Background

Infant pulmonary function testing using the raised volume rapid thoracoabdominal compression (RVRTC) technique requires sedation and is time consuming. Many cystic fibrosis (CF) centers do not have access to equipment and the utility of routine testing remains to be determined. We aimed to assess whether RVRTC tests performed during infancy predict spirometry at early school age.

Methods

The RVRTC-based forced expiratory flow measures in infants were compared to the first adequately performed spirometry at school age. All tests were carried out during routine clinic visits and expressed as age related z-scores; only test occasions where patients were considered stable were included in the analysis.

Results

47 patients had useable infant RVRTC as well as matching school age spirometry data. There was weak correlation between infant FEV_0.5 and early school age FEV₁ (R = 0.29, p = 0.05). Four infants had significantly low zFEV_0.5 (zFEV_0.5 < -1.96), of which one of those remained under that limit at childhood. Changes in spirometry between infancy and early childhood were negatively correlated to baseline FEV_0.5 (R = 0.61 p<0.001) reflecting that the change was driven by where individuals started off with. There was no difference in clinical characteristics between those improving, those with stable or deteriorating in lung function.

Conclusion

Infant RVRTC measures were not predictive of pulmonary function in early school age, likely due to the high proportion of measures of forced expiratory flows within the normal range at both time points.

中文翻译：

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婴儿肺活量测定作为囊性纤维化患者儿童早期肺功能的预测指标

背景

使用增大容积快速胸腹加压 (RVRTC) 技术进行婴儿肺功能测试需要镇静并且耗时。许多囊性纤维化 (CF) 中心无法使用设备，常规检测的效用仍有待确定。我们的目的是评估在婴儿期进行的 RVRTC 测试是否可以预测学龄早期的肺活量。

方法

将基于 RVRTC 的婴儿用力呼气流量测量与第一次在学龄时充分进行的肺活量测量进行了比较。所有测试均在常规门诊就诊期间进行，并以与年龄相关的 z 分数表示；只有患者被认为稳定的测试场合才包括在分析中。

结果

47 名患者有可用的婴儿 RVRTC 以及匹配的学龄肺活量数据。_{婴儿 FEV 0.5}与学龄早期 FEV ₁之间存在弱相关性（R  = 0.29，p  = 0.05）。四名婴儿的 zFEV 0.5 显着降低_（ zFEV _0.5 < -1.96），其中一名婴儿在儿童期仍低于该限值。婴儿期和儿童早期的肺活量变化与基线 FEV _0.5呈负相关（R  = 0.61 p<0.001）反映了变化是由个人开始的地方驱动的。肺功能改善者、稳定者或恶化者的临床特征无差异。

结论

婴儿 RVRTC 测量不能预测学龄早期的肺功能，这可能是由于在两个时间点的正常范围内用力呼气流量测量的比例很高。