Source: Annual Congress 2011 - Role of the biomarkers in airway diseases
Disease area: Airway diseases

Abstract

Background
The interest in alveolar NO, one of the flow independent parameters, is increasing since it is elevated in severe and nocturnal asthma and in COPD. The nonlinear approach (Högman-Meriläinen Algorithm) with low, medium and high flow rates has been used to calculate C_ANO, D_awNO and C_awNO. The aim was to set how low and how high these flow rates should be.
Methods
Subjects (n=32), without classifications of disease, volunteered to exhale with eight flow rates between 10 and 350 mL/s. NO was measured by CLD 88sp NO analyzer (ECO Medics AG, Switzerland). The subjects were grouped according to low, normal and high F_ENO_0.05. The correction for axial diffusion was applied (Condorelli et al. 2004).
Results
There was a significant difference (p=0.001) in C_awNO and D_awNO (p=0.001) with the use of 30 instead of 10 mL/s. The C_ANO values were significantly different with the use of 250 instead of 350 mL/s (p=0.001). The three groups had C_ANO of 0.9±0.2, 0.9±0.1 and 0.9±0.3 ppb respectively. With correction of axial diffusion the C_ANO became 0.3±0.2, -0.5±0.2 and -2.7±0.6 ppb with majority of values being negative.
Conclusion
The flow independent NO parameters are flow dependent. With the use of the nonlinear model with the HMA approach to calculate C_ANO, D_awNO and C_awNO the flow rates to be used use are 10, 100 and 350 for adults. Further studies have to be done in children that cannot perform these low and high flow rates. Most importantly, the axial diffusion correction is of limited value with the HMA method.
Abbreviation: HMA=Högman-Meriläinen algorithm, C_ANO= alveolar NO, C_awNO=airway wall NO, D_awNO=airway transfer factor of NO

Rating:

Share or cite this content

Citations should be made in the following way:
M. Högman, P. Meriläinen (Gävle, Uppsala, Sweden). Are the flow independent NO parameters flow dependent?. Eur Respir J 2011; 38: Suppl. 55, 4780

Member's Comments

No comment yet.

Related content which might interest you: Validation of the assessment of flow limitation at rest by overlapping of the tidal and maximal flow volume curves Source: Annual Congress 2009 - Quality control in lung function and new developments Year: 2009 A model-based analysis of the effect of hypoxia on regional pulmonary blood flow Source: Annual Congress 2011 - Physiology of human pulmonary hypertension Year: 2011 Peak flow is not strictly comparable by gauge and spirometry in many patients Source: Annual Congress 2011 - Quality of diagnosis and assessment in primary care Year: 2011 Kinetic parameters of muscle O2 extraction at the onset of exercise to assess blood flow to O2 uptake mismatch in disease populations Source: Annual Congress 2010 - Peripheral and respiratory muscles oxygen transport during exercise Year: 2010 Improving the quality of serial peak flow measurements Source: Eur Respir J 2001; 18: Suppl. 33, 281s Year: 2001 Comparison of peak expiratory flow values between Cipla peak flow master and Wrights peak flow meter Source: Eur Respir J 2006; 28: Suppl. 50, 221s Year: 2006 An evaluation of peak expiratory flow measured on the smart peak flow meter Source: Virtual Congress 2020 – Occupational exposure as a cause of respiratory disease Year: 2020 Is there a need to perform both spirometry and flow volume loops? Source: Eur Respir J 2003; 22: Suppl. 45, 147s Year: 2003 New and old formula for predicting mean pulmonary artery pressure from doppler – assessed flow parameters in comparison with hemodynamic parameters Source: Eur Respir J 2006; 28: Suppl. 50, 424s Year: 2006 The effect of image plane location on MRI-based measurements of pulmonary blood flow distribution Source: Annual Congress 2010 - Parenchmya and bronchial carcinoma Year: 2010 Reference values for lung mechanics studied with sinusoidal flow regulation Source: Eur Respir J 2005; 26: Suppl. 49, 363s Year: 2005 Reproducibility in parameters of forced inspiratory flow Source: Annual Congress 2009 - Functional insights into COPD Year: 2009 The ideal gas solubility for the measurement of pulmonary blood flow from gas exchange Source: Eur Respir J 2003; 22: Suppl. 45, 86s Year: 2003 Blood flow cytometric analysis in stable asthmatics Source: Eur Respir J 2005; 26: Suppl. 49, 589s Year: 2005 Continuous measurement of peak expiratory flow – to whom and how long? Source: Annual Congress 2007 - Assessing asthma severity and control in children Year: 2007 Impact of leakage on external flow measurement in non-invasive ventilation Source: Annual Congress 2012 - Recent technical developments in long-term noninvasive ventilation Year: 2012 Measurement of lung volume and ventilation distribution with an ultrasonic flow meter in healthy infants Source: Eur Respir J 2002; 20: 912-918 Year: 2002 Assessment of portable oxygen concentrators to revert induced hypoxia by hypoxic challenge testing in paediatric patients. A comparative study between continuous flow and pulse flow delivery systems. Source: International Congress 2019 – New developments in sleep-disordered breathing, gas exchange and lung function in children Year: 2019 Variability of the peak inspiratory flow (PIF) measurement Source: Eur Respir J 2001; 18: Suppl. 33, 204s Year: 2001