深圳地区正常学龄前儿童常用吸入器阻力状态下的最高吸气流量分析

目的 研究正常学龄前儿童在各种常用模拟吸入器阻力状态下的最大吸气能力,并探讨其与年龄、身高、体重及通气功能的相关性.方法 使用In-Check DAIL吸气流量检测仪及峰流量仪,对深圳地区3～6岁正常学龄前儿童370例进行常用吸入器[Surehaler气雾剂(Surehaler)、Autohaler气雾剂(Autohaler)、都保(Turbuhaler)、准纳器(Diskus)]阻力状态下吸气流量峰值(PIF)及呼气流量峰值(PEF)测定,同时采用意大利COSMED流量传感仪,测定其通气功能.测量指标包括:无阻力状态下的PIF(PIF-N)、模拟Surehaler时的PIF(PIF-S)、模拟Autohaler时的PIF(PIF-A)、模拟Turbuhaler时的PIF(PIF-T)、模拟Diskus时的PIF(PIF-D)、PEF、用力肺活量(FVC)、0.5秒用力呼气容积(FEVO.5)、0.75秒用力呼气容积(FEV0.75)、一秒用力呼气容积(FEV1)、最大呼气中段流量(FEF25-75)等.结果 (1)370例中有75例不能成功完成吸气或呼气功能测试,实际研究人数295例.PIF-S、PIF-A、PIF-T、PIF-D在3～岁组、4～岁组、5～岁组、6～7岁组各组之间差异有统计学意义,随着年龄增长、身高增高,各最高吸气流量亦明显增高.(2)各模拟阻力状态下PIF与年龄、身高和体重均有相关性,其中以与年龄、身高的相关性较好.(3)在正确完成测试儿童中,PIF-S、PIF-A、PIF-D达到各自吸人器所需最小流量比例均为100%,PIF-T达到Turbuhaler所需最小流量比例为87.5%,未达标学龄前儿童以3～岁组或身高在100 cm以下儿童为主.各阻力模拟状态下的PIF与通气功能主要指标均有较好的相关性,其中以PEF为最佳.结论 可通过正常学龄前儿童常规进行的肺通气功能测试预测其吸气能力的大小;对不同学龄前儿童选择吸入器时,应充分考虑到其吸气能力的大小.

Peak inspiratory flow generated through different analogue dry powder inhalers in Shenzhen healthy preschool children

Objective Dry powder inhalers(DPIs)are increasingly being used to deliver drugs for the treatment of asthma.It is known that DPIs require a crueial minimal inspiratory flow.Previous studies have demonstrated that the peak inspiratory flow(PIF,L/min)through a DPI is dependent on the type of device,the age of the patient,and the level of bronchial obstruction.However,the peak inspiratory flow of healtlly preschool children in China remains scant in the literature.The present study aimed to analyze the ability of inspifing flow through the resistance state of ordinary use inhaler in Shenzhen healthy preschool children by measuring the peak inspiratory flow through the different analogue dry powder inhalers and go further into the relationship between it and the age,weight and forced expiratory volume of the children.Method A survey in 370 healthy preschool children aged 3 to 6 years(75 children aged 3 years,104 children aged 4 years,100 children aged 5 years and 91 children aged 6 years)was carried out in Shenzhen.Peak inspiratory flow(PIF)was measured without and with resistances,which mimicked the internal resistances of several inhalers,Diskus,Turbuhaler,Autohaler,Surehaler by PIF meter(In-check DIAL)and then data PIF-N,PIF-D,PIF-T,PIF-A and PIF-S were obtained.Peak expiratory flow(PEF) was measured by PEF meter(MicroPeak,USA).These two measurements were made in a well-controlled setting,and at least three attempts were recorded to establish maximum achievement.Six spirometry parameters forced vital capacity(FVC),forced expiratory volume at 0.5 second(FEV 0.5),forced expiratory volume at 0.75 second(FEV 0.75),forced expiratory volume at one second(FEV1),maximal mid expiratory flow rate(FEF 25-75,PEF were measured by using COSMED spirometry of Italy and the FVC measurements should be around the quality control for spirometry in preschool children which we suggested and published in 2005.All data were expressed as mean±SD and analyzed with the statistical software SPSS 12.0 for Windows.Pearson's test was used for calculation of the significances of the correlation coefficients.Variance analysis was used for analysing the variability of inspiratory flows through the inhalers.Results Results were obtained from 295 children aged 3-6 years who successfully finished the tests.The PIF-N,PIF-D,PIF-T,PIF-A and PIF-S were significantly different among the groups aged 3 yrs,4 yrs,5 yrs and 6 yrs.The peak inspiratory flow significantly increased with age.The PIF-N,PIF-D,PIF-T,PIF-A and PIF-S in the children of 110 cm height and above were significantly higher than those in the children below 110 cm height,so were the parameters between the children of 120 cm height and above and the children below 120 cm.PIF correlated significantly with age,height and weight and the Pearson coefficient was 0.3-0.5.The PIFs in different inhalers varied because of the different inner resistances.The minimum and optimum PIFs in resistances of Diskus,Autohaler and Surehaler could be achieved in almost all subjects,but those in resistances of Turbuhaler could be achieved in only 87.5% subiects,most of whom aged 3 yrs or below 100 cm height.There were good correlations between the PIFs in difierent resistances and main parameters of ventilation function(FVC,FEV 0.5,FEV 0.75,FEV1,FEF 25-75,PEF),PEF was the best among them(Pearson correlative coeffieient was 0.6).Conclusion The inspiratory ability of the children. As to the pre-school children of varying ages, the variety of inspiratory ability shou8ld be considered completely in the selection of inhaler used during the treatment. The best inhaler suitable for them should be selected properly in order to obtain the best efficacy of treatment individually.