Galant Stanley P, Fregeau William, Pabelonio Neil, Morphew Tricia, Tirakitsoontorn Pornchai
Breathmobile Department, Children's Hospital of Orange County, Orange, Calif; Department of Pediatrics, University of California Irvine, Irvine, Calif.
Department of Cardiopulmonary Service, Children's Hospital of Orange County, Orange, Calif.
J Allergy Clin Immunol Pract. 2020 Sep;8(8):2698-2706. doi: 10.1016/j.jaip.2020.03.040. Epub 2020 Apr 15.
Although clinically useful in identifying peripheral airway impairment (PAI), impulse oscillometry (IOS) has not received universal acceptance. This may be due to variable cutoff points, and the perception that available standardized reference values may not be clinically relevant in all populations.
To establish the relationship between PAI, based on standardized IOS reference values, and uncontrolled asthma as well as interchangeability between Hispanic and white reference algorithms.
IOS reference values were established for upper and lower limits of normal (>95th and <5th percentile, respectively) using published algorithms in Hispanic and white children. Values exceeding normal limits (PAI) were compared in those uncontrolled and controlled for significance of differences. Probability estimates and odds ratio of uncontrolled asthma were determined for R5, R5-R20, AX, and X5 using adjusted generalized estimating equation analyses. Intraclass correlation coefficients determined interchangeability of Hispanic and white reference algorithm values.
Those with uncontrolled asthma had significantly greater PAI and a higher frequency of PAI than those well controlled (P < .05), whereas odds of uncontrolled asthma increased with increasing PAI (P < .001) for all IOS measures, particularly for X5, where odds ratios ranged from 2.70 to 11.01.There was good to excellent (>70%) agreement between Hispanic and white algorithms, except for R5-R20 (<70%).
PAI, defined by IOS reference values, not central airway markers (R20), is consistently related to the risk of uncontrolled asthma. This is true whether using Hispanic or white reference algorithms. Thus, standardized reference values in children offer the clinician readily available IOS cutoff points that are clinically relevant across ethnicity.
尽管脉冲振荡法（IOS）在识别外周气道功能障碍（PAI）方面具有临床应用价值，但尚未得到广泛认可。这可能是由于截断点的差异，以及人们认为现有的标准化参考值在所有人群中可能与临床实际情况不符。
基于标准化的IOS参考值，建立PAI与未控制哮喘之间的关系，以及西班牙裔和白人参考算法之间的互换性。
使用已发表的算法，为西班牙裔和白人儿童建立正常范围上下限（分别为>第95百分位数和<第5百分位数）的IOS参考值。比较超过正常范围（PAI）的未控制组和控制组之间的差异是否具有统计学意义。使用调整后的广义估计方程分析，确定R5、R5-R20、AX和X5未控制哮喘的概率估计值和比值比。组内相关系数确定西班牙裔和白人参考算法值的互换性。
未控制哮喘患者的PAI显著高于控制良好的患者（P < 0.05），未控制哮喘的发生率也更高。对于所有IOS测量指标，尤其是X5，未控制哮喘的比值比随着PAI的增加而增加（P < 0.001），比值比范围为2.70至11.01。除R5-R20外（<70%），西班牙裔和白人算法之间的一致性良好至优秀（>70%）。
由IOS参考值定义的PAI，而非中央气道指标（R20），与未控制哮喘的风险始终相关。无论使用西班牙裔还是白人参考算法，都是如此。因此，儿童标准化参考值为临床医生提供了易于获得的IOS截断点，这些截断点在不同种族中均具有临床相关性。
