Division of Respiratory Medicine, Dept. of Paediatrics, University Hospital of Bern, Bern, Switzerland.
Eur Respir J. 2013 Feb;41(2):339-45. doi: 10.1183/09031936.00044312. Epub 2012 May 17.
In cystic fibrosis (CF), tests for ventilation inhomogeneity are sensitive but not established for clinical routine. We assessed feasibility of a new double-tracer gas single-breath washout (SBW) in school-aged children with CF and control subjects, and compared SBW between groups and with multiple-breath nitrogen washout (MBNW). Three SBW and MBNW were performed in 118 children (66 with CF) using a side-stream ultrasonic flowmeter setup. The double-tracer gas containing 5% sulfur hexafluoride and 26.3% helium was applied during one tidal breath. Outcomes were SBW phase III slope (SIII(DTG)), MBNW-derived lung clearance index (LCI), and indices of acinar (S(acin)) and conductive (S(cond)) ventilation inhomogeneity. SBW took significantly less time to perform than MBNW. SBW and MBNW were feasible in 109 (92.4%) and 98 (83.0%) children, respectively. SIII(DTG) differed between children with CF and controls, mean±sd was -456.7±492.8 and -88.4±129.1 mg·mol·L(-1), respectively. Abnormal SIII(DTG) was present in 36 (59%) children with CF. SIII(DTG) was associated with LCI (r= -0.58) and S(acin) (r= -0.58), but not with S(cond). In CF, steeply sloping SIII(DTG) potentially reflects ventilation inhomogeneity near the acinus entrance. This tidal SBW is a promising test to assess ventilation inhomogeneity in an easy and fast way.
在囊性纤维化（CF）中，通气不均匀性的检测具有较高的敏感性，但尚未在临床常规中得到确立。我们评估了一种新的双示踪剂气体单次呼吸洗脱（SBW）在 CF 患儿和对照组学龄儿童中的可行性，并比较了组间 SBW 与多呼吸氮洗脱（MBNW）之间的差异。使用侧流超声流量计设备，对 118 名儿童（66 名 CF 患儿）进行了 3 次 SBW 和 MBNW 检测。双示踪剂气体包含 5%六氟化硫和 26.3%氦气，在一次潮气呼吸中应用。结果是 SBW 第三相斜率（SIII（DTG））、MBNW 衍生的肺清除指数（LCI）以及腺泡（S（acin））和传导（S（cond））通气不均匀性的指数。SBW 完成时间明显短于 MBNW。SBW 和 MBNW 在 109 名（92.4%）和 98 名（83.0%）儿童中均可行。CF 患儿和对照组之间的 SIII（DTG）存在差异，平均值±标准差分别为-456.7±492.8 和-88.4±129.1 mg·mol·L(-1)。36 名（59%）CF 患儿存在异常 SIII（DTG）。SIII（DTG）与 LCI（r=-0.58）和 S（acin）（r=-0.58）相关，但与 S（cond）无关。在 CF 中，陡峭的 SIII（DTG）可能反映了腺泡入口附近的通气不均匀性。这种潮气 SBW 是一种很有前途的测试方法，可以通过简单快速的方式评估通气不均匀性。
