潮气呼气流速-容量环对支气管肺发育不良患儿肺功能的监测

Role of tidal breath flow-volume loop in monitoring lung function of preterm infants with bronchopulmonary dysplasia

目的:探讨潮气呼吸流速-容量环对支气管肺发育不良(brouchopulmonary dysplasia,BPD)患儿肺功能的评估作用。方法:选取无严重心肺疾病的非BPD早产儿(113例)为对照组,BPD早产儿为观察组,根据BPD诊断标准分为轻、中、重3组(分别为48例,42例,16例)。在校正胎龄44周时检测各组潮气呼吸流速-容量曲线(tidal breath flow-volume loop,TBFVL)和功能残气量(functional residual capacity,FRC)、肺清除指数(lung clearance index,LCI)。结果:(1)TBFVL形态分析:与对照组相比,BPD轻、中、重组呼气达峰提前,呼气峰流量明显高于吸气峰流量,呼气降支陡峭,BPD轻组呼气降支斜率增加,BPD中、重组呼气降支明显向容量轴凹陷。(2)肺功能指标:除BPD中组外,BPD轻、重组呼气达峰容积比均比对照组低(均P<0.05);BPD重组吸气峰流量、呼气峰流量、75%潮气量时呼气流速均比BPD轻组和对照组高(均P<0.05);25%潮气量时呼气流速除BPD重组比对照组高外,BPD轻、中组均比对照组低(均P<0.05);BPD中、重组FRC比对照组低,LCI只有BPD中组比对照组高(均P<0.05)。(3)相关性:除LCI外,呼气达峰容积/呼气量、吸气峰流量、呼气峰流量、75%潮气量时呼气流速、25%潮气量时呼气流速、FRC均与BPD严重程度相关(均P<0.05)。结论:BPD患儿由于肺泡、终末小气道发育不良,导致TBFVL呼气降支斜率增加,中、重度BPD患儿呼气降支出现凹陷。TBFVL能直观反映BPD患儿肺功能状况,可结合FRC、LCI用于BPD患儿肺发育的监测。

Objective ：To investigate the roles of tidal breath flow-volume loop（TBFVL） in monitoring lung function of preterm infants with different degrees＇ bronchopulmonary dysplasia（BPD）. Methods：One hundred and thirteen preterm infants without BPD and heart ＆ lung disease-free were erolled as controls and 106 BPD infants were taken as observation group.Observation group was divided into mile, moderate and severe groups according to the definition of BPD. Parameters of lung function test,including TBFVL, functional residual capacity （FRC） and lung clearance index（LCI） were coected and analyzed when the patients were at 44 weeks postmen- strural age（PMA）. Results： （~）Shape of TBFVL showed that in observation groups ：ratio of volume to peak tidal expiratory volume a- gainst expiratory volume（Vpef/Ve） was decreased,peak expiratory flow（TPEF） was markedly higher than peak inspiratory flow（TPIF）. Expiratory descending branch was descended sharply;expiratory descending branch of mild observation group was slightly gradient than that of control group;expiratory descending branch of moderate and severe groups was depressed to volume axis. Compared with parameters in control group：except moderate observation group,Vpef/Ve in mild and severe observation group were lower（P〈0.05） ;TPIF, TPEF,tidal expiratory flow at 75% remaining tidal volume （TEF75） in severe observation group were decreased compared with thosein mild observation group and control group（P〈0.05） ;tidal expi- ratory flow at 25% remaining tidal volume（TEF25） was lower in mild and moderate observation groups than in control group, while it was higher in severe group than in control group （P〈 0.05） ; FRC was lower in moderate and severe observation groupsthan in control group ;only in moderate observation group;LCI was higher than moderate observation group in control group（P〈0.05）. Spearman correlation analysis showed that FRC,Vpef/Ve,TPIF,TPEF,TEF75,TEF25 had strong correlationship with the degree of BPD with statistical significances while LCI not. Conclusions ： Because of the dysplasia of pulmonary alveoli and terminal small air- way, expiratory descending branch of TBFVL in BPD infants is descended sharply and in moderate and severe BPD infants even de- pressed to volume axis.TBFVL can directly reflect the lung function condition of BPD infants and can be used in clinical for lung de- velopement follow-up combining with FRC, LCI.