Matthews Iren Lindbak, Fredriksen Per Morten, Bjørnstad Per G, Thaulow Erik, Gronn Morten
Paediatric Department, Paediatric Pulmonology and Allergology Unit, Rikshospitalet University Hospital, Oslo, Norway.
Cardiol Young. 2006 Jun;16(3):261-7. doi: 10.1017/S1047951106000345.
Most children with functionally univentricular hearts nowadays are treated surgically by creating a total cavopulmonary connection. In the resulting Fontan circulation, the venous return and the pulmonary arterial bed are coupled in series, bypassing the heart. This gives the potential for interaction between the abnormal circulation and function of the lungs. In this study, we investigated the pattern of impairment of pulmonary function, and its relation to decreased exercise capacity. We performed spirometry in 33 (85 percent) of 39 eligible Norwegian children, aged from 8 to 16, with a total cavopulmonary connection, along with whole body plethysmography, the carbon monoxide single breath test, and a peak treadmill exercise test. The single breath test showed a mean corrected diffusing capacity of 66.5 percent of predicted, giving a z score of minus 2.88. The mean residual volume measured by whole body plethysmography was 146.8 percent, equivalent to a z score of 2.46, whereas the mean residual volume measured by the single breath test was 102.4 percent of predicted, this being the same as a z score of 0.43. The mean peak treadmill exercise test was 70.0 percent of predicted, equivalent with a z score of minus 3.07. Mean forced vital capacity was 85.7 percent of predicted, the equivalent z score being minus 0.92. Lung function correlated with the peak treadmill exercise test. We have shown, therefore, that children with the Fontan circulation have reduced diffusing capacity, possibly caused by the abnormal circulation through the lungs. The difference between residual volume measured by plethysmography and the single breath test implies trapping of air. The correlation of parameters for lung function with peak consumption of oxygen during exercise indicates that the abnormalities of pulmonary function may affect physical capacity.
如今，大多数功能性单心室心脏患儿通过建立全腔静脉肺动脉连接进行手术治疗。在由此产生的Fontan循环中，静脉回流和肺动脉床串联连接，绕过心脏。这使得异常循环与肺功能之间存在相互作用的可能性。在本研究中，我们调查了肺功能受损模式及其与运动能力下降的关系。我们对39名符合条件的挪威儿童中的33名（85%）进行了肺活量测定，这些儿童年龄在8至16岁之间，均有全腔静脉肺动脉连接，同时还进行了全身体积描记法、一氧化碳单次呼吸试验和峰值跑步机运动试验。单次呼吸试验显示平均校正弥散能力为预测值的66.5%，z评分为-2.88。通过全身体积描记法测得的平均残气量为146.8%，相当于z评分为2.46，而通过单次呼吸试验测得的平均残气量为预测值的102.4%，相当于z评分为0.43。平均峰值跑步机运动试验为预测值的70.0%，相当于z评分为-3.07。平均用力肺活量为预测值的85.7%，等效z评分为-0.92。肺功能与峰值跑步机运动试验相关。因此，我们已经表明，具有Fontan循环的儿童弥散能力降低，可能是由肺部异常循环引起的。体积描记法和单次呼吸试验测得的残气量差异意味着空气潴留。肺功能参数与运动期间峰值耗氧量的相关性表明，肺功能异常可能会影响身体能力。
