1、Pulmonary Function Testing,1,PPT學(xué)習(xí)交流,Pulmonary Function Testing,How much air volume can be moved in and out of the lungs How fast the air in the lungs can be moved in and out How stiff are the lungs and chest wall - a question about compliance The diffusion characteristics of the membrane through wh

2、ich the gas moves (determined by special tests) How the lungs respond to chest physical therapy procedures,2,PPT學(xué)習(xí)交流,Evaluating the patient prior to surgery,2,Used for the following reasons,3,PPT學(xué)習(xí)交流,vital capacity,A vital capacity is an important preoperative assessment tool. Significant reductions

3、 in vital capacity (less than 20 cc/Kg of ideal body weight) indicates that the patient is at a higher risk for postoperative respiratory complications. This is because vital capacity reflects the patients ability to take a deep breath, to cough, and to clear the airways of excess secretions.,4,PPT學(xué)

4、習(xí)交流,Contents,Documenting the progression of pulmonary disease - restrictive or obstructive,4,Documenting the effectiveness of therapeutic intervention,Used for the following reasons,5,PPT學(xué)習(xí)交流,Bronchial classification,6,PPT學(xué)習(xí)交流,pulmonary alveoli,RB 呼吸性細(xì)支氣管,AD 肺泡管 A 肺泡,7,PPT學(xué)習(xí)交流,impact factors,gender

5、and body size which have an impact on the lung function of one individual compared to another. Race environmental factors and altitude,8,PPT學(xué)習(xí)交流,9,PPT學(xué)習(xí)交流,Static lung parameter,IRV,ERV,VT,VC,Spirometry,FRC,RV,10,PPT學(xué)習(xí)交流,Terminology and Definitions,FVC - Forced Vital Capacity FEV1 - Forced Expiratory

6、 Volume in One Second FEV1/FVC - FEV1 Percent (FEV1%) - T FEV1/FVC ratio. FEV3 - Forced Expiratory Volume in Three Seconds FEV3/FVC - FEV3% - This number is the ratio of FEV3 to the FVC -,11,PPT學(xué)習(xí)交流,PEFR - Peak Expiratory Flow Rate FEF - Forced Expiratory Flow - Forced expiratory Flow is a measure o

7、f how much air can be expired from the lungs. FEF25%, FEF50%, and FEF75% of FVC. FEF25%-75% - MVV - Maximal Voluntary Ventilation,12,PPT學(xué)習(xí)交流,What Can A PFT Be Used For,Pulmonary function abnormalities can be grouped into two main categories : obstructive defects. restrictive defects.,13,PPT學(xué)習(xí)交流,Obst

8、ructed Airflow,be reduced for a number of reasons ： narrowing of the airways due to bronchial smooth muscle contraction as is the case in asthma narrowing of the airways due to inflammation and swelling of bronchial mucosa and the hypertrophy and hyperplasia of bronchial glands as is the case in bro

9、nchitis material inside the bronchial passageways physically obstructing the flow of air as is the case in excessive mucus plugging, inhalation of foreign objects or the presence of pushing and invasive tumors,14,PPT學(xué)習(xí)交流,destruction of lung tissue with the loss of elasticity and hence the loss of th

10、e external support of the airways as is the case in emphysema external compression of the airways by tumors and trauma,Obstructed Airflow,15,PPT學(xué)習(xí)交流,Restricted Airflow,Extrinsic Restrictive Lung Disorders 1.Scoliosis, Kyphosis2. Ankylosing Spondylitis3.Pleural Effusion (fluid in the pleural cavity)4

11、.Pregnancy5. Gross Obesity6. Tumors7.Ascites8. Pain on inspiration - pleurisy, rib fractures,16,PPT學(xué)習(xí)交流,Neuromuscular Restrictive Lung Disorders 1.Generalized Weakness malnutritio 2. Paralysis of the diaphragm 3.Myasthenia Gravis 4. Muscular Dystrophy 5. Poliomyelitis 6. Amyotrophic Lateral Sclerosi

12、s - Lou Gerigs Disease,Restricted Airflow,17,PPT學(xué)習(xí)交流,Restricted Airflow,Intrinsic Restrictive Lung Disorders 1.Sarcoidosis（結(jié)節(jié)?。?. Tuberculosis（結(jié)核）3.Pnuemonectomy (loss of lung)4. Pneumonia（肺炎）,18,PPT學(xué)習(xí)交流,Criterion for Obstructive and Restrictive Disease,FVC （用力肺活量） In obstructive diseases, the lungs

13、 air volume will be more slowly expelled and will be a smaller volume over the time course of the FVC test than would be expected in a normal, healthy individual. In patients with restrictive lung disease, the FVC will be smaller because the amount of air that can be forcefully inhaled or exhaled fr

14、om the lungs is smaller to start with because of disease.,19,PPT學(xué)習(xí)交流,Criterion for Obstructive and Restrictive Disease,Since FVC will be smaller in obstructive disorders and in restrictive disorders (usually no one worries about the FVC unless it is 80% - 85% of predicted volumes), FVC alone cannot

15、be used to diagnose obstructive and restrictive disorders all by itself,20,PPT學(xué)習(xí)交流,Criterion for Obstructive and Restrictive Disease,The patient may repeat the test after inhaling a bronchodilator. an improved FVC - often times a 10% - 15% improvement.This simple clinical test strongly suggests that

16、 the FVC was low due to obstructive phenomenon. If the FVC did not change, it suggests the FVC was possibly low due to restrictive pathologies.,21,PPT學(xué)習(xí)交流,Another strategy that can help you decide if the low FVC is due to obstructive or restrictive processes is to have the patient perform a Slow Vit

17、al Capacity (SVC) Test. This test is performed by having the patient slowly and completely blow out all of the air from their lungs.,Criterion for Obstructive and Restrictive Disease,22,PPT學(xué)習(xí)交流,F V C,If the vital capacity improves after a SVC test, then it can be assumed that the original small FVC

18、was caused by airway collapse and does not indicate the presence of restrictive disease. If the vital capacity does not improve either with the inhalation of a bronchodilator or does not improve with the administration of a SVC test, then restrictive pathologies must be considered as a possible caus

19、e for the small vital capacity results.,23,PPT學(xué)習(xí)交流,FEV1 FEV1%,FEV1 Healthy individuals to be able to expell 75% - 80 % highly diagnostic of obstructive diseas FEV1% a low FEV1 and the FEV1% is low -obstructive pathologies a low FEV1 and so will the FVC the %FEV1 may well be calculated to be between

20、85% - 100% of normal. -restrictive disease,24,PPT學(xué)習(xí)交流,通氣功能的臨床意義,臨床上常用第1秒用力呼出氣量(FEV1)應(yīng)1.2升,若80%).,FEV1%=FEV1/FVC100,25,PPT學(xué)習(xí)交流,FEF25%- 75%,the presence of obstructive airway disease. the first quarter of the FVC test is in part effected by the patients effort in overcoming the inertial forces which r

21、esist thoracic wall expansion. last quarter of a FVC test is polluted by the patients diminishing physical effort, the instigation of bronchospasm during forced expiration most representative of true expiratory patency and is therefore a very sensitive test for the presence of obstructive disease.,2

22、6,PPT學(xué)習(xí)交流,Dynamic lung parameter,27,PPT學(xué)習(xí)交流,通氣功能的臨床意義,最大呼氣中期流量(MMEF): 將FVC曲線起始至終止兩點(diǎn)平均分為四等分， 取其中間2/4段(MEF75 MEF25)的肺容量與其所用的呼氣時(shí)間之比所得之值, 見下圖 MMEF=AB/CD 單位: L/sec。 MMEF反映的是呼氣的非用力 部分,至一定程度用力時(shí)流量恒 定不變,流量的大小取決小氣 道的直徑,反映了小氣道氣流阻 塞.比FEVF1,FEV1%能靈敏地 反映小氣道阻塞情況.,28,PPT學(xué)習(xí)交流,How Do You Tell If The Patient Is Normal

23、 or Has Mild, Moderate or Severe Pulmonary Disease?,There are a number of systems which physicians use to determine the severity of disease.Here is just one way that is very commonly used : Normal PFT Outcomes - 85 % of predicted values Mild Disease - 65 % but 50 % but 65 % of predicted values Sever

24、e Disease - 50 % of predicted values,29,PPT學(xué)習(xí)交流,The PFT Before and After Aerosol Bronchodilators,Beta-2 selective sympathomimetic （沙丁胺醇） This assesses the degree of reversibility of the airway obstruction. FVC, FEV1 and FEF25% - 75% improve, then it can be said that the patient has a reversible airw

25、ay obstruction FVC : an increase of 10% or more FEV1 : an increase of 200 ml or 15% of the baseline FEV1 FEF25%-75% : an increase of 20% or more,30,PPT學(xué)習(xí)交流,a systematic way to read the PFT,Step 1. Look at the forced vital capacity (FVC) to see if it is within normal limits. Step 2. Look at the forced expiratory vo