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Why do Spirometry?. Farah Madhani-Lovely, MD Pulmonologist/Intensivist Oct 24 th 2007. Objectives. Aware of current guidelines in use of spirometry Understand the use of spirometry in diagnosis of pulmonary disease Understand the use of spirometry in management of pulmonary disease
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Why do Spirometry? Farah Madhani-Lovely, MD Pulmonologist/Intensivist Oct 24th 2007
Objectives • Aware of current guidelines in use of spirometry • Understand the use of spirometry in diagnosis of pulmonary disease • Understand the use of spirometry in management of pulmonary disease • Occupational use of spirometry • Contraindications of spirometry • Introduction to spirometry
Current Guidelines • Lung function testing is a measure of global health • Change in lung function correlates with increased risk of: • Lung Cancer • CAD • CHF • Stroke • Other heart and blood vessel disease Ferguson et al. CHEST 2000;117:1146-1161
Indications • To evaluate symptoms and signs of lung disease • To assess the progression of lung disease • To monitor the effectiveness of therapy • To evaluate preoperative patients • Screen people at risk of pulmonary disease • To monitor for potentially toxic effects of certain drugs/chemicals
Current Guidelines • Early identification of lung abnormalities is related to improved • Smoking cessation rates • Occupational changes • Environmental changes • Vocational changes Ferguson et al. CHEST 2000;117:1146-1161
Diagnosing and management of pulmonary diseases • COPD • Asthma • Restrictive lung disease
COPD • 4th leading cause of death • COPD is the cause of: • 100000 deaths/yr • 550,000 hospitalizations/yr • 16 million hospital visits/yr
Spirometry and COPD • Diagnosis of COPD • Many smokers have quit once knowing their spirometry data • Clotet et al. Archives of bronchology. 2007 • Evaluates prognosis in COPD patients
Facts • Nationally, lung cancer is the leading cause of cancer death among American Indians and Alaska Natives • 1/5 of the deaths in the United States are smoking related. • Cigarette smoking = 10x risk of dying from chronic obstructive lung disease. • Cigarette smoking causes 87 percent of lung cancer deaths and is responsible for most cancers of the larynx, oral cavity and pharynx.
Asthma • Diagnosis of asthma • Guidelines by NHBLI • Measurement of severity of asthma • Response to medications
Restrictive Pulmonary Disease • Extraparenchymal Disease • Chest wall deformity (kyphoscoliosis) • Neurological disorder (myasthenia gravis) • Muscular disease (myopathy) • Abdominal pressure (ascites, obesity) • Pleural Disease (effusion, fibrothorax)
Restrictive Pulmonary Disease • Pulmonary parenchymal disease • Pulmonary fibrosis • Pneumoconiosis • Granulomatous dz(Sarcoidosis) • Vasculitis
Occupational screening • Lung disease associated with occupation • Lung cancer • Occupational asthma • Asbestosis • Mesothelioma • Byssinosis • Coal workers’ pneumoconiosis • Silicosis • Hypersensitivity pneumonitis
Contraindications • Patient in respiratory isolation • Inability to cooperate or sit up straight • Acute illness • Acute coronary syndrome • Pneumonia • Chest pain • Current tracheostomy
Clinic set up • Accurately measure FEV1 and FVC • Daily caliberation • Quality control • Must be acceptable • Must be reproducible
Spirometry • Measurement of air movement in and out of the lung during different respiratory maneuvers. • Values measured are: • FVC: Forced Vital Capacity • FEV1: The forced expiratory volume in one second • MVV: Maximum Voluntary Ventilation
FEV1 & FVC • Forced expiratory volume in 1 second • 4.0 L • Forced vital capacity • 5.0 L • usually less than during a slower exhalation • FEV1/FVC = 80% FEV1 FVC
Unacceptable spirometry Uptodate.com
Obstructive Airway Disease • Obstruction • FEV1 < 80% predicted • FEV1/FVC < 70%
Restrictive Lung Disease • VC, FRC, TLC < 80% • FEV1/FVC = Normal • Pseudorestriction • NMDz • Obesity
FLOW-VOLUME CURVE in respiratory patients • Restrictive disease • expansion of the lung • e.g., interstitial fibrosis • Obstructive disease • resistance to airflow • e.g., COPD, asthma FEV1 FVC
Summary • Spirometry is used to diagnose and manage patients with: • COPD • ASTHMA • OCCUPATIONAL LUNG disease • Knowledge of lung function helps in smoking cessation • Spirometry i.e. lung function is an assessment of global health