scholarly journals Airway Conductance

2020 ◽  
Author(s):  
Keyword(s):  
Airway Conductance

Deep breaths, methacholine, and airway narrowing in healthy and mild asthmatic subjects

2002 ◽  
Vol 93 (4) ◽  
pp. 1384-1390 ◽  
Author(s):  
Emanuele Crimi ◽  
Riccardo Pellegrino ◽  
Manlio Milanese ◽  
Vito Brusasco
Keyword(s):  
Forced Vital Capacity ◽  
Healthy Subjects ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Forced Expiration ◽  
Airway Narrowing ◽  
Significant Difference ◽  
Mild Asthmatic ◽  
Residual Capacity ◽  
Airway Conductance

Deep breaths taken before inhalation of methacholine attenuate the decrease in forced expiratory volume in 1 s and forced vital capacity in healthy but not in asthmatic subjects. We investigated whether this difference also exists by using measurements not preceded by full inflation, i.e., airway conductance, functional residual capacity, as well as flow and residual volume from partial forced expiration. We found that five deep breaths preceding a single dose of methacholine 1) transiently attenuated the decrements in forced expiratory volume in 1 s and forced vital capacity in healthy ( n = 8) but not in mild asthmatic ( n = 10) subjects and 2) increased the areas under the curve of changes in parameters not preceded by a full inflation over 40 min, during which further deep breaths were prohibited, without significant difference between healthy ( n = 6) and mild asthmatic ( n = 16) subjects. In conclusion, a series of deep breaths preceding methacholine inhalation significantly enhances bronchoconstrictor response similarly in mild asthmatic and healthy subjects but facilitates bronchodilatation on further full inflation in the latter.

Could Be % MMEF and sGaw Determinant Diagnostic Parameters Between Partial Reversibility and Reversibility in Evaluating Short-Acting Bronchodilator Response?

2021 ◽  
Author(s):  
Gökhan Erdoğan ◽  
Elif Altuğ ◽  
Sacide Rana Işık ◽  
Levent Tabak
Keyword(s):  
Independent Predictor ◽  
Binary Logistic Regression ◽  
Threshold Value ◽  
Test Results ◽  
Binary Logistic Regression Model ◽  
Bronchodilator Response ◽  
Significant Difference ◽  
Post Hoc ◽  
The Relationship ◽  
Airway Conductance

INTRODUCTION: By examining the relationship between changes in maximum mild-expiratory flow( MMEF) and specific airway conductance(sGaw), parameters with the change in FEV1 when evaluating the spirometer test and the bronchodilator response, we investigated their diagnostic contribution to the bronchodilator response in those with partial responses to FEV1. METHODS: The retrospective study sample consists of data from 112 patients between Jun 1, 2019, and Feb 1, 2020 who applied to the pulmonary function laboratory with a pre-diagnosis of bronchial hyperreactivity as well as body plethysmography test performed together with the reversibility test. RESULTS: MMEF% and ▲sGaw were linearly correlated with ▲FEV1 (respectively r = 0.752; p <0.001, r = 0.611; p <0.001). While there was a significant difference between ▲MMEF% and ▲sGaw between reversible, partially reversible, and irreversible groups (P <0.001), there was no significant difference in ▲sGaw between partial reversible and reversible groups in post-hoc comparisons (P> 0.05). In the binary logistic regression model created between the partially reversible and reversible groups, demographic characteristics, MMEF% and ▲sGaw variables, ▲MMEF was an independent predictor [OR: 1.132; 95% CI (1.036-1.238), p = 0.006]. The 24% threshold for absolute reversibility or partial reversibility calculated with MMEF% was significant, indicating significance at 86.2% sensitivity and 80.8% specificity (AUC: 0.811, 95% CI: 0.686-0.936; p <0.001). This value we found defined 81% of the partially reversible group as reversible. DISCUSSION AND CONCLUSION: We observed that ▲sGaw alone didn' have a determinant contribution for determining reversibility in bronchodilator response, which showed partial reversibility with respect to FEV1 change. We believe that ▲MMEF% can be an independent predictor between these two groups and the calculated threshold value of 24% can be used as a criterion for determining the reversibility in cases where FEV1 is not determinant.

Variability Of Airway Conductance (SGaw) In Healthy Volunteers

2010 ◽  
Author(s):  
Steven D. Greenaway ◽  
Suzannah Blackwell ◽  
Nisha Jhali ◽  
Jenny Stenning ◽  
Darren Wilbraham ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Airway Conductance

scholarly journals Assessing Airway Resistance Using Plethysmography as Lung Function Testing Among Asymptomatic Rheumatoid Arthritis Patients.

2021 ◽  
Vol 11 (6) ◽  
pp. 116-124
Author(s):  
Abdulrhman Mustafa Rasheed ◽  
Ahmed Fadlalla ◽  
Fadelelmoula Tarig ◽  
Wael F Asmaa Hegazy Alblowi ◽  
Fawaz Alshammari Saitah
Keyword(s):  
Rheumatoid Arthritis ◽  
Lung Function ◽  
Airway Resistance ◽  
Lung Function Testing ◽  
Mean Values ◽  
Pulmonary Manifestations ◽  
Medical City ◽  
Respiratory Mechanism ◽  
Function Testing ◽  
Airway Conductance

Pulmonary events in rheumatoid arthritis (RA) reflects the involvement of pleurae, lung interstitium, and airways. Overall, pulmonary manifestations are estimated to cause 10–20% of mortalities in RA. Respiratory system involvement as extra-articular presentations of RA is common among some Saudi patients. This study aims to evaluate specific airway conductance (sGaw), airway resistance (Raw), and specific airway resistance (sRaw), using plethysmography. Comparison for deployed methods is made by forced spirometer as an indicator for obstruction among patients with RA. The study sought to use the methods to enhance lung testing among RA patients. An analytical, hospital-based study was carried out at pulmonary function test laboratory, department of respiratory care King Saud Medical City (KSMC). RA patients were selected, with an age group of 18-75years. The tests for Forced spirometer and plethysmography were carried out to assess and analyze how the respiratory mechanism was impacted by the disease. Data collected was analyzed using Statistical Package for Social Sciences (SPSS), version 21. The obstructive and mixed ventilation patterns constituted 15%; the mean values of Raw and sRaw were significantly higher compared to mean values predicted for participants selected during the study, while sGaw was significantly lower compared to mean values predicted for participants selected. Monitoring of airway resistance parameters using plethysmography can be used as indicators of lung function testing among RA patients.

scholarly journals Cardiorespiratory disorders in preschool aged children associated with aerogenic impact of benzene, phenol and formaldehyde

2019 ◽  
Vol 95 (1) ◽  
pp. 70-74
Author(s):  
Olga A. Maklakova ◽  
S. L. Valina
Keyword(s):  
Qt Interval ◽  
Respiratory Diseases ◽  
Creatine Phosphokinase ◽  
Reference Group ◽  
Cell Activity ◽  
Glutathione S Transferase ◽  
Chronic Respiratory Diseases ◽  
School Aged Children ◽  
Proliferative Cell ◽  
Airway Conductance

There was performed an examination of 437 pre-school aged children living in the conditions of the pollution of atmospheric air with benzene, phenol andformaldehyde. Children with the elevated blood content of benzene, phenol andformaldehyde were detected to be diagnosed as having chronic respiratory diseases and asteno-neurotic syndrome by 3 and 1.3 times more often, respectively, in contrast to the reference group. Cardiorespiratory disorders in children with the elevated content of benzene, phenol and formaldehyde are manifested by restrictive and mixed disorders of airway conductance followed by the increase in markers of proliferative cell activity (CA-72-4 and M 20), changes in the electrophysiologicalprocesses in cardiac muscle pronounced by the decreased electric ventricular systole (QT interval) followed by the decline of the content in blood of glutathione-S-transferase, zAMF, nitrogen oxide and the increase in the lipids hydroperoxide level, and creatine phosphokinase activity.

The effect of facial cold stimulation on airway conductance in healthy man

1969 ◽  
Vol 47 (5) ◽  
pp. 453-457 ◽  
Author(s):  
W. T. Josenhans ◽  
G. N. Melville ◽  
W. T. Ulmer
Keyword(s):  
Airway Resistance ◽  
Facial Skin ◽  
Air Trapping ◽  
Cold Stimulation ◽  
Resistance Increase ◽  
Cold Receptors ◽  
Residual Capacity ◽  
Young Subjects ◽  
Airway Conductance ◽  
Stimulation Of

The effect on airway conductance (Gaw) and functional residual capacity (FRC) of stimulation of cold receptors in facial skin was studied in 12 healthy young subjects, with a body plethysmograph. Mean Gaw decreased significantly, from 0.44 to 0.38 liter s−1 cm−1 H2O, in 10 subjects. FRC was only slightly affected, probably because the experiment was too brief to allow air-trapping. It is concluded that the Gaw decrease during exposure to cold results from bronchoconstriction due to (a) stimulation of trigeminal nerve cold receptors and to (b) pharyngeal and glottal airway resistance increase resulting from frequent involuntary 'dry' swallowing.

Effect of Oral Diuretics on Pulmonary Mechanics in Infants with Chronic Bronchopulmonary Dysplasia: Results of a Double-Blind Crossover Sequential Trial

PEDIATRICS ◽  
1984 ◽  
Vol 74 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Lily C. Kao ◽  
David Warburton ◽  
Mary H. Cheng ◽  
Cecilia Cedeño ◽  
Arnold C. G. Platzker ◽  
...  
Keyword(s):  
Weight Gain ◽  
Bronchopulmonary Dysplasia ◽  
Sequential Analysis ◽  
Crossover Trial ◽  
Fluid Intake ◽  
Pulmonary Mechanics ◽  
Double Blind ◽  
Phosphorus Excretion ◽  
Phosphorus Depletion ◽  
Airway Conductance

In a randomized double-blind crossover trial with sequential analysis, the effects of oral diuretics were compared with the effects of placebo on pulmonary mechanics in ten infants with bronchopulmonary dysplasia (BPD). Pulmonary mechanics were measured before and at the end of a week of treatment with oral diuretics (chlorothiazide, 20 mg/kg/dose and spironolactone, 1.5 mg/kg/dose) given twice daily, or placebo. Mean airway resistance decreased 35.3 cm H2O/L/s, mean specific airway conductance increased 0.095 1/L/s/cm H2O, and mean dynamic pulmonary compliance increased 1.74 mL/cm H2O during treatment with diuretics (all P &lt;.001), but not during treatment with placebo. The infants' rate of weight gain decreased on the first three days of diuretic treatment, but was thereafter comparable with weight gain during treatment with placebo. Fluid intake was similar in infants receiving diuretics and placebo. But, infants receiving diuretics not only had significantly increased urine output, osmolal clearance, and potassium and phosphorus excretion, but these infants also retained less fluid, and, in addition, excreted less calcium than infants receiving placebo. It is concluded that oral diuretics improve lung function in infants with chronic bronchopulmonary dysplasia; however, potassium and phosphorus depletion are potential complications of treatment.

Airway responses to inhaled ouabain and histamine in conscious guinea pigs

1986 ◽  
Vol 60 (6) ◽  
pp. 2089-2093 ◽  
Author(s):  
K. P. Agrawal ◽  
R. E. Hyatt
Keyword(s):  
Guinea Pigs ◽  
Airway Responsiveness ◽  
Maximal Response ◽  
Response Curves ◽  
Inhibiting Effect ◽  
Homeostatic Function ◽  
Positive Correlations ◽  
Airway Responses ◽  
Airway Conductance

Tracheal Na+-K+-ATPase activity is positively correlated with in vivo airway responsiveness to histamine. We wondered whether this were a chance association or whether it was directly related to the mechanism of hyperreactivity. Therefore, we obtained dose-response curves to aerosols of histamine and ouabain in guinea pigs to determine whether an in vivo relationship existed between the excitatory effects of histamine and the enzyme-inhibiting effect of ouabain. Airway responsiveness to ouabain was measured as the ouabain concentration producing a 30% decrease in specific airway conductance (ED30) or that producing a half-maximal response (ED50). Responsiveness to histamine was measured either as ED30 or as ED50. Significant positive correlations were noted between the log ED50 of ouabain and log histamine ED30 or ED50 (r = 0.81 and 0.83, respectively; P less than 0.001), and between log ouabain ED30 and log histamine ED30 and ED50 (r = 0.76 and 0.77, respectively; P less than 0.002). Pretreatment with ouabain increased airway responsiveness to histamine (P less than 0.05). We suggest that in hyperreactive airways Na+-K+-ATPase serves a homeostatic function of preventing Na+ and Ca2+ loading of the cell and that it is not directly responsible for the hyperreactivity.

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