS patients were proposed to play a role as was demonstrated by detrimental effect of higher IL-8 and NF-kB in pulmonary function tests in this population.

Evaluation of functional capacity, body composicion and pulmonary function after bariatric surgery

Introduction: Obesity has been considered a global epidemic and a serious public health problem closely related to other diseases. Moreover, obese individuals have limitations in physical capacity and pulmonary function. Weight loss induced by bariatric surgery appears to help reverse this situation. However, questions about physical capacity and lung function, and its relationship with body composition remain to be clarified. Objective: To evaluate the physical capacity, body composition and lung function in women undergoing bariatric surgery. Methods: Twenty five women who underwent bariatric surgery between 6 and 24 months ago, and 10 non-obese women were evaluated for exercise capacity by the six minutes walk test (6 MWT), body composition by bio-electrical impedance analysis and lung function by spirometry and measurement of maximal static respiratory pressures. Results: Subjects with BMI 2 were found to have better physical performance, demonstrated by increased 6 MWT distance, not differing from non-obese women. When compared with non-obese women, there were no significant differences in body composition and lung function. Higher BMI was correlated with shorter distances in 6 MWT. Conclusion: 6 to 24 months after surgery, when the weight loss of patients who underwent bariatric surgery reaches levels considered non-obese, it provides improvement in physical performance to a level similar to that of non-obese patients.

Predicted preoperative maximal static respiratory pressures in adult cardiac surgeries: evaluation of two formulas

Cardiac surgery (CC) determines systemic and pulmonary changes that require special care. Awareness of the importance of respiratory muscle dysfunction in the development of respiratory failure motivated several studies conducted in healthy subjects to assess muscle strength. These studies were carried out by evaluating the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) values. This study examined the concordance among the values predicted by the equations proposed by Black & Hyatt and Neder, and the measured values in cardiac surgery (CS) patients. Data were collected from preoperative evaluation forms. The Lin coefficient and Bland-Altman plots were used for statistical concordance analysis. The multiple linear regression and analysis of variance (ANOVA) were used to produce new formulas. There were weak correlations of 0.22 and 0.19 in the MIP analysis and of 0.10 and 0.32 in the MEP analysis, for the formulas of Black & Hyatt and Neder, respectively. The ANOVA for both MIP and MEP were significant (P <0.0001), and the following formulas were developed: MIP = 88.82 - (0.51 x age) + (19.86 x gender), and MEP = 91.36 - (0.30 x age) + (29.92 x gender). The Black and Hyatt and Neder formulas predict highly discrepant values of MIP and MEP and should not be used to identify muscle weakness in CS patients.

Força muscular respiratória de mulheres obesas mórbidas e eutróficas

A obesidade mórbida é uma condição clínica que afeta a capacidade funcional, sendo a musculatura respiratória igualmente comprometida. Objetivou-se avaliar a força muscular inspiratória e expiratória de mulheres obesas mórbidas (MO) e eutróficas (ME). Estudo transversal com amostra composta por 21 mulheres (14 MO e 7 ME), pareadas pela idade e altura. A avaliação da força muscular inspiratória e expiratória foi realizada por meio da verificação das pressões inspiratória e expiratória por manovacuometria. Quando comparadas as pressões respiratórias estáticas máximas obtidas com os valores preditos para ME e MO, constata-se que as do primeiro grupo apresentam valores de P Imáx=119,14±1,9 cmH2O (152% do predito) e P Emáx=141,1±10,2 cmH2O (98,5% do predito) dentro dos limites de normalidade ou acima, enquanto no grupo de obesas mórbidas os valores de P Imáx=66±18,7 cmH2O (84,3% do predito) e P Emáx=78,4±14,2 cmH2O (54,3% do predito) foram inferiores aos preditos. Comparando-se as pressões respiratórias estáticas máximas obtidas de MO com ME, observa-se diferença significativa tanto para os valores de P Imáx (66±18,7 versus 119±1,9 cmH2O) como P Emáx (78,4±14,2 versus 141,14±10,20) com significância estatística de 0,001. Conclui-se que a força muscular respiratória é marcadamente diminuída em MO, quando comparadas a ME.

Respiratory muscle strength in adolescents with idiopathic scoliosis

Methods Vital capacity (VC) was measured using Jaeger's spirometer and values were compared to Zapletal's recommendations [2]. Maximal static respiratory pressures including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), were measured according to W. Tomalak's recommendations for Polish children [3]. Measurements were made using a portable, digital pressure meter equipped with the Omega PX25 pressure transducer (ZETA product – model MMM2).

Maximal static mouth respiratory pressure in spinal cord injured patients: correlation with motor level

Transversal. The few studies concerning maximal static mouth respiratory pressures in patients with spinal cord lesions suggest a marked reduction. We studied the correlation of these parameters with the motor level of injury. Rehabilitation Center, Brasília/DF, Brazil. One hundred and thirty-one patients with traumatic spinal cord injury (C4-L3) were recruited. The participants were assessed by standard spirometry and maximal static mouth respiratory pressure. Forced vital capacity was most reduced in tetraplegics (subgroup C4-C5, 49%+/-25 predicted) and increase successively for each descending subgroup (C6-C8, 61%+/-22 predicted; T1-T6, 70%+/-15 predicted), becoming normal in low paraplegia (T7-L3, 84%+/-15 predicted). There is no evidence of an obstructive disturbance throughout all groups. The lowest average percent predicted of maximal static inspiratory pressure (MIP) was in the subgroup C4-C5 (50%+/-23). The average percent predicted of maximal static expiratory pressure (MEP) improved from 19%+/-14 in the C4-C5 subgroup to 51%+/-19 for T7-L3 subgroup. The average percent predicted of all participants for MIP was 74%+/-30 and for MEP was 37%+/-21. In patients with complete motor lesion, the correlation with the level of injury was stronger for MEP (r=0.81, P<0.0001; r (2)=0.65) than for MIP (r=0.62, P=0.004; r (2)=0.38). No correlation was found among incomplete motor lesion patients. The linear regression equations for the relationship of percent predicted MIP or MEP to level of injury are applicable only to complete motor lesions and may be useful to establish normative association between them.

Maximal static respiratory pressures in children and adolescents.

This study was designed to establish reference values of maximal static respiratory pressures in children and adolescents in our community, and compare them with previous studies. Participants were recruited from three schools (randomly chosen from those located in the metropolitan area of the city of Valencia) after appropriate consent. None of the participants had a previous history of pulmonary, cardiac, and/or skeletal abnormalities, and all of them had normal spirometry. Forced spirometry (Spirotrac III, Vitalograph) and maximal inspiratory (P(ImaxRV)) and expiratory (P(EmaxTLC)) pressure values (Sibelmed 163) were obtained by the same investigator, following national guidelines (SEPAR 1990).We studied 392 subjects (185 males, 207 females) whose ages ranged from 8-17 years. The reproducibility of measurements was investigated in a subgroup of 88 participants (randomly selected from the total sample, and stratified for age and gender) by means of the intraclass correlation coefficient (P(EmaxTLC), 0.98; P(ImaxRV), 0.95). P(EmaxTLC) and P(ImaxRV) values were significantly different between males and females (P < 0.0001) and were normally distributed. A stepwise, linear multiple regression model was built in each gender group (male/female) for the prediction of P(ImaxRV) and P(EmaxTLC) values. Independent variables (weight, height, and age) and their potential interactions were forced to enter the model in order to maximize the square of the multiple correlation coefficient of the resultant equation. This model turned out to be applicable (homoscedasticity, independence, and normality requirements) for P(ImaxRV) (in males and females) and for P(EmaxTLC) (in males but not in females). Variables included in the model were age and the product of weight and height. Their predictive power ranged between 0.21-0.51. In conclusion, P(ImaxRV) and P(EmaxTLC) values increase with age from 8 until 17 years. In all age groups, values were higher in males than in females. Weight, height, and age are included in the predictive equations for P(ImaxRV) (in males and females) and P(EmaxTLC) (in males). Their predictive value is similar to that reported by other authors and ranges between 0.21-0.51. This model is not suitable for the prediction of P(EmaxTLC) in females; the observed mean and range should be used instead.

Normal values for maximal static inspiratory and expiratory pressures in healthy children.

Maximal static respiratory pressures are a simple measure of respiratory muscle strength. In order to construct a set of equations describing normal values, we measured maximal inspiratory (P(Imax)) and expiratory (P(Emax)) pressures in 296 children (144 boys and 152 girls), aged 7-14 years, in sitting and standing positions. The boys reached higher values in sitting and standing positions for P(Imax) (-8.29 +/- 2.69 and -8.19 +/- 2.73 kPa, respectively) and P(Emax) (8.02 +/- 2.32 and 7.94 +/- 2.32 kPa, respectively) than girls (-6.53 +/- 1.99 and -6.60 +/- 2.03 kPa for P(Imax) and 6.91 +/- 1.79 and 7.13 +/- 1.81 kPa for P(Emax) for sitting and standing positions, respectively); the differences between boys and girls were highly significant (P < 0.001 in all instances). There were no differences regarding body position during measurements in both genders. Multiple correlation analysis showed significant correlations of pressures to age in boys in all cases, but in girls only for P(Imax) in standing position. Therefore, equations describing reference values were constructed with respect to age as the independent variable. Maximal pressures also correlated with maximal inspiratory and expiratory flows. The measurements of P(Imax) and P(Emax) are useful in assessing respiratory muscle strength despite their relatively large variability. P(Imax) and P(Emax) also correlate with maximum peak expiratory and inspiratory flows. Children generate lower pressures and lower maximal flows than adolescents and adults.

Measurement of Maximal Static Respiratory Pressures at the Mouth with Different Air Leaks

The effect of two different circuit leaks on the measurement of maximal static inspiratory and expiratory pressures at the mouth (Pimax, Pemax) was assessed in 70 patients with respiratory disease. Patients were divided into three groups with similar anthropometric and spirometric characteristics. The first group (30 patients) had their Pmax measured with a leak of 2.0 mm internal diameter (ID) and 37 mm length (as proposed by T. Ringqvist) and repeated with a second leak of 1.0 mm ID and 15 mm length (as recommended by J. L. Clausen). The two measurements were done in random order. Measurements for the other two groups (20 patients each) were taken with one or another, the two leaks randomly alternated with no leak. Pimax measurements obtained with Ringqvist's leak were 17 percent (p less than 0.005) lower than those with Clausen's leak and 22 percent (p less than 0.005) lower than those with no leak. Pemax measurements performed with Ringqvist's leak in place were 11 percent (p less than 0.005) lower than those with Clausen's leak and 11 percent (p less than 0.005) lower than those obtained with no leak. The comparison between Clausen's leak and no leak showed no statistically significant difference. We conclude that whenever the effect of pressure generated in the mouth is to be avoided in the measurement of respiratory Pmax, a leak of the size proposed by Ringqvist is to be preferred.

Maximal static respiratory pressures in the normal elderly.

To determine if a relationship exists between maximal static respiratory pressures measured at the mouth and age greater than 55 yr, and if so, whether regression equations can be derived that accurately reflect this, we measured maximal inspiratory (Plmax) and expiratory (PEmax) pressures in 64 normal women and 40 normal men older than 55 yr of age. We found no relationship between PImax and PEmax and age greater than 55 yr (all r squared values less than 0.14). We tested the reproducibility of our measurements of PImax and PEmax in 13 and 12 subjects, respectively, on three separate occasions. Repeated measures analysis showed no significant differences in these measurements. Using the measurements obtained in this large study, we calculated 95% confidence limits for PImax and PEmax values in men and women older than 55 yr of age. The 95% confidence limits for PImax in men were 55 to 161 cm H2O, and 26 to 124 cm H2O in women. The 95% confidence limits for PEmax in men were 90 to 256 cm H2O, and 46 to 184 cm H2O in women. We conclude that given the large interindividual variation, a cross-sectional study such as this or other previous studies may not be able to reveal age-dependent changes unless very large numbers are used, and even then potential for bias exists. However, with the small intraindividual coefficients of variation in repeated measurements of PImax and PEmax, a longitudinal study may provide more pertinent information.

Assessment of Diaphragm Weakness

Thirty patients with breathlessness and diaphragm weakness were studied by measuring transdiaphragmatic pressures during maximal inspirations to total lung capacity, maximal static inspiratory efforts from residual volume, and maximal sniffs from functional residual capacity. Maximal static respiratory mouth pressures were also recorded, and rib cage and abdominal movements were monitored with pairs of magnetometers. Sniff transdiaphragmatic pressure was abnormally low in all patients and was correlated with transdiaphragmatic pressure during other maneuvers, and with maximal static inspiratory mouth pressures. There was no relationship between the severity of dyspnea and transdiaphragmatic pressure in the group as a whole. The weakest patients had orthopnea and paradoxical inward inspiratory motion of the anterior abdominal wall; measurements suggested that at least 30 cm H2O transdiaphragmatic pressure was required to overcome the hydrostatic pressure of the abdominal contents. By contrast, patients with mild diaphragm weakness had neither orthopnea nor abdominal paradox. Thus, patients with breathlessness and diaphragm dysfunction may have varying degrees of diaphragm weakness that may be difficult to detect clinically; the diagnosis and quantification of diaphragm weakness requires the measurement of transdiaphragmatic pressure.

Acid maltase deficiency in adults presenting as respiratory failure

During the past nine years 10 patients with the adult form of acid maltase deficiency have been observed at the Mayo Clinic. Three of the adults presented with respiratory failure. In all three the respiratory manifestations dominated the clinical picture and the cause of the respiratory failure (muscle weakness) and the underlying myopathy (glycogen storage disease) were initially unsuspected. Careful evaluation of the respiratory function tests, including the maximal static respiratory pressures, electromyographic examination and histochemical and biochemical studies of muscle biopsy specimens eventually led to the correct diagnosis.

Maximal static respiratory pressures in generalized neuromuscular disease.

Maximal static respiratory pressures were determined by a simplified method in a group of patients with neuromuscular disease and were more frequently abnormal than the vital capacity, maximal midexpiratory flow, or maximal breathing capacity. This method detected muscle weakness even in the presence of coexistent intrapulmonary disease and was helpful in evaluating dyspnea in these patients. Early in the disease, the maximal static respiratory pressures can be abnormal even though the results of spirometry are normal.