学龄前哮喘儿童常用吸入器阻力下吸气峰流量的研究

Peak inspiratory flow generated through different analogue inhalers in asthma preschool children.

目的探讨吸气峰流量与儿童年龄及肺通气功能的相关性，为临床合理选择适用于学龄前哮喘儿童的吸入器提供客观的依据。方法2006年1月至5月，于广州呼吸疾病研究所，使用In—Check DAIL吸气峰流量检测仪，对56例学龄前（3～6岁）哮喘急性发作期儿童和58例健康学龄前儿童分别进行无阻力状态（N）及常用吸入器Surehaler（S）、Autohaler（A）、Diskus（D）、Turbohaler（T）阻力状态下吸气峰流量（PIF）测定，并同时测定其肺通气功能。测量指标包括：PIF—N、PIF—S、PIF—A、PIF—D、PIF—T、用力肺活量（FVC）、第0．5秒用力呼气客积（FEV0.5）、第0．75秒用力呼气容积（FEV0.75）、第1秒用力呼气容积（FEV1）、最大呼气中段流量（FEF25-75）、最高呼气流量（PEF）等。结果在成功完成测试的44例哮喘组和48例对照组学龄前儿童中，两组间的FVC、FEV0.5、FEV0．75、FEV1、FEF25-75及以上指标％预计值和FEV1／FVC差异均无统计学意义（P〉0．05）；PEF在两组间差异有统计学意义（P=0．004）。其中哮喘组有8例的FEV。％预计值低于80％（最小值为52％），对照组有6例的FEV。％预计值低于80％（最小值为69％），两组间异常率差异无统计学意义（P〉0．05）。两组学龄前儿童PIF-N、PIF-S、PIF-A、PIF-D、PIF—T在3岁与4岁年龄段之间差异无统计学意义（P〉0．05），但3岁与5岁、6岁年龄段差异均有统计学意义（P〈0．05）；随年龄增长，各吸气峰流量有明显增高趋势。在4种吸入器阻力状态下的吸气峰流量值两组学龄前儿童之间差异均无统计学意义（P〉0．05）。各年龄段哮喘组和对照组儿童的PIF-S、PIF—A、PIF—D达到各自吸入器所要求达到的最小流量（Surehaler20L／min、Autohaler30L／min、Diskus30L／min）的例数比例均为100％，哮喘组PIF-T达到Turbohaler所需最小流量（60L／min）的例数比例为88．6％、对照组为89．6％，不能迭标者主要是存在轻度阻塞性通气功能障碍或为3～5岁儿童。两组在各阻力模拟状态下的PIF与肺通气功能主要指标（FVC、FEV0．5、FEV0．75、FEV1、PEF）均有较好的相关性，其中以PEF与PIF—N相关性最佳（两组Pearson相关系数均〉0．6）。结论年龄和肺通气功能是影响学龄前儿童吸气峰流量的重要因素，通过对学龄前儿童进行常规肺功能测试，可评估其吸气能力的大小；在对学龄前哮喘儿童进行吸入治疗前，常规使用In-Check DIAL模拟各种常用吸入器的内部阻力以测试其吸气峰流量值，将对合理选择适用的最佳吸入器有重要指导意义，从而达到个体化治疗的目的。

Objective To study the relationship of peak inspiratory flow with children＇s age and pulmonary ventilation so as to provide the objective basis for choosing proper inhalers for asthma preschool children. Methods A survey in 56 asthma and 58 healthy preschool children aged 3 to 6 years old was carried out in Guangdong. Peak inspiratory flow ＇s PIF ） was measured without and with resistances ,which mimic the internal resistances of several inhalersrs——Surehaler, Autohaler, Diskus ,Turbohaler by PIF meter （ In-check DIAL ） and then data of PIF-N, PIF-S, PIF-A, PIF-D and PIF-T were of Italian. These spirometry parameters include forced vital capacity （FVC）, forced expiratory volume at 0. 5 second （FEV0.5） ,forced expiratory volume at 0.75 second（ FEV0.75） forced expiratory volume at one second （FEV1） and maximal mid expiratory flow rate（ FEF25 -75 ） . Results Results were obtained from 44 asthma children and 48 health children aged 3 -6 years who successfully finished the test. There were no significantly difference on FVC, FVC% pred, FEV0.5, FEV0.5 % pred, FEV0 75, FEV0 75 % pred, FEV1 , FEV1% pred, FEV1/FVC, FEF25 -75 and FEF25-75 % pred between two groups except for PEF. The PIF-N, PIF-S, PIF-A, PIF-D and PIF-T were significant different between aged 3yrs and 5yrs and 6yrs in two groups. The peak inspiratory flow significantly increased with age. The PIFs in different inhalers were various because of the different inner resistances. The minimum and optimum PIFs in resistances of Surehaler, Autohaler and Diskus could be achieved by almost all subjects,but those in resistances of Turbohaler could only be achieved by 88.6% asthma and 89.6% health subjects, most of whom were aged 3yrs. There were good correlations between the PIFs in different resistances and main parameters of ventilation function, and PEF was the best among them （ Pearson correlative coefficient was 0.6）. Conclusion We can predict and assess the inspiratory ability of the children by using routine measurement of lung function in asthma pre-school children. As to the pre-school children of varying ages ,the variety of inspiratory ability should be considered completely in the selection of inhaler used during the treatment. The best inhaler suitable for them shoud be selected properly in order to obtain the purpose Of treating individually.