Objective To investigate the impact of using low limit of normal( LLN) for FEV1 /FVC ratio and fixed ratio ( 70% ) as cut-off point in the qualitative diagnosis on the prevalence of chronic obstructive pulmonary disease( COPD) . Methods An epidemiological study was carried out in preoperative patients who received pulmonary function test in Zhongshan hospital fromNovember 6, 2007 to December 30, 2007. 339 patients were enrolled and diagnosed as COPD by different diagnostic criteria as follows: ①GOLD criteria; ②FEV1 /FVC
目的 研究学龄前儿童鼓室图测试的正常值及其影响因素。 方法 2005年1月-2005年3月，对132名（223耳）学龄前儿童（4~6岁）进行单频率单成分鼓室图测试（Y-226），获取峰值处补偿静态声导纳（Ytm）、外耳道等效容积（Vea）、鼓室测量宽度（TW）和峰值处鼓室压（TPP）等数据，对不同年龄、性别及与国外研究的结果进行比较。 结果 不同年龄间只有TW存在差别；男童Vea大于女童，其他几项指标没有性别差异；Ytm、Vea、TW、TPP与国外正常值范围相比，有统计学意义（Plt;0.05）。 结论 单频率单成分鼓室图测试结果与国外研究相比有统计学意义，提示必须建立国人自己的正常鼓室图参考值标准。
Objective To establish amedical reference for adult pulmonary function parameters and a normal FEV1 /FVC% pred in population of Shanghai. Methods Subjects who underwent routine physical examination were initially screened and those who met enrollment criteria with age over 18 years old were required to underwent pulmonary function tests in Zhongshan Hospital from June 2009 to February 2010. After screening of 450 subjects, a total of 240 subjects with normal pulmonary function and 120 subjects with mild small airway abnormalities were enrolled in this study according to the prediction equations established in1988. All subjects were assigned into 6 groups according to their age with30 males amd 30 females in each group. Pulmonary function parameters including VC, FVC, FEV1 , FEV1 /FVC, PEF, FEF25% , FEF50% , FEF75% , RV, FRC, TLC, RV /TLC, DLCO, and KCO were collected for analysis. New prediction equations for the above 14 parameters were established by parameters of anthropometry. The medical reference ranges of 14 parameters were calculated according to the newprediction equations. The normal FEV1 /FVC%pred was also calculated. Results New prediction equations for normal adult pulmonary function parameters in Shanghai were established. DLCO =5.206 +4. 314 ×gender ( “male”= 1, “female”=0) - 0. 144 ×age( y) +0. 098 × height( cm) +0. 082 ×weight( kg) , KCO =9. 346 - 0. 026 ×age( y) - 0. 031 ×height( cm) +0. 025 ×weight( kg) .The LLN( P5) of VC, FVC, FEV1 , FEV1 /FVC, the LLN( P2. 5 ) and the upper limit of normal value ( P97. 5) of FRC, TLC, RV, RV/TLC were calculated. The LLN( P5) of FEV1 /FVC = 101. 924 - 0. 144 × age ( y) - 0. 118 ×high( cm) . The lower normal limit of FEV1 /FVC% pred was 92% . Conclusions This is the first time to have the medical reference of FEV1 /FVC% pred in China, and new prediction equations for DLCO in Shanghai. The LLN of FEV1 /FVC or FEV1 /FVC% pred lt;92% can be used as diagnostic criteria for obstructive ventilation disorder. Instead of using FEV1% pred lt; 80% , FEV1 lt; LLN can be used as diagnostic criteria for mild ventilation disorder.