MacLean J E, DeHaan K, Fuhr D, Hariharan S, Kamstra B, Hendson L, Adatia I, Majaesic C, Lovering A T, Thompson R B, Nicholas D, Thebaud B, Stickland M K
Faculty of Medicine and Dentistry, Departments of Pediatrics, University of Alberta, Edmonton, Alberta, Canada Faculty of Medicine and Dentistry, Women & Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada.
Faculty of Medicine and Dentistry, Departments of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
Thorax. 2016 Nov;71(11):1012-1019. doi: 10.1136/thoraxjnl-2015-207736. Epub 2016 Jun 3.
Extreme preterm birth confers risk of long-term impairments in lung function and exercise capacity. There are limited data on the factors contributing to exercise limitation following extreme preterm birth. This study examined respiratory mechanics and ventilatory response during exercise in a large cohort of children born extremely preterm (EP).
This cohort study included children 8-12 years of age who were born EP (≤28 weeks gestation) between 1997 and 2004 and treated in a large regionalised neonatal intensive care unit in western Canada. EP children were divided into no/mild bronchopulmonary dysplasia (BPD) (ie, supplementary oxygen or ventilation ceased before 36 weeks gestational age; n=53) and moderate/severe BPD (ie, continued supplementary oxygen or ventilation at 36 weeks gestational age; n=50). Age-matched control children (n=65) were born at full term. All children attempted lung function and cardiopulmonary exercise testing measurements.
Compared with control children, EP children had lower airway flows and diffusion capacity but preserved total lung capacity. Children with moderate/severe BPD had evidence of gas trapping relative to other groups. The mean difference in exercise capacity (as measured by oxygen uptake (VO)% predicted) in children with moderate/severe BPD was -18±5% and -14±5.0% below children with no/mild BPD and control children, respectively. Children with moderate/severe BPD demonstrated a potentiated ventilatory response and greater prevalence of expiratory flow limitation during exercise compared with other groups. Resting lung function did not correlate with exercise capacity.
Expiratory flow limitation and an exaggerated ventilatory response contribute to respiratory limitation to exercise in children born EP with moderate/severe BPD.
极早早产会带来肺功能和运动能力长期受损的风险。关于极早早产后导致运动受限的因素的数据有限。本研究调查了一大群极早早产（EP）出生儿童在运动期间的呼吸力学和通气反应。
这项队列研究纳入了1997年至2004年间在加拿大西部一家大型区域化新生儿重症监护病房接受治疗的8至12岁极早早产（胎龄≤28周）儿童。极早早产儿童分为无/轻度支气管肺发育不良（BPD）组（即胎龄36周前停止补充氧气或通气；n = 53）和中/重度BPD组（即胎龄36周时仍持续补充氧气或通气；n = 50）。年龄匹配的对照儿童（n = 65）为足月出生。所有儿童均进行了肺功能和心肺运动测试测量。
与对照儿童相比，极早早产儿童的气道流量和弥散能力较低，但总肺容量保持不变。与其他组相比，中/重度BPD儿童有气体潴留的证据。中/重度BPD儿童的运动能力（以预测的摄氧量（VO）衡量）平均差异分别比无/轻度BPD儿童和对照儿童低-18±5%和-14±5.0%。与其他组相比，中/重度BPD儿童在运动期间表现出增强的通气反应和更高的呼气流量受限患病率。静息肺功能与运动能力无关。
呼气流量受限和过度的通气反应导致极早早产且患有中/重度BPD的儿童运动时出现呼吸受限。
