临床肺功能检查PFT-MED

Testing Guidelines
Spirometry
• Forceful expiration, no hesitation, at least 6 seconds • At least 3 acceptable maneuvers obtained • Two largest FVC and FEV1 values within 150 ml • Best test = largest FVC + FEV1
Water-seal spirometer: 水鼓式
Pneumotach 流速仪
Portable spirometer 便携式
Portable spirometer 动态肺量计
Body box 体描箱
Diffusion
What Information Does PFT Provide ?
Interpretation of Pulmonary Function Testing
Step 1. Examine flow-volume loop
• • • • • Is it a good PFT’s? Is it normal? Characteristic pattern of obstruction? Pattern of restriction? Pattern of upper airway obstruction?
Case 5
ZXM 39 y/o female, non-smoker, cough and wheezing 10 days, worsening at night, asthma suspected. Normal physical exam.
How to interpret the test?
Case 7
RS 50 y/o male, 170 cm, 64 kg history of COPD, referred for LVRS
Case 7
Case 7
Pred FVC FEV1 FEV1% TLC RV DLCO 4.43 3.30 74 6.45 2.02 27.8 PRE 1.79 0.63 35 %Pred POST %Pred %Chg 40 19 2.74 0.92 34 6.79 3.75 62 28 105 185 53 46 -3
C源自文库se 3
How to interpret the test?
Case 3
Meas 1.12 1.04 93 2.09 9 % 19 21 28 26
FVC FEV1 FEV1% TLC DLCO
Ref 6.01 4.89 81 7.45 35
Case 4
BKM 25 y/o male, non-smoker, cough for 1 month, denied shortness of breath or wheezing. Normal physical exam.
Pulmonary Function Tests
临床肺功能检查
What Pulmonary Function Tests Do You Need ?
• • • • • Spirometry Lung Volumes Body Plethysmography Diffusing Capacity (DLCO) Arterial Blood Gas Analysis
Lung Volumes
Indications
• Diagnose / assess restrictive lung disease • Assess hyperinflation in obstructive disease • Assess response to treatment
– Lung transplantation – Lung volume reduction – Radiation, chemotherapy
Case 1
How to interpret the test?
Case 1
Meas 3.02 1.23 41 3.95 % 88 49 65
FVC FEV1 FEV1% PEF
Ref 3.41 2.53 74 6.10
Case 2
A 55 year old male was evaluated preoperatively for cataract surgery.
Criteria for Restriction
• Reduced TLC is a Golden standard • Reduced FVC with normal FEV1/FVC ratio is sensitive but lacks of specificity
Nonspecific Ventilation Limitation
Case 6
SW 58 y/o female, 160 cm, 84 kg referred for dyspnea on exertion
1) Difficulty to perform spirometry 2) Audible stridor during expiration
Case 6
Normal Flow-Volume Loop
Cough
Variable Effort
Severe Obstruction
Restriction
Upper Airway Obstruction
Step 2. Are the data consistent with flow-volume loop?
• • • • Reduced FVC and FEV1 Normal FEV1/FVC Normal TLC Restrictive? Obstructive?
Step 3. Examine the response to bronchodilation
• FEV1:
• 12% or more increase and 200ml increase
Case 4
%Change 15% 14%
FVC FEV1 FEV1%
Bronchodilator Test Pre Post 4.43 5.08 3.61 4.10 74 79
Can you make a statement as to the patient’s underlying lung disease?
Case 7
What therapy do you suggest based on the results of PFT?
Summary
• Pulmonary function tests are valuable for the assessment of lung diseases. By ensuring proper calibration of equipment and performance of test maneuvers, one can differentiate among several different diseases.
Three times daily recordings of spirometry
120
Percent of the predicted value (%)
100 80 60 40 20 0 0 2 4 6 8 Day 10 12 14
FEV1
PEF
Case 5
• • • • • Obstruction based on a reduced FEV1% Recurrent morning falls in FEV1 and PEF PEF variability 68% Substantial improvement with treatment Final diagnosis of asthma
Order a chest x-ray
Case 4
How to interpret the test?
Case 4
Meas 4.43 3.61 74 % 84 81
FVC FEV1 FEV1%
Ref 5.25 4.44 86
How to interpret bronchodilator test?
Case 5
Meas 4.20 2.26 66 % 127 79
FVC FEV1 FEV1%
Ref 3.32 2.86 86
Case 5
• Portable spirometry for 14 days • Tulobuterol patch 2mg QD for 14 days
Portable spirometry 动态肺量测定
8.9
32
How would you interpret the test?
Case 7
• The patient has severe obstruction based on a markedly decreased FEV1/FVC ratio. • Significant hyperinflation is present with an increased RV. • The reduced DLCO suggests the presence of anatomic emphysema • There is a significant response to bronchodilator
• • • • The function of the airways The function of pulmonary parenchyma Pulmonary vasculature Respiratory muscle
Spirometry
Indications
• • • • Detect lung disease (screening) Quantify extent of known disease Determine benefits/risks of therapy Assess surgical risk
• sGaw*:
• 30-40% or more increase
* Chest 1992; 101:1572-1581
Step 4. Lung volume, diffusion and others
Case 1
A 60 year old female was evaluated for dyspnea on exertion .
Case 2
How to interpret the test?
Case 2
Meas 1.85 0.92 50 3.82 % 40 28 45
FVC FEV1 FEV1% PEF
Ref 4.60 3.33 72 8.55
Case 3
30 y/o male, 186 cm, 68 kg, severe interstitial fibrosis.
Case 6
Case 6
Ref FVC FEV1 FEV1% TLC RV RV/TLC% DLCO Pre % Post % 79 23 %Change 0 -57 -57 3.00 2.39 80 2.38 2.22 1.18 53 0.51 74 49 21 4.73 4.03 85 1.72 1.64 95 37 41 Could not be performed
• FVC (VC): an expression of lung size • FEV1: influenced by lung size and the dimensions of airway • FEV1/FVC: a measure of airway obstruction • Reduced FVC with normal FEV1/FVC only suggests restriction. TLC is indicated to confirm the restriction
Diffusion Capacity
Indications
• Follow progress of interstitial lung disease • Assess pulmonary involvement in systemic disease • Evaluate gas exchange in obstructive disease • Assess pulmonary vascular diseases