Obstructive lung disease

Obstructive Lung DiseaseAsthma and COPD

Kristopher R. Maday, MS, PA-C, CNSCAssistant Professor, Academic Coordinator

University of Alabama at BirminghamSurgical Physician Assistant Program

Greek: noisy breathing, panting

Asthma

Asthma

Very common diseaseAffects approximately 7-10% of the populationMore common in male children and female adults

(+) genetic predispositionPrevalence, hospitalizations, and fatal asthma exacerbations have all increased in the past 20 years

500,000 hospitalizations each year4500 deaths each year

Highest among African Americans ages 15-24

http://www.aaaai.org/about-the-aaaai/newsroom/asthma-statistics.aspx

AsthmaPathophysiology

Inflammatory cell infiltration with eosinophils, neutrophils, and T-lymphocytesMast cell activation leading to histamine releaseMicrovascular leakage and airway edemaGoblet cell hyperplasia with excessive mucous secretionCollagen deposition under basement membraneHypertrophy of bronchial smooth muscleDenudation of airway epithelium

Murphy DM, O’Byrne PM. Recent Advances in Pathophysiology of Asthma. CHEST. 2010;137(6):1417-1426.

Asthma

Risk FactorsAtopy

Hypersensitivity to IgE releaseObesity

PrecipitantsInhaled allergens

House dust mites, cockroaches, cat dander, seasonal pollensExerciseUpper respiratory tract infectionTobacco smokeOccupational exposuresGERD National Asthma Education and Prevention Program: Expert

Panel Report III (EPR-3) - 2007

Differential Diagnosis of Asthma

Upper Airway DisordersVocal cord paralysis, vocal cord dysfunction, foreign body aspiration, laryngotracheal masses, tracheal narrowing, tracheomalacia, airway edema

Lower Airway DisordersNon-asthmatic COPD, bronchiectasis, cystic fibrosis, bronchopulmonary dysplasia

Systemic VasculitidesChurge-Strauss, Wegeners granulomatosis

PsychiatricConversion disorders, emotional laryngeal wheezing

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

Asthma

Focused history is paramountPhysical exam is relatively insensitiveMost patients report episodic wheezing, dyspnea, chest tightness, productive cough at some pointFrequency of these symptoms are highly variableHistory of rashesHistory of allergies

Asthma

Physical ExamNormal during non-exacerbations Coughing paroxysm induced by deep inhalation or forced expiration

Suggests hyperreactivityNasal mucosal swellingIncreased nasal secretionsNasal polyps

AsthmaPhysical Exam during exacerbation

Tachypnea and tachycardia are ubiquitous25% may have RR > 30 and HR > 130

Diffuse musical wheezesBegins when peak flow decreased by 25%Presence and intensity does not reliably predict severityGreater airway obstruction with:

Wheezing during both inspiration and expirationAudible without stethoscopeHigh pitchedWheezing is absent

Prolonged expiratory phaseChest hyperinflationAccessory 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.

AsthmaGas Exchange Abnormalities

Virtually all asthmatics have hypoxemia during attacks

V/Q mismatchRespiratory 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.

AsthmaPulmonary Function Testing

2 reasons for testingAssess severityAssess reversibility

SpirometryMeasured before and 20 minutes after bronchodilatorMeasurements

Forced Expiratory Volume in 1 second (FEV1)Increase by 12% and 200mL

Forced Vital Capacity (FVC)Increase by 15% and 200mL

Peak Expiratory FlowDiurnal variation > 20% supports asthma diagnosis

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

Bronchoprovocation Challenge TestUsed in patients with suspected lung pathology but normal spirometry measures in the office2 types

Methacholine challengeExercise 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 baselineWilken 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.

Bronchoprovocation Challenge Test

MethacholineStart with nebulized saline solution

Established baselineIncreasing 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 spirometryCan use treadmill or cycle ergometerIncreasing intensity of activity until 80-90% of maximum heart rate

Generally takes 6-10 minutesOnce 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.

Asthma Management

4 components to diagnosis and managementAssessing and monitoring asthma severityPatient education designed to foster a partnership for care

Home monitoringControl of environmental factors and comorbid conditionsPharmacologic management

Prevention medicationsTreatment medications



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

Patient Education

Asthma Treatment

Goals of Asthma TherapyMinimize chronic symptoms that interfere with normal activityPrevent recurrent exacerbationsReduce or eliminate need for emergency department visitsMaintain normal or near-normal lung function


Asthma Treatment – Quick Relief

Inhaled Short Acting β-agonistsCan be MDI or nebulizerAlbuterol, Levalbuterol q4-6hrs

AnticholinergicsCan be MDI or nebulizerIpratropium q6hrs

Systemic CorticosteroidsCan PO, IM, or IV“Burst” course

0.5-1mg/kg/d in daily or BID dosing x 3-10 daysMethylprednisolone, Prednisolone, Prednisone


Krishnan JA, et al. An Umbrella Review: Corticosteroid Therapy for Adults with Acute Asthma. Am J Med. 2009;122:977-991.

Asthma Treatment – Long Term

Anti-Inflammatory AgentsInhaled corticosteroids (ICS) preferred

Beclomethasone, Budesonide, Flunisolide, Fluticasone, MometasoneBID or daily dosingSide effects

Hoarseness, dysphonia, cough, oral candidiasis


Asthma Treatment – Long TermBronchodilators

Long Acting β-agonistSalmeterol, Formoterol BID dosingNever used as monotherapy

Often combined in MDI with ICS

AnticholinergicTiotropiumSimilar response to LABA

Phosphodiesterase Inhibitor

TheophyllineNarrow therapeutic window

Mediator ModulatorsMast Cell Stabilizer

Cromolyn, NedocromilLeukotriene Modifier

Montelukast, Zafirlukast, Zileuton

ImmunomodulatorBinds free IgESQ injection q2-4 weeksOmalizumab



Acute Asthma Exacerbation

Determine severitySupplemental oxygen for:

SaO2 > 90%PaO2 > 60 mmHg

High dose delivery (nebulizer) of:Inhaled short acting -agonist (albuterol)

3 doses in 1 hour or continuous 1 hour treatmentAnticholinergic (ipratropium)

Systemic corticosteroids0.5-1mg/kg IM or IV

Magnesium Sulfate1-2g 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%

Referral to Pulmonologist

Patient not meeting goals after 6 months of treatmentStep 4 or higher> 2 courses of oral corticosteroids in last 12 monthsAny life-threatening exacerbation or exacerbation requiring hospitalization in last 12 monthsSuboptimal response to therapyComplicating comorbid conditions

Tobacco use, multiple environmental allergiesAtypical presentation or uncertain diagnosis

Greek: to smoke

COPD

Chronic Obstructive Pulmonary Disease

DefinitionProgressive airflow obstruction with airway hyperreactivity that is no longer fully reversible

EpidemiologyGreater than 16 million Americans have COPD

As many afflicted but not diagnosed 3rd leading of death in US672,000 hospital admissions per year16 million office visits to physicians per year$29.5 billion / year in direct health care costs yearly ̴120,000 deaths yearlyDeath 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 FactorsSmoking – 80% of casesOccupational exposuresEnvironmental PollutionHost 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 SymptomsTypically present in 5th and 6th decade

Though symptoms have been present for up to 10 years prior

DyspneaCoughSputum production


DiagnosisSpirometry

Post-bronchodilator:FEV1 < 80% predictedFEV1/FVC ratio < 0.7

Increased lung volumes as evidenced by:Increased RVIncreased TLCIncreased RV/TLC ratio

Arterial Blood GasNormal in early disease, but will eventually progress to chronic hypoxemia and a compensated respiratory acidosisOnly need to check if:

Concern for hypoxemia or hypercarbiaFEV1 < 40%Clinical signs of RHF or pulmonary HTN



Classification of COPD SeverityStage 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)


ImagingGenerally non-diagnostic


TreatmentStop smokingStop smokingStop smokingSupplemental OxygenMedicationsPulmonary RehabilitationSurgery


Smoking CessationSingle most effective intervention to reduce the risk of developing COPD and to stop its progressionAnnual 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 TherapyOnly drug therapy that improves the natural history of COPD

Increased survivalAfter 36 months:

Continuous – 65% survivalNocturnal – 45% survival

Reduced hospitalizationBetter quality of life

Medicare RequirementsPaO2 < 55 mmHg or SaO2 < 88% at rest on room airPaO2 56-59 mmHg or SaO2 89% if evidence of:

Dependent edemaPulmonary HTNHCT > 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.

MedicationsShort-Acting Inhaled Therapy

Do not alter decline in lung functionAlbuterol - less expensive, faster actingIpratropium – preferred first line

Longer duration and lack of sympathomimetic effectsLong Acting Inhaled Therapy

Formoterol, SalmetrolMaximal effect = Ipratropium but more expensive

TiotropiumDecreased exacerbations and hospitalizationsImproved dyspnea



MedicationsInhaled Corticosteroids

Not first line therapySynergistic effect with LABA

Decreased frequency of exacerbationsImproved functional status and quality of lifeNo long term improvement of FEV1 or mortality

Theophylline4th line agent without adequate control on anticholinergic, LABA, and ICSImproves dyspnea, exercise performance, and PFTNarrow therapeutic index



Pulmonary RehabilitationMultidisciplinary program that attempts to return patient to highest function capacity as possibleGraded aerobic activity designed to:

Improved exercise capacityDecrease hospitalizationsEnhance 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.

SurgeryLung Transplantation

2 year survival – 75%Requirements:

Severe lung disease, limited ADLs, exhaustion of medical therapy, adequate other organ function

Lung Volume Reduction SurgeryBenefits only a select populationBilateral resection of 20-30% of TLVImproves 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.


Acute COPD Exacerbation

Often a prodrome of symptoms up to 7 days before the acute exacerbation

Leads to a sub-acute decrease in lung functionCauses

Respiratory infectionMost frequent causeViral

More severe symptoms and longer durationBacterial

S.pneumoniae, H.influenza, M.catarrhalisP.aeruginosa more prevalent in advanced stages


Acute COPD ExacerbationTreatment

AdmissionSevere symptoms, co-morbidities, advanced disease

Supplemental oxygenPaO2 > 60 mmHg or SaO2 > 90%

Inhaled MedicationsAlbuterol and Ipratropium q6hr

AntibioticsDepends on local biotagramNeeds to cover MRSA, S.pneumoniae, and P.aeruginosaDuration of therapy 3-7 days

CorticosteroidsIV 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.

Referral to Pulmonologist

Severe (Stage III or IV) or rapidly progressing diseaseCOPD before age 402 or more exacerbation per year despite optimal therapySymptoms out of proportion to airway obstruction severityNeed for long-term oxygen therapyComorbid conditions

CHF, lung cancer, CAD

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Obstructive lung disease

Health & Medicine