负压呼气流量技术在儿童支气管哮喘患者中的应用

Study on negative expiratory pressure technique in children with bronchial asthma

目的探讨针对儿童支气管哮喘患者应用负压呼气流量(NEP)技术检测的临床意义。方法选择2016年3月至2018年3月在浙江省中西医结合医院儿科就诊的支气管哮喘患儿作为研究对象,按照哮喘临床评分标准分为轻度组(0~4分)和重度组(5~12分);选择同期健康体检儿童作为健康对照组。应用肺功能仪通过NEP技术检测呼吸功能和潮气量(VT),比较应用与未应用NEP时潮气呼吸流量-容量曲线(F-V曲线)的差异,根据应用NEP时出现EFL后呼出VT占未应用NEP时呼出VT的百分比计算呼气流量受限(EFL)指数。采用Pearson相关法分析EFL指数与病情严重程度的关系;绘制受试者工作特征曲线(ROC),分析EFL指数对支气管哮喘患儿病情严重程度的评估价值。结果研究期间共入选86例支气管哮喘患儿,其中2例因试验期间发生其他疾病而退出,最终84例完成测试并纳入分析,轻度组41例,重度组43例;同期42例健康体检儿童作为健康对照组。各组研究对象间性别、年龄比较差异均无统计学意义,检测过程中均未发生不良反应。支气管哮喘患儿EFL指数明显高于健康对照组,且随疾病严重程度加重而呈升高趋势〔轻度组与健康对照组:(30.60±6.03)%比(6.64±2.37)%,重度组与健康对照组:(33.70±5.41)%比(6.64±2.37)%,均P<0.05〕;而轻度组及重度组呼吸频率(RR)和VT与健康对照组比较差异均无统计学意义〔RR(次/min):31.45±4.18、32.81±4.07比31.97±4.01,VT(mL/kg):6.29±1.14、5.96±0.90比6.30±1.20,均P>0.05〕。相关性分析显示,支气管哮喘患儿EFL指数与疾病严重程度呈显著正相关(r=0.836,P=0.000)。ROC曲线分析显示,EFL指数预测支气管哮喘患儿病情严重程度的ROC曲线下面积(AUC)为0.801〔95%可信区间(95%CI)=0.725~0.878〕;当EFL指数的最佳截断值为29.21%时,敏感度为85.7%,特异度为69.2%,阳性预测值为75.1%,阴性预测值为60.2%。结论应用NEP技术测得的支气管哮喘患儿EFL指数与病情严重程度密切相关,EFL指数越高,病情越重;通过EFL指数可早期判断支气管哮喘患儿的病情严重程度,为支气管哮喘病情评估和治疗提供依据。

Objective To investigate the clinical significance of children bronchial asthma detection by using negative expiratory pressure (NEP) technique. Methods The children with bronchial asthma admitted to Department of Pediatrics of Zhejiang Provincial Integrated Traditional Chinese and Western Medicine Hospital from March 2016 to March 2018 were enrolled. They were divided into mild group (0-4 scores) and severe group (5-12 scores) according to asthma clinical scoring criteria. The children undergoing physical examination at the same period were served as healthy control group. NEP technique and tidal volume (VT) were detected by the pulmonary function instrument. Respiratory flow-volume curves (F-V curves) without NEP were compared with tidal F-V curves after NEP application to assess expiratory flow limitation (EFL). EFL index was calculated according to the percentage of expiratory VT after EFL and expiratory VT when NEP was not used. Pearson correlation method was used to analyze the relationship between EFL index and severity of bronchial asthma. Receiver operating characteristic (ROC) curve was plotted to analyze the value of EFL index in evaluating the severity of bronchial asthma in children. Results A total of 86 children with bronchial asthma were enrolled in the study, and 84 patients completed the test and 2 children withdrew due to other diseases. Finally, 84 patients were included in the final analysis, including 41 mild and 43 severe children. Forty-two healthy children in the same period were served as healthy control group. There was no significant difference in gender or age among the groups, and no adverse reactions occurred during the test. The EFL index of children with bronchial asthma was significantly higher than that of the healthy control group, and it was increased with the severity of the disease [mild group compared with healthy control group: (30.60±6.03)% vs. (6.64±2.37)%, severe group compared with healthy control group: (33.70±5.41)% vs. (6.64±2.37)%, both P < 0.05]. There was no significant difference in respiratory rate (RR) or VT between mild group or severe group and healthy control group [RR (times/min): 31.45±4.18, 32.81±4.07 vs. 31.97±4.01, VT (mL/kg): 6.29±1.14, 5.96±0.90 vs. 6.30±1.20, all P > 0.05]. It was shown by the correlation analysis that EFL index was positively correlated with the severity of asthma (r = 0.836, P = 0.000). It was shown by ROC curve analysis that the area under ROC curve (AUC) of EFL index for predicting the severity of bronchial asthma in children was 0.801 [95% confidence interval (95%CI) = 0.725-0.878];when the best cut-off value of EFL index was 29.21%, the sensitivity was 85.7%, the specificity was 69.2%, the positive predictive value was 75.1%, and the negative predictive value was 60.2%. Conclusions The EFL index measured by NEP technology was closely related to the severity of bronchial asthma. The higher the EFL index, the more serious of the condition. The severity of bronchial asthma could be early judged by EFL index, which provided a basis for the evaluation and treatment of bronchial asthma.