scholarly journals Peak In- and Expiratory Flow Revisited: Reliability and Reference Values in Adults

Respiration ◽  
2021 ◽  
pp. 1-8
Author(s):  
Shane Hanon ◽  
Eef Vanderhelst ◽  
Walter Vincken ◽  
Daniel Schuermans ◽  
Sylvia Verbanck
Keyword(s):  
Clinical Practice ◽  
Reference Values ◽  
Intraclass Correlation ◽  
Inspiratory Flow ◽  
Forced Expiration ◽  
Flow Measurements ◽  
Flow Rates ◽  
Reference Equations ◽  
Expiratory Flow ◽  
Age Range

<b><i>Background:</i></b> While peak in- and expiratory flow rates offer valuable information for diagnosis and monitoring in respiratory disease, these indices are usually considered too variable to be routinely used for quantification in clinical practice. <b><i>Objectives:</i></b> The aim of the study was to obtain reproducible measurements of maximal inspiratory flow rates and to construct reference equations for peak in- and expiratory flows (PIF and PEF). <b><i>Method:</i></b> With coaching for maximal effort, 187 healthy Caucasian subjects (20–80 years) performed at least 3 combined forced inspiratory and expiratory manoeuvres, until at least 2 peak inspiratory flow measurements were within 10% of each other. The effect on PIF preceded by a slow expiration instead of a forced expiration and PIF repeatability over 3 different days was also investigated in subgroups. Reference values and limits of normal for PIF, mid-inspiratory flow, and PEF were obtained according to the Lambda-Mu-Sigma statistical method. <b><i>Results:</i></b> A valid PIF could be obtained within 3.3 ± 0.6(SD) attempts, resulting in an overall within-test PIF variability of 4.6 ± 3.2(SD)%. A slow instead of a forced expiration prior to forced inspiration resulted in a significant (<i>p</i> &#x3c; 0.001) but small PIF increase (2.5% on average). Intraclass correlation coefficient for between-day PIF was 0.981 (95% CI: 0.960–0.992). Over the entire age range, inter-subject PIF variability was smaller than in previous reports, and PIF could be predicted based on its determinants gender, age, and height (<i>r</i><sup>2</sup> = 0.53). <b><i>Conclusions:</i></b> When adhering to similar criteria for the measurement of effort-dependent portions of inspiratory and expiratory flow-volume curves, performed according to current ATS/ERS standards, it is possible to obtain reproducible PIF and PEF values for use in routine clinical practice.

Mechanism of reduced maximum expiratory flow in dogs with compensatory lung growth

1986 ◽  
Vol 60 (2) ◽  
pp. 441-448 ◽  
Author(s):  
H. W. Greville ◽  
M. E. Arnup ◽  
S. N. Mink ◽  
L. Oppenheimer ◽  
N. R. Anthonisen
Keyword(s):  
Control Flow ◽  
Sham Operation ◽  
Forced Expiration ◽  
Flow Limitation ◽  
Lung Growth ◽  
Lung Volumes ◽  
Flow Rates ◽  
Compensatory Lung Growth ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow

We examined the mechanism of the reduced maximum expiratory flow rates (Vmax) in a dog model of postpneumonectomy compensatory lung growth. During forced expiration, a Pitot-static tube was used to locate the airway site of flow limitation, or choke point, and to measure dynamic intrabronchial pressures. The factors determining Vmax were calculated and the results analyzed in terms of the wave-speed theory of flow limitation. Measurements were made at multiple lung volumes and during ventilation both with air and with HeO2. Five of the puppies had undergone a left pneumonectomy at 10 wk of age, and 5 littermate controls had undergone a sham operation. All dogs were studied at 26 wk of age, at which time compensatory lung growth had occurred in the postpneumonectomy group. Vmax was markedly decreased in the postpneumonectomy group compared with control, averaging 42% of the control flow rates from 58 to 35% of the vital capacity (VC). At 23% of the VC, Vmax was 15% less than control. Choke points were more peripheral in the postpneumonectomy dogs compared with controls at all volumes. The total airway pressure was the same at the choke-point airway in the postpneumonectomy dogs as that in the same airway in the control dogs, suggesting that the airways of the postpneumonectomy dogs displayed different bronchial area-pressure behavior from the control dogs. Despite the decreased Vmax on both air and HeO2, the density dependence of flow was high in the postpneumonectomy dogs and the same as controls at all lung volumes examined.

Peak in- and expiratory flow rates: reproducibility and reference values in adults

2020 ◽  
Author(s):  
Shane Hanon ◽  
Eef Vanderhelst ◽  
Walter Vincken ◽  
Daniël Schuermans ◽  
Sylvia Verbanck
Keyword(s):  
Reference Values ◽  
Flow Rates ◽  
Expiratory Flow ◽  
Expiratory Flow Rates

scholarly journals Yoga Practice Has Minor Influence on Respiratory Function at Rest in Men and Women

2018 ◽  
Vol 1 (88) ◽  
Author(s):  
Kristina Zaičenkovienė ◽  
Arvydas Stasiulis ◽  
Roma Aleksandravičienė ◽  
Loreta Stasiulevičienė
Keyword(s):  
Pulmonary Function ◽  
Respiratory Function ◽  
Vital Capacity ◽  
Inspiratory Flow ◽  
Hatha Yoga ◽  
Forced Expiration ◽  
Yoga Practice ◽  
Men And Women ◽  
Minor Influence ◽  
Expiratory Flow

Research background and hypothesis. Hatha yoga breathing has the potential of training the respiratory system in such a way that it helps an individual to cope with the respiratory demand (Ray et al., 2011).Research aim was to compare pulmonary function variables between physically inactive subjects and the ones practicing hatha yoga and to evaluate changes after 6 months of yoga practice in the latter group. Research methods. Pulmonary function was measured by means of the gas analyser “Oxycon Mobile” (Germany) before and after 6 months of yoga training in men (n = 11) (age – 30.8 (7.06), BMI – 25.6 (2.6)) and women (n = 11) (age – 28.9 (6.86), BMI – 22.5 (2.3)) practicing yoga and control subjects (n = 22) of similar age. Measurements included forced vital capacity (FVC), forced expiration volume in one second (FEV(1)), forced inspiratory volume in one second FIV1, vital capacity (VC), peak expiratory flow (PEF), forced expiratory flow rate (FEF (25–75)%), forced inspiratory flow at 50% of the vital capacity (FIF50%), maximum voluntary ventilation (MVV), vital capacity (VC MAX), peak inspiratory flow (PIF), etc.Research results. Pulmonary function measures FEF 75/85 (L/s) (p = 0.036), total volume inspired FVC IN (L) (p = 0.014), FIV1 (L) (p = 0.045) were significantly higher in the group practicing yoga than in the control group of women, and VC MAX (%) (p = 0.018), FEV 1 (%) (p = 0.041), FEF 25 (L/s) (p = 0.017), FVC IN (L) (p = 0.002) in men practicing yoga, than in men not practicing yoga. They also demonstrated higher values of MVV (L/min)  (p = 0.068) and FVC (L) (p = 0.050). After 6 months of practicing yoga we found higher FEF 50 (L/s) (p = 0.003), FEF 50% (L/s) (p = 0.003) in women’s group and VCMAX (%) (p = 0.028) in men’s group. We also found a tendency of the increase of VCMAX (L) (p = 0.053), PIF (L/s) (p = 0.051), FVC IN (L) (p = 0.061), FIVI (L)  (p = 0.064) indexes in men and PIF (L/s) (p = 0.072), FVC IN (L) (p =  0.076) in women.Discussion and conclusions. Yoga practice appeared to have minor influence on respiratory function at rest in men and women of middle age. Additional studies examining various yoga practices are warranted to gain a more comprehensive understanding of the effects of yoga techniques on pulmonary functions.Keywords: pulmonary function at rest, yoga training, yoga breathing.

OBSTRUCTIVE DISEASE OF THE AIRWAYS IN CYSTIC FIBROSIS

PEDIATRICS ◽  
1968 ◽  
Vol 41 (3) ◽  
pp. 560-573
Author(s):  
Robert B. Mellins ◽  
O. Robert Levine ◽  
Roland H. Ingram ◽  
Alfred P. Fishman
Keyword(s):  
Cystic Fibrosis ◽  
Vital Capacity ◽  
Maximum Flow ◽  
Transpulmonary Pressure ◽  
Forced Expiration ◽  
Lung Volumes ◽  
Flow Rates ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow ◽  
Expiratory Flow Rates

A study of the interrelationships of instantaneous air flow, lung volume, and transpulmonary pressure over the range of the vital capacity has demonstrated striking differences in the determinants of maximum expiratory flow in cystic fibrosis and asthma. At high lung volumes, maximum expiratory flow rates in asthma are limited by the mechanical characteristics of the lungs and airways, whereas in cystic fibrosis and in the normal they are dependent on effort. At lower lung volumes, maximum expiratory flow rates are relatively more reduced in cystic fibrosis than in asthma and pressures in excess of those required to produce maximum flow actually depress flow. Also, forced expiration is associated with a transient reversal in the slope of the single breath nitrogen curve in cystic fibrosis and not in asthma. From these studies it is concluded that: (1) airway obstruction is less uniform and involves larger airways in cystic fibrosis than in asthma, and (2) increased expiratory pressure is associated with collapse of some of the larger airways over most of the range of the vital capacity in cystic fibrosis. A major clinical implication of these studies is that the effectiveness of cough is impaired by large airway collapse in cystic fibrosis.

Reference Values For Forced Expiration Parameters In Bulgarian Children And Adolescents Aged 7 To 18 Years

Folia Medica ◽  
2012 ◽  
Vol 54 (4) ◽  
pp. 29-36 ◽  
Author(s):  
Stoilka K. Mandadzhieva ◽  
Blagoi I. Marinov ◽  
Stefan S. Kostianev
Keyword(s):  
Children And Adolescents ◽  
Reference Values ◽  
Linear Regression Analysis ◽  
Body Height ◽  
Multiple Linear Regression Analysis ◽  
Forced Expiratory Volume ◽  
Fat Free Mass ◽  
Forced Expiration ◽  
Data Set ◽  
Reference Equations

Abstract INTRODUCTION: A diagnosis of lung function impairment in childhood is highly dependent on the respective reference values. Population differences in the pulmonary function of children have been frequently reported. The AIM of this study was to derive normal spirometric reference values for Bulgarian children and adolescents and to compare these results with other data set including our own reference equations developed 20 years ago. MATERIAL AND METHODS: Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and parameters of maximum expiratory flow-volume curves were measured in 671 healthy Bulgarian school children (339 males and 332 females) aged 7-18 years. Multiple linear regression analysis was performed for each spirometric parameter against age, height, weight, chest circumferences and fat free mass in both sexes. RESULTS: Excluding ratios, all measured spirometric parameters increased nonlinearly with age and height, and were significantly higher in boys than girls in adolescence. Height (H) explained the maximum variance for spirometric parameters and the best-fit regression equation relating functional parameters and body height was a power function (Y = a.Hb). FVC and FEV1 showed close correlations with height (r2 between 0.85 and 0.92), whereas the coefficients of determination for the flows were less close (r2 from 0.85 for PEF to 0.67 for MEF25%; always higher in boys). CONCLUSIONS: The developed prediction equations can be used in clinical practice. In comparison with reference equations based on European or USA populations, regional reference values are biologically more suitable for the interpretation of spirometric data.

scholarly journals Fecal calprotectin in healthy children aged 4–16 years

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
María Roca ◽  
Ana Rodriguez Varela ◽  
Eva Carvajal ◽  
Ester Donat ◽  
Francisco Cano ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Prospective Study ◽  
Reference Values ◽  
Fecal Calprotectin ◽  
Healthy Children ◽  
A Prospective Study ◽  
Age Range

AbstractReference values of fecal calprotectin (fCP) have not been convincingly established in children. We aimed to investigate fCP concentrations in a larger population of healthy children aged 4–16 years to analyze more in depth the behavior of fCP in this age range and to determine if cut-off levels could be conclusively recommended. A prospective study was conducted to investigate fCP concentrations of healthy children aged 4–16 years. In 212 healthy children, the median and 95th percentile for fCP were 18.8 mg/kg and 104.5 mg/kg, respectively. We found a statistically significant association between the 95th percentile of fCP concentrations and age (p < 0.001). We propose a nomogram to facilitate the interpretation of fCP results in children aged 4–16 years. Further studies are required to validate the proposed values in clinical practice.

scholarly journals Changes in Inspiratory and Expiratory Flow Rates with Sustained Hand Grip and their Correlation with Fat Free Mass Index in Healthy Young Adults

2021 ◽  
Author(s):  
Aparajita Priyadarshini ◽  
Snigdha Prava Mishra ◽  
Akshaya Kumar Mishra
Keyword(s):  
Muscle Mass ◽  
Inspiratory Flow ◽  
Fat Free Mass ◽  
P Value ◽  
Flow Rates ◽  
Flow Parameters ◽  
Hand Grip ◽  
Respiratory Flow ◽  
Expiratory Flow ◽  
Expiratory Flow Rates

Introduction: Aerobic exercises which are isotonic in nature have been proved to be beneficial in a number of cardiovascular and lifestyle diseases. But the effect of isometric exercises on cardiovascular and respiratory system is not fully evaluated. Existing literature on effect of isometric exercise on respiratory flow parameters are scanty and needs to be studied. Further, the impact of muscle mass on respiratory flow parameters need to be evaluated. Aim: To investigate the change in respiratory flow parameters (Peak Inspiratory Flow (PIF), Maximal Inspiratory Flow (MIF) 50, Peak Expiratory Flow (PEF), Maximum Expiratory Flow (MEF) 25-75, MEF 25, MEF 50 and MEF 75) in response to Sustained hand grip exercise and to find out any correlation between these flow parameters and Fat Free Mass Index (FFMI). Materials and Methods: A cross-sectional study was conducted at Department of Physiology, MKCG Medical College, Berhampur University, Odisha between October 2011 and August 2014. A total of 150 healthy volunteers aged between 17 to 25 years were included in the study. Anthropometric measurements were recorded using standardised instruments. Body fat percentage was measured by Bioelectric Impedance Analysis technique and then Fat Free Mass (FFM) and FFMI were calculated using standard formulae. Respiratory Flow parameters were assessed using Flow handy Spirometer as per the American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. Sustained hand grip exercise was performed with Physilab Grip Dynamometer. IBM SPSS Statistics Version 24.0, was used for statistical analysis. Paired sample t-test was used to compare lung volumes at baseline and after 3 minutes of sustained hand grip exercise. The p-value <0.05 was considered statistically significant. Karl Pearson Correlation coefficient was used to study the linear relationship between FFMI and various inspiratory and expiratory flow rates. Results: The mean values of all respiratory flow parameters under study decreased at 3 minutes of sustained hand grip exercise as compared to baseline values. This change was statistically significant for PEF (p-value 0.012), MEF 25-75 (p-value 0.041), MEF 50 (p-value 0.001), MEF 75 (p-value 0.012) and MIF50 (p-value 0.004) (p<0.05). All the flow rates studied except MEF 25 showed significant positive correlation with FFMI (r-values between 0.231 to 0.380, p<0.05) but the strength of association was low. Conclusion: There was a statistically significant reduction in both inspiratory and expiratory flow parameters with isometric sustained hand grip exercise. So, isometric exercises should be avoided in patients with obstructive airway diseases. But muscle mass should be improved for better ventilation as authors observed a positive correlation between FFMI and respiratory flow rates.

scholarly journals Reference values for spirometry in elderly individuals: a cross-sectional study of different reference equations

2019 ◽  
Vol 13 ◽  
Author(s):  
Joana Belo ◽  
Teresa Palmeiro ◽  
Iolanda Caires ◽  
Ana L. Papoila ◽  
Marta Alves ◽  
...  
Keyword(s):  
Reference Values ◽  
Reference Population ◽  
Cross Sectional Study ◽  
Forced Expiratory Volume ◽  
Nhanes Iii ◽  
Sample Population ◽  
Cross Sectional ◽  
Reference Equations ◽  
Predicted Values ◽  
Age Range

Background: Spirometry is the single most important test for the evaluation of respiratory function. The results are interpreted by comparing measured data with predicted values previously obtained from a reference population. Reference equations for spirometry have been discussed previously. The aim of this study was to compare reference values based on National Health and Nutrition Assessment Survey (NHANES III), European Community of Steel and Coal (ECSC), and Global Lung Initiative (GLI) equations in an elderly sample population. Methods: Subjects from the Geriatric Study on Health Effects of Air Quality in elder care centres who met the inclusion criteria were enrolled. Spirometry was performed according to international guidelines. The forced vital capacity, forced expiratory volume in 1 s, and FEV1/FVC ratio were reported as percentages of the predicted value, and the lower limit of normality was calculated. Results: Out of 260 elderly patients, 69.6% were women; the mean age was 83.0 ± 6.46 years with an age range of 65– 95 years. The lowest %FVC and %FEV1 values were obtained using the GLI reference equations. However, when NHANES III equations were used, the FEV1/FVC ratio was higher than ratios obtained from GLI and ECSC equations. The prevalence of airway obstruction was highest using ECSC equations, while GLI equations demonstrated more restrictive defects. Conclusions: The present study showed meaningful differences in the reference values, and consequently, in the results obtained using NHANES III, ECSC,  and GLI reference equations. The spirometry interpretation was also influenced by the reference equations used.

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