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Pulmonary Function Tests Ventilatory Function – Spirometry Clinical Applications Clinical Applications

LUNG FUNCTION TESTS Tests of Ventilation Tests of Ventilation Tests of Diffusion Tests of Diffusion Tests of Perfusion Tests of Perfusion Tests for V-P Mismatch Tests for V-P Mismatch

LUNG FUNCTION TESTS Tests of Ventilation Tests of Ventilation Tests of Diffusion Tests of Diffusion Tests of Perfusion Tests of Perfusion Tests for V-P Mismatch Tests for V-P Mismatch

Function of Ventilation Air Exit – Airways, Bronchomotor tone, Secretions, Thoracic muscles etc Air Exit – Airways, Bronchomotor tone, Secretions, Thoracic muscles etc Air Entry – Expansion of lungs – Functioning lung volume, its elastic nature, Lung compliance Air Entry – Expansion of lungs – Functioning lung volume, its elastic nature, Lung compliance ‘Air Out’ Problem – Obstructive Diseases ‘Air Out’ Problem – Obstructive Diseases ‘Air In’ problem – Restrictive Diseases ‘Air In’ problem – Restrictive Diseases Both Air Out and In - Combined Both Air Out and In - Combined

Objectives  To detect Obstructive Airway Diseases  To quantify the severity of obstruction.  To assess response to IBD.  To identify Restrictive Lung Diseases.  To identify flow-volume loop patterns  To understand the clinical relevance. Spirometry

PEAK FLOW METER Diagnosis of ASTHMA or COPD can be confirmed by demonstrating the presence of airway obstruction using Spirometry.

PEFR - Pros and Cons Advantages Advantages With in 1 to 2 minutes, With in 1 to 2 minutes, Inexpensive (meter costs less than Rs.1000) Inexpensive (meter costs less than Rs.1000) Simple, useful for frequent follow up use Simple, useful for frequent follow up use Disadvantages Disadvantages Very much effort dependent Very much effort dependent Insensitive to small changes Insensitive to small changes Small airways cannot be assessed Small airways cannot be assessed Large inter & intra subject variation; ↓ accurate Large inter & intra subject variation; ↓ accurate

SPIROMETRY

SPIROMETRY

SPIROMETRY

SPIROMETRY

Spirometry - Pros and Cons Advantages Advantages Evaluates smaller as well as larger airways Evaluates smaller as well as larger airways Relatively easy to use and maintain Relatively easy to use and maintain Reversibility can be tested with IBD and steroids Reversibility can be tested with IBD and steroids Diagnostic as well as management assessments Diagnostic as well as management assessments Disadvantages Disadvantages Costs about 50,000 + computer and printer Costs about 50,000 + computer and printer Takes time to perform – 10 to 15 minutes Takes time to perform – 10 to 15 minutes Requires training – at least one day course Requires training – at least one day course

Spirometry Maneuver In single breath test A few normal tidal respirations A few normal tidal respirations Then deeeeep inspiration Then deeeeep inspiration Momentary breath holding Momentary breath holding Very forced and fast expiration Very forced and fast expiration As hard and as fast as he/she can blow out As hard and as fast as he/she can blow out Then deep, quick and full inspiration Then deep, quick and full inspiration Repeat at least 3 times – take the best Repeat at least 3 times – take the best

Reproducibility of Spirometry Adequate explanation to the patient Adequate explanation to the patient Demonstrating the steps one by one Demonstrating the steps one by one Encouraging the patient to give best effort Encouraging the patient to give best effort Taking at least 3 and usually 5 attempts Taking at least 3 and usually 5 attempts Selecting the best effort Selecting the best effort Cough and severe dyspnoea may interfere Cough and severe dyspnoea may interfere Not like ECG – Results depend on effort Not like ECG – Results depend on effort

Spirometry Results FVC Forced Vital Capacity FVC Forced Vital Capacity FEV 1 Forced Expiratory Volume in the first second FEV 1 Forced Expiratory Volume in the first second FEV 1 /FVC Ratio of the above two FEV 1 /FVC Ratio of the above two PEFRPeak Expiratory Flow Rate PEFRPeak Expiratory Flow Rate FETForced Expiratory Time FETForced Expiratory Time

Normal Flow-Volume Volume-Time Test Values

Spirometry Results FVC Forced Vital Capacity FVC Forced Vital Capacity FEV 1 Forced Expiratory Volume in the first second FEV 1 Forced Expiratory Volume in the first second FEV 1 /FVC Ratio of the above two FEV 1 /FVC Ratio of the above two PEFRPeak Expiratory Flow Rate PEFRPeak Expiratory Flow Rate FETForced Expiratory Time FETForced Expiratory Time

Spirometry Normal Values 1. There are no fixed ‘Normal’ values 2. Dependent on age, sex, height, weight, ethnicity 3. Observed value expressed as % of predicted value FVC Normal if > 80% of predicted FVC Normal if > 80% of predicted FEV1Normal if > 80% of predicted FEV1Normal if > 80% of predicted FEV1/FVC At least 75% FEV1/FVC At least 75% PEFRNormal if > 80% of predicted PEFRNormal if > 80% of predicted FETLess than 4 seconds FETLess than 4 seconds

The Four Square Game FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. 80%

The Four Square Game FVC NORMALFVC < 80% Pred. 80% Normal Lungs FEV 1 ÷FCV is N FEV 1 NORMAL FEV 1 < 80% of Pd.

The Four Square Game FVC NORMALFVC < 80% Pred. 80% FEV 1 NORMAL FEV 1 < 80% of Pd. Obstructive Disease FEV 1 ÷FCV is Low

The Four Square Game FVC NORMALFVC < 80% Pred. 80% FEV 1 NORMAL FEV 1 < 80% of Pd. Restrictive Disease FEV 1 ÷FCV is High

The Four Square Game FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. 80% Combined Obs+Res FEV 1 ÷FCV is N or L

The Four Square Game FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. 80% Normal Lungs FEV 1 ÷FCV is N Obstructive Disease FEV 1 ÷FCV is Low Restrictive Disease FEV 1 ÷FCV is High Combined Obs+Res FEV 1 ÷FCV is N or L

The Four Square Game FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. 80% Normal Air Entry & Exit Air Exit Problem Airways choked Air Entry Problem Lungs ↓ expansion Both Air Entry & Air Exit Problem

The Four Square Game FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. 80% Normal Lungs FEV 1 ÷FCV is N Obstructive Disease FEV 1 ÷FCV is Low Restrictive Disease FEV 1 ÷FCV is High Combined Obs+Res FEV 1 ÷FCV is N or L

Millers Prediction Quadrants FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. Air In and Out N Normal Lungs FEV 1 ÷FCV is N Air Exit is chocked Obstructive Disease FEV 1 ÷FCV is Low Air Entry is reduced Restrictive Disease FEV 1 ÷FCV is High Both Air In & Out ↓↓ Combined Obs+Res FEV 1 ÷FCV is N or L 90%100% 70%80%60% 90% 100% 70% 60%

Algorithm for Diagnosis FVC FVC > 80% FVC < 80% FEV1 > 80%FEV1 < 80% Normal PFTObstructive Reversible IrreversibleExtra-pulmonary FEV1 < 80%FEV1 > 80% RestrictiveCombined Pulmonary IBD

Normal Airways and Lungs FVC > 80% FVC > 80% FEV 1 > 80% FEV 1 > 80% FEV 1 ÷FCV> 75% FEV 1 ÷FCV> 75% PEFR> 80% PEFR> 80% FET<4 sec FET<4 sec Air Entry Normal Air Entry Normal Air Exit Normal Air Exit Normal FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75%

Normal Airways - PFT

Normal PFT and CXR

Bronchial Asthma – Reversible Airway obs. Bronchial Asthma – Reversible Airway obs. Chronic bronchitis – Irreversible with IBD Chronic bronchitis – Irreversible with IBD Emphysema – Irreversible with IBD Emphysema – Irreversible with IBD Bronchiectasis – Airway rigidity Bronchiectasis – Airway rigidity Cystic Fibrosis Cystic Fibrosis Allergic bronchopulmonary Aspergillosis Allergic bronchopulmonary Aspergillosis Bronchiolitis Bronchiolitis Obstructive Airways Disease

Obstructive Airways Disease FVC > 80% FVC > 80% FEV 1 < 80% FEV 1 < 80% FEV 1 ÷FCV< 75% FEV 1 ÷FCV< 75% PEFR< 80% PEFR< 80% FET>4 sec FET>4 sec Air Entry Normal Air Entry Normal Air Exit Problem Air Exit Problem FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75%

Obstructive Airways Disease - PFT FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75%

Obstructive V/s Normal

Obstructive Airways Mild Bronchial Asthma

Bronchial Asthma Reversible Obstruction (IBD)

Bronchiectasis (Obstructive) BRONCHOGRAM - BIL UNILATERAL

Obstructive Airways Severe Emphysema

Obstructive Airways Severe -IBD Emphysema

Obstructive Lung Diseases ABPACYSTIC FIBROSIS

Upper Airway Obstruction Truncation of flow loop Truncation of flow loop Expiratory – Intra Thoracic Expiratory – Intra Thoracic Inspiratory –Extra Thoracic Inspiratory –Extra Thoracic Both – Fixed Obstruction Both – Fixed Obstruction Tumour Tumour Tracheal stenosis Tracheal stenosis Tracheal FB Tracheal FB Vocal Chord Dysfunction Vocal Chord Dysfunction

Restrictive Lung Diseases Sarcoidosis Sarcoidosis Tuberculosis – (Fibrocaseous) Tuberculosis – (Fibrocaseous) Interstitial Lung Disease - ILD Interstitial Lung Disease - ILD Idiopathic pulmonary fibrosis - IPF Idiopathic pulmonary fibrosis - IPF Pneumoconiosis Pneumoconiosis Drug- or radiation-induced lung disease Drug- or radiation-induced lung disease Pneumonectomy Pneumonectomy

Extrinsic Restrictive Diseases Kyphosis, Scoliosis Kyphosis, Scoliosis Ankylosing Spondylitis Ankylosing Spondylitis Massive Pleural effusion Massive Pleural effusion Pregnancy, Obesity, Ascites Pregnancy, Obesity, Ascites Rib fractures Rib fractures Neuromuscular disorders Neuromuscular disorders

Restrictive Lung Disease FVC < 80% FVC < 80% FEV 1 > 80% FEV 1 > 80% FEV 1 ÷FCV> 75% FEV 1 ÷FCV> 75% PEFR> 80% PEFR> 80% FET<4 sec FET<4 sec Air Entry Problem Air Entry Problem Air Exit Normal Air Exit Normal FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75%

Restrictive Lung Disease - PFT FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75% ILD or IPF

Restrictive V/s Normal ILD or IPF

ILD or IPF Restrictive Lung Disease - ILD

Restrictive Lung Disease - ILD HEPATIOD APPEARANCE

Restrictive Lung Disease - ILD RETICULAR PERIPHERIES

Restrictive Lung Disease - ILD HRCT ChestX-RAY CHEST - ILD

Restrictive Lung Diseases SARCOIDOSIS RETICULO-NODULAR

Combined Obstructive + Restrictive FVC < 80% FVC < 80% FEV 1 < 80% FEV 1 < 80% FEV 1 ÷FCV< 75% FEV 1 ÷FCV< 75% PEFR< 80% PEFR< 80% FET>4 sec FET>4 sec Air Entry Problem Air Entry Problem Air Exit Problem Air Exit Problem FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75%

Combined Obstructive + Restrictive FEV1 is LOW FVC is Normal FEV1 ÷ FVC is < 75%

Combined Obstructive + Restrictive KOCHS + EMPHYSEMA

Other Patterns FIXED OBSTRUCTION

Other Patterns EXTRA THORACIC COUGH

Case 1 TestPred.Meas.% FVC 5.5 L 4.5 L 82% FEV1 4.9 L 3.0 L 61% Ratio89%66%- Man, aged 28, 172cm, 71kg Non smoker, Cough 3 M

Case 1 Man, aged 28, 172cm, 71kg Non smoker, Cough 3 M Dx : Bron Asthma - Rev IBD Good ResponseTestPred.Meas.%FVC 5.5 L 4.5 L 82% FEV1 4.9 L 3.0 L 61% Ratio89%66%-

Case 2 Woman, 48 y, 155cm, 47 kg Non smoker, Dysp., CP TestPred.Meas.% FVC 3.9 L 2.6 L 66% FEV1 3.1 L 2.4 L 78% Ratio79%92%-

Case 2 Woman, 48 y, 155cm, 47 kg Non smoker, Dysp., CP Diagnosis : # Ribs 5,6,7,8 TestPred.Meas.% FVC 3.9 L 2.6 L 66% FEV1 3.1 L 2.4 L 78% Ratio79%92%-

Case 3 TestPred.Meas.% FVC 6.0 L 5.0 L 83% FEV1 4.8 L 4.1 L 85% Ratio80%82%- Man 35, 175cm, 75kg, MC Non smoker, Clinical N

Case 3 TestPred.Meas.% FVC 6.0 L 5.0 L 83% FEV1 4.8 L 4.1 L 85% Ratio80%82%- Man 35, 175cm, 75kg, MC Non smoker, Clinical N Diagnosis : Normal PFT

Case 4 Child, 8 y, 128 cm, 19 kg Stridor, Dysp G3, BS Decr. TestPred.Meas.% FVC 1.9 L 0.7 L 36% FEV1 1.6 L 0.4 L 25% Ratio84%57%-

Case 4 Child, 8 y, 128 cm, 19 kg Stridor, Dysp G3, BS Decr. TestPred.Meas.% FVC 1.9 L 0.7 L 36% FEV1 1.6 L 0.4 L 25% Ratio84%57%- FB in the UAW

Case 5 Woman, 29 y, 160cm, 41 kg Had ATT, Dysp G3, Wheeze TestPred.Meas.% FVC 3.5 L 1.8 L 51% FEV1 2.8 L 1.2 L 43% Ratio80%66%-

Case 5 Diagnosis : TB + ABPA TestPred.Meas.% FVC 3.5 L 1.8 L 51% FEV1 2.8 L 1.2 L 43% Ratio80%66%- Woman, 29 y, 160cm, 41 kg Had ATT, Dysp G3, Wheeze

Case 6 Man, aged 58, 165cm, 51kg Smoker 16yr, Severe Dysp.TestPred.Meas.%FVC 4.5 L 3.7 L 82% FEV1 3.6 L 1.8 L 50% Ratio80%49%-

Case 6 Man, aged 68, 165cm, 51kg Smoker 16yr, Severe Dysp. DX :COPD- IrreversibleTestPred.Meas.%FVC 4.5 L 3.7 L 82% FEV1 3.6 L 1.8 L 50% Ratio80%49%- IBD NO Response

The Four Square Game FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. 80% Normal Lungs FEV 1 ÷FCV is N Obstructive Disease FEV 1 ÷FCV is Low Restrictive Disease FEV 1 ÷FCV is High Combined Obs+Res FEV 1 ÷FCV is N or L

Millers Prediction Quadrants FEV 1 NORMAL FEV 1 < 80% of Pd. FVC NORMALFVC < 80% Pred. Air In and Out N Normal Lungs FEV 1 ÷FCV is N Air Exit is chocked Obstructive Disease FEV 1 ÷FCV is Low Air Entry is reduced Restrictive Disease FEV 1 ÷FCV is High Both Air In & Out ↓↓ Combined Obs+Res FEV 1 ÷FCV is N or L 90%100% 70%80%60% 90% 100% 70% 60%

Take Home Points All that wheezes is not Asthma only All that wheezes is not Asthma only All Dyspnoea does not wheeze All Dyspnoea does not wheeze Do not over simplify dyspnoea to Deriphyllin Do not over simplify dyspnoea to Deriphyllin Etiology of Dyspnoea needs elucidation Etiology of Dyspnoea needs elucidation Spirometry tests but Ventilation function only Spirometry tests but Ventilation function only Need to test diffusion, Perfusion functions Need to test diffusion, Perfusion functions Cardiac, Hematologic and other causes