690 likes | 1.07k Views
Usage of Pulmonary Function Tests in Clinic Except Spirometry Diffusion Capacity. Prof.Dr.Birsen MUTLU I.U.Cerrahpasa Medical Faculty Department of Pulmonary Diseases. Pulmonary Function Tests Application Field. 1-Diagnosis and treatment of Lung and Heart diseases
E N D
Usage of Pulmonary Function Tests in Clinic Except Spirometry Diffusion Capacity Prof.Dr.Birsen MUTLU I.U.Cerrahpasa Medical Faculty Department of Pulmonary Diseases
Pulmonary Function Tests Application Field 1-Diagnosis and treatment of Lung and Heart diseases 2-Preoperative evaluation 3-Evaluation of disability 4-Epidemiologic studies for the evaluation of industrial diseases 5-Simple determination of disease incidence in a given population
-Alveols -Airways (Ventilation) -Capillary network (perfusion)
-Ventilation -Distribution -Diffusion -Perfusion
Pulmonary Function Tests A- Airway function 1.Simple spirometry Vital capacity(VC),expiratory reserve volume (ERV), inspiratory capacity (IC) 2.Forced vital capacity maneuver a-FVC,FEV1,FEF,PEF (1)Prebronchodilator and postbronchodilator (2)Prebronchochallenge and postbronchochallenge b-MEFV curves,Vmaxx (1)Prebronchodilator and Postbronchodilator (2)Prebronchochallenge and postbronchochallenge
3.Maximal voluntary ventilation (MVV) 4.Maximal inspiratory/expiratory pressures (MIP/MEP) 5.Airway resistance (Raw) and Compliance (C)
B-Lung volumes and ventilation 1.Functional residual capacity (FRC) a.Open-circuit (N2 washout) b.Closed-circuit/rebreathing ([He dilution) c.Thoracic gas volume (VTG) 2.Total lung capacity (TLC),residual volume (RV),RV/TLC ratio 3.Minute ventilation,alveolar ventilation and dead space 4.Distribution of ventilation a.Multiple-breath N2 b.He equilibration c.Single-breath techniques Pulmonary Function Tests
Pulmonary Function Tests C- Diffusion capacity tests 1. Single-breath(breath holding) 2. Steady state 3. Other techniques
Pulmonary Function Tests D-Blood gases and gas exchange tests 1.Blood gas analysis 2. Pulse oximetry 3. Capnography
Pulmonary Function Tests E- Cardiopulmonary exercise tests 1. Simple noninvasive tests 2. Tests with exhaled gas analysis 3. Tests with blood gas analysis F- Metabolic measurements
DIFFUSION This is an electrochemical event between gas and liquid. Occurs due to the partial pressure difference of the gases.
DIFFUSION CAPACITY Amount of gas (mL) passed through the capillary membrane in a given time(1min) and in a given pressure difference (1mmHg) (mL/min/mmHg)
DIFFUSION VELOCITY V=A.k.α.(P1-P2) h V=Diffusion velocity within a given time A=Diffusion surface area k=diffusion constant α=gas solubility P1-P2= Partial pressure difference of two environment that the diffusion takes place in. h=membrane thickness
Factors that effect diffusion velocity -k (diffusion constant) -Α (solubility) -Viscosity of diffusion milieu Air diffusion velocity>water diffusion velocity *Tissue diffusion velocity = fluid diffusion velocity *Exclusion: Erythrocyte hb concentration viscosity diffusion velocity
-CO is the standart gas that used in diffusion measurements -It has high Hgb. affinity -The only factor that limits CO diffusion is alveolocapillary membrane
ERS (1993) TLCO:Transfer factor ATS (1995) DLCO:Diffusion capacity DLCO=mL/dak/mmHg TLCO=mmoL/dak/kPa DLCO/TLCO =3:1 DLCO x O.33=TLCO
Diffusion ventilation ratio ERS TLCO/VA (=KCO)Transfer coefficient ATS DLCO/VA (mL/dak/mmHg)
Methods used in diffusion measurement 1-Single-breath holding 2-Single expiration 3-Rebreathing 4-Steady state 5-Riley-Lilienthal 6-VA/Q 7-Single breath oxygen holding
Resting DLCO:25 mLCO/min/mmHg %81-140 (predicted)=>normal %61-80 (predicted)=>mild decrease %41-60 (predicted)=>moderate <%40 (predected)=>significantly decreased
Factors that effect DLCO measurement 1-Age,height,body surface area 2-Cigarette smoking 3-Hemoglobin level 4-Body position and exercise 5-Lung volumes 6-Inspiration and expiration maneuver
Factors that effect DLCO measurement 7-Altitude 8-Oxygen concentration 9-Diurnal distribution 10-Menstrual cycle 11-Drinking alcohol 12-Sex and marital status
Age, height, body surface area in children DLCO *Age in elderly DLCO * Body surface area, height, DLCO muscle structure *Weight has no effect
Cigarette smoking Chronic cigarette smoking DLCO and KCO Acute smoking, Occupational CO exposure alveolar CO pressure Frequently repeated test *Decreased measurement due to smoking is maksimum 10%. *Must stop smoking at least 24 hours earlier *Modification must be done in frequent smokers
Hemoglobin level Hb DLCO Hb DLCO -1 gram change in Hgb will change DLCO 7% -Measured DLCO value: Standardized due to Hgb:14.6g/dL -DLCO must be corrected due to changes in Hgb
Body position and exercise -In dawnward position the difference is %5-30 -In upright position *Reason:During positional changes pulmonary blood volume -During exercise *In active persons DLCO and DLCO/VA
Lung Volumes Volumes DLCO To detect actual diffusion loss ; DLCO/VA (KCO) must be used
Inspiration and Expiration Maneuvers Valsalva maneuvers Muller effect intrathoracic pressure
Altitude Altitude FIO2 DLCO *Correction may be necessary Oxygen concentration There is negative correlation between PAO2 and DLCO * No O2 supplemantationduring test
Diurnal alteration DLCO reaches Peak level in the morning *During daytime progressively ~(1-2%) per hour Menstrual cycle and parity -~13% change during cycle (Changes are due to Hgb effect) -No significant change during parity
Alcohol drinking 15-30ml 95% alcohol will decrease DLCO 15% after 90 minutes Sex and ethnic condition DLCO in men > women DLCO whites > blacks
CLINICAL USAGE Decrease in DLCO ASSOCIATED WITH: 1-Obstructive lung diseases Emphysema Cystic fibrosis 2-Parenchymal diseases Interstitial pneumonia Extrinsic allergic alveolitis Viral pneumonia Chronic interstitial fibrosis (silicos) Bronchioalveolar lung cancer Drug reaction(bleomycin,nitrofurantoin) Alveolar proteinous and microlithyasis Lymphangioleiomyomatosis
3-Systemic diseases effecting lung -Sarcoidosis -Disseminated tuberculosis -Progressive systemic sclerosis -RA -SLE -Mixed Connective Tissue Diseases -Dermatomyositis-Polymyositis -Wegener granulomatosis -Inflammatory intestinal diseases
4-Cardiopulmonary diseases -PPH -TEAH -Lung edema -Mitral stenosis -Acute MI 5-Othere causes -Anemia -CRF -Chronic hemodialysis -BOOP -Cocaine,marijuana -Acute and chronic alcohol drinking -Cigarette smoking
FACTORS DECREASING DLCO WHICH ARE INDEPENDENT FROM OTHER VENTILATORY PARAMETERS -Interstitial diseases that don’t effect airflow -Pulmonary venoocclusive diseases -Inflamatory diseases -Microembolism
DLCO/VA:N -restriction DLCO -parenchymal changes DLCO/VA: -obstruction -dead space
Initially (upper field blood flow cardiac output ) After progression: (V/Q equilibrium disturb) ASTHMA
CONGESTIVE HEARTH FAILURE Initially (dilatation of pulmonary vessels) After lung edema
-Resection surgery DLCO -VAC DLCO -Bullectomy
DISEASES INCREASING DLCO 1-Diseases involve polystemia 2-Alveolar haemorhage:Good Pasture syndrome 3-Increased pulmonary blood volume:left-right intracardiac shunts 4-In Asthma, generally N During attack
Diseases not effecting DLCO 1-Chest diseases 2-Pleura 3-Asthma 4-Bronchitis 5-Localised pulmonary lesions 6-Neurofibrotic pneumoconiosis
DLCO Decreased Increased DLCO/VA NORMAL DECREASED -ALVEOLAR HAEMORRHAGE -POLYSTEMIA - DECREASE IN PULMONARY BLOOD VOLUME -DECREASED LUNG VOLUME -PARENCHYMAL DESTRUCTION -OBSTRUCTION -INCREASED DEAD SPACE
Indications of Diffusion Capacity 1-Evaluation of parenchymal lung diseases -organic and inorganic dust -drugs and lung 2-Systemic diseases involve lung -RA -Sarcoidosis -SLE -Systemic sclerosis -Mixed connective tissue diseases
3-Obstructive lung diseases -Differential diagnosis(asthma- COPD) -Disease progression follow-up -Calculation of desaturation during exercise in COPD 4-Cardiovascular diseases -PPH -TELD -Lung edema
5-Quantification of disability in interstitial lung diseases 6-Detection of factors that increase DLCO -polystemia -pulmonary haemorrhage -left-right intracardiac shunt 7-Prediction of postoperative functional condition for preoperative evaluation
1 FEV1/FVC>%70 NO YES 3 2 FEV1>%80 FEV1>%80 Flow-Volume curve NO YES NO YES 4 TLC TLC YES YES NO NO Restriction Obstruction Mixed defect Normal ? 5 DLCO DLCO DLCO NO YES NO YES NO YES Normal PV disease Thoracic cavity and NM disease ILD and Int pneumonia Asthma and chronic bronchitis COPD and emphysema
FEV1/FVC>%70 YES NO FEV1>%80 FEV1>%80 NO YES NO YES TLC TLC YES YES NO NO Restriction Obstruction Mixed defect Normal ? DLCO DLCO DLCO YES NO NO YES NO YES Normal PV disease Thoracic cavity and NM diseases ILD ve Int pneumonia Asthma and chronic bronchitis COPD and Emphysema
DIFFUSSION CAPACITY 4.13