Abstract：
BACKGROUND: The diagnosis of mild-moderate equine asthma (MEA) can be confirmed by airway endoscopy, bronchoalveolar lavage fluid (BALf) cytology, and lung function evaluation by indirect pleural pressure measurement. Oscillometry is a promising pulmonary function test method, but its ability to detect subclinical airway obstruction has been questioned.
OBJECTIVE: To evaluate the differences in lung function measured by oscillometry between healthy and MEA-affected horses.
METHODS: Prospective case-control clinical study.
METHODS: Thirty-seven horses were divided into healthy and MEA groups, based on history and clinical score; the diagnosis of MEA was confirmed by airway endoscopy and BALf cytology. Horses underwent oscillometry at frequencies ranging from 2 to 6 Hz. Obtained parameters included whole-breath, inspiratory, expiratory, and the difference between inspiratory and expiratory resistance (Rrs) and reactance (Xrs). Differences between oscillometry parameters at different frequencies were evaluated within and between groups by repeated-measures two-way ANOVA and post hoc tests with Bonferroni correction. Frequency dependence was compared between groups by t test. For significant parameters, a receiver operating characteristics curve was designed, cut-off values were identified and their sensitivity and specificity were calculated. Statistical significance was set at p < 0.05.
RESULTS: No significant differences in Xrs and Rrs were observed between groups. The frequency dependence of whole-breath and inspiratory Xrs significantly differed between healthy (respectively, -0.03 ± 0.02 and -0.05 ± 0.02 cmH2O/L/s) and MEA (-0.1 ± 0.03 and -0.2 ± 0.02 cmH2O/L/s) groups (p < 0.05 and p < 0.01). For inspiratory Xrs frequency dependence, a cut-off value of -0.06 cmH2O/L/s was identified, with 86.4% (95% CI: 66.7%-95.3%) sensitivity and 66.7% (95% CI: 41.7%-84.8%) specificity.
CONCLUSIONS: Sample size, no BALf cytology in some healthy horses.
CONCLUSIONS: Oscillometry can represent a useful non-invasive tool for the diagnosis of MEA. Specifically, the evaluation of the frequency dependence of Xrs may be of special interest.
OBJECTIVE: To evaluate the differences in lung function measured by oscillometry between healthy and MEA-affected horses.
METHODS: Prospective case-control clinical study.
METHODS: Thirty-seven horses were divided into healthy and MEA groups, based on history and clinical score; the diagnosis of MEA was confirmed by airway endoscopy and BALf cytology. Horses underwent oscillometry at frequencies ranging from 2 to 6 Hz. Obtained parameters included whole-breath, inspiratory, expiratory, and the difference between inspiratory and expiratory resistance (Rrs) and reactance (Xrs). Differences between oscillometry parameters at different frequencies were evaluated within and between groups by repeated-measures two-way ANOVA and post hoc tests with Bonferroni correction. Frequency dependence was compared between groups by t test. For significant parameters, a receiver operating characteristics curve was designed, cut-off values were identified and their sensitivity and specificity were calculated. Statistical significance was set at p < 0.05.
RESULTS: No significant differences in Xrs and Rrs were observed between groups. The frequency dependence of whole-breath and inspiratory Xrs significantly differed between healthy (respectively, -0.03 ± 0.02 and -0.05 ± 0.02 cmH2O/L/s) and MEA (-0.1 ± 0.03 and -0.2 ± 0.02 cmH2O/L/s) groups (p < 0.05 and p < 0.01). For inspiratory Xrs frequency dependence, a cut-off value of -0.06 cmH2O/L/s was identified, with 86.4% (95% CI: 66.7%-95.3%) sensitivity and 66.7% (95% CI: 41.7%-84.8%) specificity.
CONCLUSIONS: Sample size, no BALf cytology in some healthy horses.
CONCLUSIONS: Oscillometry can represent a useful non-invasive tool for the diagnosis of MEA. Specifically, the evaluation of the frequency dependence of Xrs may be of special interest.
摘要：
背景：轻度-中度马哮喘（MEA）的诊断可以通过气道内窥镜检查来确认，支气管肺泡灌洗液（BALf）细胞学，通过间接胸膜压测量评价肺功能。振荡是一种很有前途的肺功能检查方法，但其检测亚临床气道阻塞的能力受到质疑。
目的：评估通过示波法测量的健康和受MEA影响的马之间的肺功能差异。
方法：前瞻性病例对照临床研究。
方法：37匹马分为健康组和MEA组，根据病史和临床评分；通过气道内镜和BALf细胞学检查证实了MEA的诊断。马在2至6Hz的频率范围内进行了振荡测量。获得的参数包括整个呼吸，吸气,呼气,以及吸气和呼气阻力(Rrs)和电抗(Xrs)之间的差异。通过重复测量的双向ANOVA和使用Bonferroni校正的事后检验，评估了组内和组间不同频率的振荡参数之间的差异。组间频率依赖性比较采用t检验。对于重要的参数，设计了接收机工作特性曲线，确定截断值,并计算其敏感性和特异性.统计学显著性设定为p<0.05。
结果：两组间Xrs和Rrs无显著差异。整个呼吸和吸气Xrs的频率依赖性在健康者之间显着不同（分别，-0.03±0.02和-0.05±0.02cmH2O/L/s）和MEA（-0.1±0.03和-0.2±0.02cmH2O/L/s）组（p<0.05和p<0.01）。对于吸气Xrs频率依赖性，确定了-0.06cmH2O/L/s的截止值，敏感性为86.4%（95%CI：66.7%-95.3%），特异性为66.7%（95%CI：41.7%-84.8%）。
结论：样本量，一些健康的马没有进行BALf细胞学检查。
结论：示波法可以代表诊断MEA的有用的非侵入性工具。具体来说,对Xrs的频率依赖性的评估可能是特别感兴趣的。
目的：评估通过示波法测量的健康和受MEA影响的马之间的肺功能差异。
方法：前瞻性病例对照临床研究。
方法：37匹马分为健康组和MEA组，根据病史和临床评分；通过气道内镜和BALf细胞学检查证实了MEA的诊断。马在2至6Hz的频率范围内进行了振荡测量。获得的参数包括整个呼吸，吸气,呼气,以及吸气和呼气阻力(Rrs)和电抗(Xrs)之间的差异。通过重复测量的双向ANOVA和使用Bonferroni校正的事后检验，评估了组内和组间不同频率的振荡参数之间的差异。组间频率依赖性比较采用t检验。对于重要的参数，设计了接收机工作特性曲线，确定截断值,并计算其敏感性和特异性.统计学显著性设定为p<0.05。
结果：两组间Xrs和Rrs无显著差异。整个呼吸和吸气Xrs的频率依赖性在健康者之间显着不同（分别，-0.03±0.02和-0.05±0.02cmH2O/L/s）和MEA（-0.1±0.03和-0.2±0.02cmH2O/L/s）组（p<0.05和p<0.01）。对于吸气Xrs频率依赖性，确定了-0.06cmH2O/L/s的截止值，敏感性为86.4%（95%CI：66.7%-95.3%），特异性为66.7%（95%CI：41.7%-84.8%）。
结论：样本量，一些健康的马没有进行BALf细胞学检查。
结论：示波法可以代表诊断MEA的有用的非侵入性工具。具体来说,对Xrs的频率依赖性的评估可能是特别感兴趣的。
