Obstructive lung disease

Kristopher R. Maday, MS, PA-C, CNSC
Assistant Professor, Academic Coordinator
University of Alabama at Birmingham
Surgical Physician Assistant Program

Greek: noisy breathing, panting

Very common disease
Affects approximately 7-10% of the population
More common in male children and female adults
(+) genetic predisposition
Prevalence, hospitalizations, and fatal asthma
exacerbations have all increased in the past 20
years
500,000 hospitalizations each year
4500 deaths each year
Highest among African Americans ages 15-24
http://www.aaaai.org/about-the-aaaai/newsroom/asthma-statistics.aspx

Pathophysiology
Inflammatory cell infiltration
with eosinophils, neutrophils,
and T-lymphocytes
Mast cell activation leading to
histamine release
Microvascular leakage and
airway edema
Goblet cell hyperplasia with
excessive mucous secretion
Collagen deposition under
basement membrane
Hypertrophy of bronchial
smooth muscle
Denudation of airway
epithelium
Murphy DM, O’Byrne PM. Recent Advances in Pathophysiology of Asthma.
CHEST. 2010;137(6):1417-1426.

Risk Factors
Atopy
Hypersensitivity to IgE release
Obesity
Precipitants
Inhaled allergens
House dust mites, cockroaches, cat dander, seasonal pollens
Exercise
Upper respiratory tract infection
Tobacco smoke
Occupational exposures
GERD
National Asthma Education and Prevention Program: Expert
Panel Report III (EPR-3) - 2007

Upper Airway Disorders
Vocal cord paralysis, vocal cord dysfunction, foreign
body aspiration, laryngotracheal masses, tracheal
narrowing, tracheomalacia, airway edema
Lower Airway Disorders
Non-asthmatic COPD, bronchiectasis, cystic fibrosis,
bronchopulmonary dysplasia
Systemic Vasculitides
Churge-Strauss, Wegeners granulomatosis
Psychiatric
Conversion disorders, emotional laryngeal wheezing
GERD National Asthma Education and Prevention Program: Expert

Focused history is paramount
Physical exam is relatively insensitive
Most patients report episodic wheezing, dyspnea,
chest tightness, productive cough at some point
Frequency of these symptoms are highly variable
History of rashes
History of allergies

Physical Exam
Normal during non-exacerbations
Coughing paroxysm induced by deep inhalation or
forced expiration
Suggests hyperreactivity
Nasal mucosal swelling
Increased nasal secretions
Nasal polyps

Physical Exam during exacerbation
Tachypnea and tachycardia are ubiquitous
25% may have RR > 30 and HR > 130
Diffuse musical wheezes
Begins when peak flow decreased by 25%
Presence and intensity does not reliably predict severity
Greater airway obstruction with:
Wheezing during both inspiration and expiration
Audible without stethoscope
High pitched
Wheezing is absent
Prolonged expiratory phase
Chest hyperinflation
Accessory muscle use or retractions
Mannam P, Siegel MD. Analytic Review: Management of
Life-Threatening Asthma in Adults. J Intensive Care Med.
2010;25(1):3-15.

Gas Exchange
Abnormalities
Virtually all asthmatics
have hypoxemia during
attacks
V/Q mismatch
Respiratory alkalosis
occurs in 75% of acute
asthma attacks
PaCO2 will normalize as
attack worsens
Rodriguez-Roisin R. Acute Severe Asthma: Pathophysiology and Pathobiology of
Gas Exhange Abnormalities. Eur Respir J. 1997;10:1359-1371.

Pulmonary Function Testing
2 reasons for testing
Assess severity
Assess reversibility
Spirometry
Measured before and 20 minutes after bronchodilator
Measurements
Forced Expiratory Volume in 1 second (FEV1)
Increase by 12% and 200mL
Forced Vital Capacity (FVC)
Increase by 15% and 200mL
Peak Expiratory Flow
Diurnal variation > 20% supports asthma diagnosis

Used in patients with suspected lung pathology but
normal spirometry measures in the office
2 types
Methacholine challenge
Exercise challenge
Exclusion criteria
• Absolute contraindications
• Severe airflow limitation (FEV1 < 1.0 L or 60% predicted)
• Heart attack or stroke within past 3 months
• Uncontrolled HTN (SBP > 200 or DBP > 100)
• Aortic aneurysm
• Relative contraindications
• Moderate airflow limitation (FEV1 < 1.5 L or 75% predicted)
• Pregnancy or breastfeeding
• Inability to achieve spirometry results of acceptable quality
Positive test is a reduction of FEV1 > 20% of baseline
Wilken LA, Joo MJ. Pulmonary Function and Related Tests. In:
Basic Skills in Interpreting Laboratory Data, Lee M, 4th ed. Bethesda,
MD: American Society of Health System Pharmacists; 2009:191-206.

Methacholine
Start with nebulized saline
solution
Established baseline
Increasing concentration of
methacholine is inhaled (every
5 minutes)
Spirometry is performed after
each concentration increase
Recorded as PC20FEV1 (mg/mL)
Positive test < 8mg/mL
Exercise
Baseline spirometry
Can use treadmill or cycle
ergometer
Increasing intensity of activity
until 80-90% of maximum heart
rate
Generally takes 6-10 minutes
Once completed, serial
spirometry is performed every
5 minutes for 30 minutes
Wilken LA, Joo MJ. Pulmonary Function and Related Tests. In:
Basic Skills in Interpreting Laboratory Data, Lee M, 4th ed. Bethesda,
MD: American Society of Health System Pharmacists; 2009:191-206.

4 components to diagnosis and management
Assessing and monitoring asthma severity
Patient education designed to foster a partnership
for care
Home monitoring
Control of environmental factors and comorbid
conditions
Pharmacologic management
Prevention medications
Treatment medications

National Asthma Education and Prevention Program: Expert Panel Report III (EPR-3) - 2007

Chesnutt MS, Pendergast TJ, Tavan ET. Pulmonary Disorders. In: Current Medical Diagnosis and Treatment 2013, Papadakis
MA. 52nd ed. New York. McGraw-Hill. 2013;242-323. Adapted from National Asthma Education and Prevention Program:
Expert Panel Report III (EPR-3) - 2007

Goals of Asthma Therapy
Minimize chronic symptoms that interfere with
normal activity
Prevent recurrent exacerbations
Reduce or eliminate need for emergency
department visits
Maintain normal or near-normal lung function
National Asthma Education and Prevention Program:

Inhaled Short Acting β-agonists
Can be MDI or nebulizer
Albuterol, Levalbuterol q4-6hrs
Anticholinergics
Can be MDI or nebulizer
Ipratropium q6hrs
Systemic Corticosteroids
Can PO, IM, or IV
“Burst” course
0.5-1mg/kg/d in daily or BID dosing x 3-10 days
Methylprednisolone, Prednisolone, Prednisone
Krishnan JA, et al. An Umbrella Review: Corticosteroid Therapy for
Adults with Acute Asthma. Am J Med. 2009;122:977-991.

Anti-Inflammatory Agents
Inhaled corticosteroids (ICS) preferred
Beclomethasone, Budesonide, Flunisolide, Fluticasone,
Mometasone
BID or daily dosing
Side effects
Hoarseness, dysphonia, cough, oral candidiasis

Bronchodilators
Long Acting β-agonist
Salmeterol, Formoterol
BID dosing
Never used as monotherapy
Often combined in MDI with
ICS
Anticholinergic
Tiotropium
Similar response to LABA
Phosphodiesterase
Inhibitor
Theophylline
Narrow therapeutic window
Mediator Modulators
Mast Cell Stabilizer
Cromolyn, Nedocromil
Leukotriene Modifier
Montelukast, Zafirlukast,
Zileuton
Immunomodulator
Binds free IgE
SQ injection q2-4 weeks
Omalizumab

Determine severity
Supplemental oxygen for:
SaO2 > 90%
PaO2 > 60 mmHg
High dose delivery (nebulizer) of:
Inhaled short acting β-agonist (albuterol)
3 doses in 1 hour or continuous 1 hour treatment
Anticholinergic (ipratropium)
Systemic corticosteroids
0.5-1mg/kg IM or IV
Magnesium Sulfate
1-2g IV over 30 minutes
Lazarus SC. Emergency Treatment of Asthma. N
Engl J Med. 2010;363:755-764.

Evaluation of Asthma Exacerbation Severity (EPR-3 - 2007)
Mild Moderate Severe Imminent
Respiratory Arrest
Symptoms
Breathlessness With exertion At rest At rest
Talks in: Sentences Phrases Words
Alertness Anxious Agitated Agitated Drowsy, Confused
Signs
Respiratory Rate 20-25 25-30 > 30
Accessory muscle use Usually not Commonly Usually Parodoxical
thoracoabdominal
movement
Wheeze End expiratory Throughout expiration Inspiratory and expiratory Absence
Heart Rate < 100 100-120 > 120 < 60
Functional Assessment
Peak Expiratory Flow > 70% 40-69% < 40% < 25%
PaO2 80-100 mmHg 60-80 mmHg < 60 mmHg
PaCO2 < 40 mmHg 40-50 mmHg > 50 mmHg
SaO2 > 95% 90-95% < 90%

Patient not meeting goals after 6 months of
treatment
Step 4 or higher
> 2 courses of oral corticosteroids in last 12
months
Any life-threatening exacerbation or
exacerbation requiring hospitalization in last 12
months
Suboptimal response to therapy
Complicating comorbid conditions
Tobacco use, multiple environmental allergies
Atypical presentation or uncertain diagnosis

Definition
Progressive airflow obstruction with airway
hyperreactivity that is no longer fully reversible
Epidemiology
Greater than 16 million Americans have COPD
As many afflicted but not diagnosed
3rd leading of death in US
672,000 hospital admissions per year
16 million office visits to physicians per year
$29.5 billion / year in direct health care costs yearly
̴120,000 deaths yearly
Death rate from COPD increasing past several decades,
especially among women http://www.lung.org/lung-disease/copd/resources/facts-
figures/COPD-Fact-Sheet.html

Emphysema
Abnormal permanent
enlargement of air spaces
distal to terminal
bronchioles
Destruction of lung matrix
Loss of elastic recoil
Chronic Bronchitis
Excessive secretion of
mucus with daily
productive cough for 3
months or more in at
least 2 consecutive
years
Peribronchiol fibrosis
Airway narrowing

Chesnutt MS, Pendergast TJ, Tavan ET. Pulmonary Disorders. In: Current
Medical Diagnosis and Treatment 2013, Papadakis MA. 52nd ed. New York.
McGraw-Hill. 2013;242-323

Risk Factors
Smoking – 80% of cases
Occupational exposures
Environmental Pollution
Host factors
Rabe KF, et al. Global Strategy for Diagnosis, Management, and
Prevention of Chronic Obstructive Pulmonary Disease: GOLD Executive
Summary. AM J Respir Crit Care Med. 2007;176:532-555.

Signs and Symptoms
Typically present in 5th and 6th decade
Though symptoms have been present for up to 10 years
prior
Dyspnea
Cough
Sputum production

Diagnosis
Spirometry
Post-bronchodilator:
FEV1 < 80% predicted
FEV1/FVC ratio < 0.7
Increased lung volumes as evidenced by:
Increased RV
Increased TLC
Increased RV/TLC ratio
Arterial Blood Gas
Normal in early disease, but will eventually progress to chronic
hypoxemia and a compensated respiratory acidosis
Only need to check if:
Concern for hypoxemia or hypercarbia
FEV1 < 40%
Clinical signs of RHF or pulmonary HTN

Stage Description Characteristics
I Mild FEV1 > 80%
II Moderate FEV1 50-80%
III Severe FEV1 30-50%
IV Very Severe FEV1 < 30% *
*Chronic respiratory failure or right heart failure with FEV1< 50%
*Chronic respiratory failure is defined as a PaO2 < 60mmHg or PaCO2 > 55mmHg while breathing
room air at sea level
All have FEV1/FVC ratio less than 70% (Hallmark of obstructive diseases)

Imaging
Generally non-diagnostic

Treatment
Stop smoking
Stop smoking
Stop smoking
Supplemental Oxygen
Medications
Pulmonary Rehabilitation
Surgery

Smoking Cessation
Single most effective intervention to reduce the risk
of developing COPD and to stop its progression
Annual rate of decline in FEV1 over 4 years for
quitters was half that for continuing smokers
Scanlon PD, et al. Smoking Cessation and Lung
Function in Mild-to-Moderate Chronic Obstructive
Pulmonary Disease: The Lung Health Study. Am J
Respir Crit Care Med. 2000;161:381-390.

Home Oxygen Therapy
Only drug therapy that improves the natural history of
COPD
Increased survival
After 36 months:
Continuous – 65% survival
Nocturnal – 45% survival
Reduced hospitalization
Better quality of life
Medicare Requirements
PaO2 < 55 mmHg or SaO2 < 88% at rest on room air
PaO2 56-59 mmHg or SaO2 89% if evidence of:
Dependent edema
Pulmonary HTN
HCT > 56% Centers for Medicare and Medicaid Services. National Coverage
Determination for Home Use of Oxygen. 1993. 100-3;240.2.
Stoller JK, et al. Oxygen Therapy for Patients with COPD: Current
Evidence and the Long-Term Oxygen Treatment Trial. CHEST.
2010;138(1):179-187.

Medications
Short-Acting Inhaled Therapy
Do not alter decline in lung function
Albuterol - less expensive, faster acting
Ipratropium – preferred first line
Longer duration and lack of sympathomimetic effects
Long Acting Inhaled Therapy
Formoterol, Salmetrol
Maximal effect = Ipratropium but more expensive
Tiotropium
Decreased exacerbations and hospitalizations
Improved dyspnea

Medications
Inhaled Corticosteroids
Not first line therapy
Synergistic effect with LABA
Decreased frequency of exacerbations
Improved functional status and quality of life
No long term improvement of FEV1 or mortality
Theophylline
4th line agent without adequate control on
anticholinergic, LABA, and ICS
Improves dyspnea, exercise performance, and PFT
Narrow therapeutic index

Pulmonary Rehabilitation
Multidisciplinary program that attempts to return
patient to highest function capacity as possible
Graded aerobic activity designed to:
Improved exercise capacity
Decrease hospitalizations
Enhance quality of life
Foglio K, Bianchi L, Bruletti G, Battista L, Pagani M, Ambrosino N.
Long-term effectiveness of pulmonary rehabilitation in patients
with chronic airway obstruction. Eur Respir J 1999;13:125–132.

Surgery
Lung Transplantation
2 year survival – 75%
Requirements:
Severe lung disease, limited ADLs, exhaustion of
medical therapy, adequate other organ function
Lung Volume Reduction Surgery
Benefits only a select population
Bilateral resection of 20-30% of TLV
Improves functional capacity and exercise tolerance, but
no change in mortality when compared to medical
therapy only
Martinez FJ, Change A. Surgical Therapy for Chronic Obstructive
Pulmonary Disease. Semin Respir Crit Care Med. 2005;25(2):167-191.

Often a prodrome of symptoms up to 7 days
before the acute exacerbation
Leads to a sub-acute decrease in lung function
Causes
Respiratory infection
Most frequent cause
Viral
More severe symptoms and longer duration
Bacterial
S.pneumoniae, H.influenza, M.catarrhalis
P.aeruginosa more prevalent in advanced stages

Treatment
Admission
Severe symptoms, co-morbidities, advanced disease
Supplemental oxygen
PaO2 > 60 mmHg or SaO2 > 90%
Inhaled Medications
Albuterol and Ipratropium q6hr
Antibiotics
Depends on local biotagram
Needs to cover MRSA, S.pneumoniae, and P.aeruginosa
Duration of therapy 3-7 days
Corticosteroids
IV Solumedrol 125mg BID
Noninvasive Positive Pressure Ventilation for hypercapnic
respiratory failure
Daniels JM, et al. Antibiotics in Addition to Systemic
Corticosteroids for Acute Exacerbations of Chronic Obstructive
Pulmonary Disease. Am J Respir Crit Care Med.
2010;181:150-157.

Severe (Stage III or IV) or rapidly progressing
disease
COPD before age 40
2 or more exacerbation per year despite optimal
therapy
Symptoms out of proportion to airway
obstruction severity
Need for long-term oxygen therapy
Comorbid conditions
CHF, lung cancer, CAD

Obstructive lung disease

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