Danish Pediatric Pulmonary Service, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, Australia; Discipline of Pediatrics and Child Health, Sydney Medical School, University of Sydney, Australia.
Respir Med. 2018 Jul;140:94-100. doi: 10.1016/j.rmed.2018.06.006. Epub 2018 Jun 6.
Ex-premature school children show mild-to-moderate airway obstruction and decreased CO diffusing capacity. Multiple breath nitrogen washout (N2MBW) and NO diffusing capacity (DLNO) measurements may provide new insight into long-term pulmonary and vascular impairment in bronchopulmonary dysplasia (BPD).
We examined a randomly selected group of 70 ex-premature children (gestational age <28 weeks or birth weight <1500 g; 42 with and 28 without BPD) and 38 term-born healthy controls of 8-13 years of age. Subjects performed N2MBW (lung clearance index, LCI; Sacin, and Scond), DLNO (membrane related diffusing capacity, Dm and pulmonary capillary volume, Vc), Fractional exhaled NO, CO diffusing capacity, conventional spirometry (FEV1, FVC, FEF25-75) and plethysmography (RV, TLC). Respiratory symptoms were assessed by questionnaire.
Compared to healthy controls, the BPD group had higher z-scores for lung clearance index (P = 0.003), Sacin (P = 0.005), lower CO diffusing capacity (P = 0.025), DLNO (P = 0.022), DLNO/VA z-scores (P = 0.025) and a significant larger proportion had respiratory complaints. Amongst ex-premature children, the BPD group did not differ from the non-BPD group except for a decreased Dm (P = 0.023). Ex-premature with BPD showed predominantly airway obstruction (FEV1/FVC; P < 0.0001), signs of hyperinflation (RV/TLC-ratio; P = 0.028), and 25% had a positive bronchodilator response (>12% in FEV1).
Ex-premature school children exhibited relatively mild but significant long-term respiratory symptoms and pulmonary peripheral impairment judged by N2MBW and DLNO measurements along with well-known airway obstruction. Larger longitudinal studies are needed to assess the clinical use of these advanced methods of assessing ventilation inhomogeneity and DLNO.
早产儿表现出轻至中度气道阻塞和一氧化碳弥散能力降低。多次呼吸氮冲洗（N2MBW）和一氧化氮弥散能力（DLNO）测量可能为支气管肺发育不良（BPD）的长期肺和血管损害提供新的见解。
我们检查了一组随机选择的 70 名早产儿（胎龄<28 周或出生体重<1500g；其中 42 名患有 BPD，28 名无 BPD）和 38 名足月出生的 8-13 岁健康对照组。受试者进行 N2MBW（肺清除指数，LCI；Sacin 和 Scond）、DLNO（膜相关弥散能力，Dm 和肺毛细血管容积，Vc）、呼气一氧化氮分数、一氧化碳弥散能力、常规肺活量测定（FEV1、FVC、FEF25-75）和体描法（RV、TLC）。通过问卷调查评估呼吸症状。
与健康对照组相比，BPD 组的肺清除指数（LCI）z 评分较高（P=0.003），Sacin 较高（P=0.005），一氧化碳弥散能力（P=0.025）、DLNO（P=0.022）、DLNO/VA z 评分较低（P=0.025），且有呼吸症状的比例显著较高。在早产儿中，BPD 组与非 BPD 组除了 Dm 降低（P=0.023）外，无其他差异。BPD 的早产儿主要表现为气道阻塞（FEV1/FVC；P<0.0001）、过度充气征象（RV/TLC-比；P=0.028），25%有阳性支气管扩张剂反应（FEV1 增加>12%）。
早产儿表现出相对较轻但明显的长期呼吸症状和肺外周损害，判断依据是 N2MBW 和 DLNO 测量，以及众所周知的气道阻塞。需要更大的纵向研究来评估这些评估通气不均匀性和 DLNO 的先进方法的临床应用。
