分析间隔对呼出气一氧化氮多导呼出气流分段技术的影响
2010/04/14
哮喘患者呼出气一氧化氮（eNO）含量增加，且被认为是气道炎症的一个标志。通过检测不同流速eNO和应用eNO交换动力学模型，信号可分为近端气道[J’awNO (nl/sec)]和远端气道/肺泡[CANO (ppb)]信号。诸多研究显示其在儿童哮喘检测中的重要性。但eNO分区的技术存在差异，因而不能进行不同研究的比较。
本研究检测分析间隔（时间或体积）对eNO稳定浓度及J’awNO和CANO估测值的影响。对30例轻度至中度哮喘患儿检测不同流速（50、100和200 ml/sec）肺活量及eNO。各流速eNO稳定浓度采用两种方法分析：（1）时间间隔常数；（2）体积间隔常数。该两种分析方法，具有轴向扩散的双室模型分析J’awNO和CANO特征。当流速为200 ml/sec时，时间间隔分析预测的eNO值小于体积间隔分析。两种方法检测的CANO存在显著差异（体积间隔分析>时间间隔分析）。若采用多流量技术检测eNO分区，分析法（时间间隔常数和体积间隔常数）对CANO的预测值具有显著影响，因而对评估和解释远端肺炎症产生影响。
（林江涛 审校）
Pediatr Pulmonol. 2010 Jan 15. [Epub ahead of print]
Part 1: Asthma (13)
Impact of analysis interval on the multiple exhalation flow technique to partition exhaled nitric oxide.
Puckett JL, Taylor RW, Galant SP, George SC.
Department of Biomedical Engineering, University of California at Irvine, Irvine, California 92697.
Exhaled nitric oxide (eNO) is elevated in asthmatics and is a purported marker of airway inflammation. By measuring eNO at multiple flows and applying models of eNO exchange dynamics, the signal can be partitioned into its proximal airway [J’ awNO (nl/sec)] and distal airway/alveolar contributions [CANO (ppb)]. Several studies have demonstrated the potential significance of such an approach in children with asthma. However, techniques to partition eNO are variable, limiting comparisons among studies. The objective of this study is to examine the impact of the analysis interval (time or volume) on eNO plateau concentrations and the estimation of J’awNO and CANO. In 30 children with mild to moderate asthma, spirometry and eNO at multiple flows (50, 100, and 200 ml/sec) were measured. The plateau concentration of eNO at each flow was determined using two different methods of analysis: (1) constant time interval and (2) constant volume interval. For both methods of analysis, a two-compartment model with axial diffusion was used to characterize J’awNO and CANO. At a flow of 200 ml/sec, the time interval analysis predicts values for eNO that are smaller than the volume interval analysis. As a result, there are significant differences in CANO between the methods of analysis (volume > time). When using the multiple flow technique to partition eNO, the method of analysis (constant time vs. constant volume interval) significantly affects the estimation of CANO, and thus potentially the assessment and interpretation of distal lung inflammation.
Pediatr Pulmonol. 2010 Jan 15. [Epub ahead of print]
本研究检测分析间隔（时间或体积）对eNO稳定浓度及J’awNO和CANO估测值的影响。对30例轻度至中度哮喘患儿检测不同流速（50、100和200 ml/sec）肺活量及eNO。各流速eNO稳定浓度采用两种方法分析：（1）时间间隔常数；（2）体积间隔常数。该两种分析方法，具有轴向扩散的双室模型分析J’awNO和CANO特征。当流速为200 ml/sec时，时间间隔分析预测的eNO值小于体积间隔分析。两种方法检测的CANO存在显著差异（体积间隔分析>时间间隔分析）。若采用多流量技术检测eNO分区，分析法（时间间隔常数和体积间隔常数）对CANO的预测值具有显著影响，因而对评估和解释远端肺炎症产生影响。
（林江涛 审校）
Pediatr Pulmonol. 2010 Jan 15. [Epub ahead of print]
Part 1: Asthma (13)
Impact of analysis interval on the multiple exhalation flow technique to partition exhaled nitric oxide.
Puckett JL, Taylor RW, Galant SP, George SC.
Department of Biomedical Engineering, University of California at Irvine, Irvine, California 92697.
Exhaled nitric oxide (eNO) is elevated in asthmatics and is a purported marker of airway inflammation. By measuring eNO at multiple flows and applying models of eNO exchange dynamics, the signal can be partitioned into its proximal airway [J’ awNO (nl/sec)] and distal airway/alveolar contributions [CANO (ppb)]. Several studies have demonstrated the potential significance of such an approach in children with asthma. However, techniques to partition eNO are variable, limiting comparisons among studies. The objective of this study is to examine the impact of the analysis interval (time or volume) on eNO plateau concentrations and the estimation of J’awNO and CANO. In 30 children with mild to moderate asthma, spirometry and eNO at multiple flows (50, 100, and 200 ml/sec) were measured. The plateau concentration of eNO at each flow was determined using two different methods of analysis: (1) constant time interval and (2) constant volume interval. For both methods of analysis, a two-compartment model with axial diffusion was used to characterize J’awNO and CANO. At a flow of 200 ml/sec, the time interval analysis predicts values for eNO that are smaller than the volume interval analysis. As a result, there are significant differences in CANO between the methods of analysis (volume > time). When using the multiple flow technique to partition eNO, the method of analysis (constant time vs. constant volume interval) significantly affects the estimation of CANO, and thus potentially the assessment and interpretation of distal lung inflammation.
Pediatr Pulmonol. 2010 Jan 15. [Epub ahead of print]
