Why do Spirometry? - AFHCAN Telehealth Solutions

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Transcript Why do Spirometry? - AFHCAN Telehealth Solutions

Why do Spirometry?
Farah Madhani-Lovely, MD
Pulmonologist/Intensivist
Oct 24th 2007
Objectives
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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
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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
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Ferguson et al. CHEST 2000;117:1146-1161
Indications
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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
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Early identification of lung abnormalities is
related to improved
Smoking cessation rates
 Occupational changes
 Environmental changes
 Vocational changes
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Ferguson et al. CHEST 2000;117:1146-1161
Diagnosing and management of
pulmonary diseases
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COPD
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Asthma
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Restrictive lung disease
COPD
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4th leading cause of death
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COPD is the cause of:
100000 deaths/yr
 550,000 hospitalizations/yr
 16 million hospital visits/yr
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Spirometry and COPD
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Diagnosis of COPD
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Many smokers have quit once knowing their
spirometry data
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Clotet et al. Archives of bronchology. 2007
Evaluates prognosis in COPD patients
Symptom Improval
COPD
Spirometry test
Signs
At risk
Normal
Chronic cough
Mild
Mild airflow
obstruction
Worsening airflow
obstruction
Severe airflow
obstruction
May be aware
Moderate
Severe
Symptoms with
physical activity
Symptoms with
ADLs
FEV1 Scale
COPD Risk and Smoking Cessation
Facts
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Nationally, lung cancer is the leading cause of cancer
death among American Indians and Alaska Natives
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1/5 of the deaths in the United States are smoking
related.
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Cigarette smoking = 10x risk of dying from chronic
obstructive lung disease.
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Cigarette smoking causes 87 percent of lung cancer
deaths and is responsible for most cancers of the
larynx, oral cavity and pharynx.
Lung Cancer Distribution
Population
% of Lung Ca
Native Americans/Alaska Natives
33.4%
Caucasian
22.2%
African Americans
20.2%
Hispanic
15.3%
Asian Americans
11.3%
Asthma
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Diagnosis of asthma
Guidelines by NHBLI
 Measurement of severity of asthma
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Response to medications
Classification of Asthma
Severity
For adults and children >5 years
old who can use a spirometer or
peak flow meter
Classification
Days with
Step Symptoms
Nights with
Symptoms
FEV1 or PEF*
% Predicted Normal
PEF
Variability
Severe
Persistent
4
Continual
Frequent
<60%
>30%
Moderate
Persistent
3
Daily
>5/month
>60% to <80%
>30%
Mild
Persistent
2
>2/week
3–4/month
>80%
20% to
30%
Mild
1
<2/week
<2/month
Intermittent
*FEV1- Forced Expiratory volume in 1 second
*PEF- Peak Expiratory Flow
>80%
<20%
Restrictive Pulmonary Disease
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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
 Pulmonary
parenchymal disease
fibrosis
 Pneumoconiosis
 Granulomatous dz(Sarcoidosis)
 Vasculitis
Occupational screening
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Lung disease associated with occupation
Lung cancer
 Occupational asthma
 Asbestosis
 Mesothelioma
 Byssinosis
 Coal workers’ pneumoconiosis
 Silicosis
 Hypersensitivity pneumonitis
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Contraindications
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Patient in respiratory isolation
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Inability to cooperate or sit up straight
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Acute illness
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Acute coronary syndrome
Pneumonia
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Chest pain
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Current tracheostomy
Clinic set up
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Accurately measure FEV1 and FVC
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Daily caliberation
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Quality control
Must be acceptable
 Must be reproducible
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Spirometry
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Measurement of air movement in and out of
the lung during different respiratory maneuvers.
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Values measured are:
FVC: Forced Vital Capacity
 FEV1: The forced expiratory volume in one second
 MVV: Maximum Voluntary Ventilation
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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
Coaching a patient
Unacceptable spirometry
Uptodate.com
Spirometry in different lung diseases
Obstructive Airway Disease
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Obstruction
 FEV1
< 80% predicted
 FEV1/FVC
< 70%
Restrictive Lung Disease
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VC, FRC, TLC < 80%
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FEV1/FVC = Normal
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Pseudorestriction
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NMDz
Obesity
FLOW-VOLUME CURVE
in respiratory patients
• Restrictive disease
–  expansion of
the lung
– e.g., interstitial
fibrosis
• Obstructive disease
 FEV1
 FVC
–  resistance to
airflow
– e.g., COPD,
asthma
Summary
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Spirometry is used to diagnose and manage patients
with:
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COPD
ASTHMA
OCCUPATIONAL LUNG disease
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Knowledge of lung function helps in smoking cessation
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Spirometry i.e. lung function is an assessment of global
health