Chronic Obstructive Pulmonary Disease (COPD)

Definitions
Chronic obstructive pulmonary disease (COPD) encompasses several diffuse pulmonary diseases, including chronic bronchitis, asthma, cystic fibrosis, bronchiectasis, and emphysema:The result is irreversible airflow obstruction.



Classification

Chronic bronchitis	increased mucus production and recurrent cough present on most days for at least 3 months during at least 2 consecutive years. Known as blue bloater.
Emphysema	destruction of interalveolar wall; it occurs in the distal or terminal airways and involves both airways and lung parenchyma. Known as pink puffer.

Epidemiology
Affects ~10–20% of adults; >100,000 deaths/year in US
14 million people have chronic bronchitis; 2 million people have emphysema.
4th leading cause of death in US

Aetiology
Smoking- Cigarettes,Pipes, cigars – lower rates than cigarette smokers but higher than non-smokers
Passive smoking, especially adults whose parents smoked
Severe viral pneumonia early in life
Aging
Alcohol consumption
Airway hyperactivity
Alpha1-antitrypsin deficiency

Pathophysiology
Impaired gas (CO2 and O2) exchange
Airway obstruction by mucus in chronic bronchitis
The increased number of activated polymorphonuclear leukocytes and macrophages release elastases in a manner that cannot be counteracted effectively by antiproteases, resulting in lung destruction.
Destruction of lung parenchyma in emphysema

Presentation

Chronic bronchitis	Cough, sputum production, frequent infections, intermittent dyspnea, wheeze, hemoptysis, morning headache, pedal edema Cyanosis, wheezing, weight gain, diminished breath sounds, distant heart sounds
Emphysema	Cough, sputum production, frequent infections, intermittent dyspnea, wheeze, hemoptysis, morning headache, pedal edema Barrel chest, minimal wheezing, accessory muscles used, pursed lip breathing, cyanosis slight or absent, breath sounds diminished

Ddx
Asthma
Bronchiectasis
Lung cancer
Acute viral infection
Normal aging of lungs
Occupational asthma
Chronic pulmonary embolism
Sleep apnea
Primary alveolar hypoventilation
Chronic sinusitis

Investigation

FBC	Increased hemoglobin/hematocrit secondary to haemoconcentration
Pulmonary Function test (PFT)	Not indicated during acute exacerbation Decreased FEV1 and resulting reduction in FEV1/FVC (forced vital capacity) ratio Poor or absent reversibility to bronchodilator Normal or reduced FVC. Normal or increased total lung capacity Increased residual volume and functional residual capacity (FRC) Diffusing capacity is normal or reduced. Chronic obstructive pulmonary disease (COPD). Pressure volume curve comparing lungs with emphysema lungs and restrictive lungs to normal lungs.
ABG	Obtain in patients with FEV1 < 40% predicted Clinical signs of respiratory or right heart failure (Central cyanosis, ankle swelling, increase in JVP) Respiratory Failure:(PaO2 < 60 mm Hg with or without PaCO2 > 45 mm Hg while breathing air at sea level
Six-minute walking distance	The distance walked in 6 minutes is a good predictor of all-cause and respiratory mortality in patients with moderate COPD. used as a part of the multidimensional BODE index (body mass index, obstruction [FEV1], dyspnea [ie, Medical Research Council Dyspnea Scale], and exercise capacity
Sputum	The pathogens most frequently cultured during exacerbations are Streptococcus pneumoniae and Haemophilus influenzae. Moraxella catarrhalis is also a common organism, and Pseudomonas aeruginosa can be seen in patients with severe obstruction.
CXR	* signs of hyperinflation, including a flattening of the diaphragm, increased retrosternal air space, and a long narrow heart shadow. Rapid-tapering vascular shadows accompanied by hyperlucency of the lungs are signs of emphysema. With complicating pulmonary hypertension, the hilar vascular shadows are prominent, with possible right ventricular enlargement and opacity in the lower retrosternal air space.
High-resolution CT	highly specific for diagnosing emphysema may provide an adjunct to diagnosing various forms of COPD may help determine if surgical intervention Chronic obstructive pulmonary disease (COPD). A CT scan shows hyperlucency due to hypovascularity and bullae formation diffusely, predominantly in upper lobes.
Alpha-1 antitrypsin	Consider in patients with COPD < age 45 Strong family hx of early COPD or with alpha-1antitrypsin deficiency

GOLD Criteria
Spirometry can help to determine the severity of COPD. The FEV1 (measured after bronchodilator medication) In all stages of COPD, FEV1/FVC <0.7

Severity of COPD	FEV1 % predicted
Mild	≥80
Moderate	50–79
Severe	30–49
Very severe	<30 or chronic respiratory failure symptoms

Management
(1) Assess and Monitor Disease;
(2) Reduce Risk Factors;
(3) Manage Stable COPD; and
(4) Manage Exacerbations.

(1) Assess and Monitor Disease

Initial Visit	Pattern of symptom development Exposure to risk factors History of exacerbations or previous hospitalizations for respiratory disorder Past medical history Family history Social history Impact of disease on patient’s life Effect on family routines Feelings of depression or anxiety Social and family support available to the patient Possibilities for reducing risk factors, especially smoking cessation
Testing	Spirometry, ABG, Alpha-1 antitrypsin
Follow-up	Discuss new or worsening symptoms, spirometry, ABG Monitor pharmacotherapy: Dosages, Adherence, Inhaler technique, Effectiveness of current regimen at controlling symptoms, Side effects of treatment Monitor co-morbid conditions:Bronchial carcinoma, Tuberculosis, Sleep apnea, Left heart failure

(2) Reduce Risk Factors

Smoking cessation	Offer tobacco dependence treatment at every visit. Three types of counseling Practical counseling Social support as part of the treatment Social support arranged outside of the treatment least one medication should be added to counseling if necessary Nicotine gum, inhaler, nasal spray, trasndermal patch, sublingual tablet, lozenges Bupropion nortriptyline Strategy: Ask, Advise, Assess, Assist, Arrange
Occupational Exposure	Primary prevention- Eliminate or reduce exposures to various substances in the workplace Secondary prevention- Surveillance and early detection
Indoor/ outdoor air pollutants	Implement measures to reduce or avoid indoor air pollution from biomass fuel burned for cooking and heating in poorly ventilated dwellings Advise patients to monitor public announcements of air quality Avoid vigorous exercise outdoors or stay indoors during pollution episodes, depending on COPD severity

(3) Manage Stable COPD

Patient education	Smoking cessation Basic information about COPD and pathophysiology of the disease General approach to therapy and specific aspects of medical treatment Self-management skills Strategies to help minimize dyspnea Advice about when to seek help Self-management and decision-making in exacerbations Advance directives and end-of-life issues.
Treat based on Stage	Stage 0: At Risk Avoid risk factors Offer influenza vaccination Stage I: Mild COPD Above + Use short-acting bronchodilators as needed Stage II: Moderate COPD Above + Offer influenza vaccine Add regular treatment with1 or more long-acting bronchodilators Add rehabilitation Stage III: Severe COPD Above + Add inhaled glucocorticoids if repeated exacerbations Stage IV: Very Severe COPD Above + Add long-term oxygen if chronic respiratory failure Consider surgical treatments
Bronchodilators	Beta2-agonists Short-acting: albuterol Long-acting: salmeterol (Serevent™), formoterol (Foradil™) Anticholinergics Short acting: ipratropium bromide (Atrovent™) Long acting: tiotropium bromide (Spiriva™) Methylxanthines (Theophylline™) Combination bronchodilators Fenoterol/ipratropium (Duovent™) Salbutamol/ipratropium (Combivent™)
Glucocorticosteroids (inhaled)	Benefit Does not modify the long-term decline in FEV1 BUT does reduce the frequency of excacerbations and improves health status Reversibility testing Treatment trial of inhaled glucocorticosteroids for 6 to 12 weeks then repeat spirometry with and without bronchodilators Patients most likely to respond to inhaled steroids have an FEV1 increase of 200 mL and 15% above baseline post-bronchodilator Example Beclomethasone (Vanceril™) Budesonide (Pulmicort™) Fluticasone (Flovent™) Triamcinolone (Azmacort™)
Immunization	Influenza yearly Reduces serious illness and death in COPD patients by approximately 50% Give once yearly: autumn OR twice yearly: autumn and winter Pneumovax Sufficient data to support its general use in COPD is lacking, but it is commonly used
Other medications	Alpha-1 Antitrypsin Augmentation Therapy Only if this deficiency is present in an individual should they undergo treatment Antibiotics Prophylactic use is NOT recommended Can be used in the treatment of infectious exacerbations of COPD Mucolytic agents Overall benefits are small, so currently not recommended for widespread use Types: Ambroxol, Erdosteine (Erdostin, Mucotec) Carbocysteine (Mucodyne), Iodinated gylerol (Expigen)
Rehabilitation	Minimum effective length of time = 2 months Setting: inpatient OR outpatient OR home Baseline and outcome assessments of each participant should be made to quantifyindividual gains and target areas for improvement Measurement of spirometry before and after a bronchodilator drug Assessment of exercise capacity Assessment of inspiratory and expiratory muscle strength and lower limb strength
Oxygen therapy	Indications: PaO2 at or below 55 mm Hg or SaO2 at or below 88% with or without hypercapnia PaO2 between 55-60 mm Hg or SaO2 89% IF pulmonary hypertension, peripheral edema suggesting congestive heart failure, or polycythemia (Hct > 55%) Need to use at least 15 hours per day in patients with chronic respiratory failure to improve survival Can have a beneficial impact on hemodynamics, hematologic characteristics, exercise capacity, lung mechanics and mental state
Surgical	Bullectomy Effective in reducing dyspnea and improving lung function in appropriately selected patient Lung volume reduction surgery Parts of the lung are resected to reduce hyperinflation Does not improve life expectancy Does improve exercise capacity in patients with predominantly upper lobe emphysema and a low post-rehabilitation exercise capacity May improve global health status in patients with heterogeneous emphysema High hospital costs; still experimental/palliative Lung transplantation Improves quality of life and functional capacity in appropriately selected patient Criteria for referral:(All 4 must be present) FEV1 < 35% predicted PaO2 < 55-60 mm Hg PaCO2 > 50 mm Hg Secondary pulmonary hypertension Surgical risk in COPD Increased risk of post-operative pulmonary complications Risk of complications increases as the incision approaches the diaphragm Epidural and spinal anesthesia have a lower risk than general anesthesia Postpone surgery if the patient has a COPD exacerbation

(4) Manage Exacerbations.

Diagnosis and Assessment of Severity	History, PFT, ABG, CXR, ECG, Sputum, Assess for electrolyte disturbance
Oxygen therapy	Administer enough to maintain PaO2 > 60 mmHG or SaO2 > 90% Monitor patient closely for CO2 retention or acidosis
Bronchodilators (inhaled)	Increase doses or frequency Combine ß2 agonists and anticholinergics Use spacers or air-driven nebulizers Consider adding IV methylxanthine (aminophylline) if needed
Glucocorticosteroids (oral or IV)	Recommended as an addition to bronchodilator therapy If baseline FEV1 < 50% predicted 30-40 mg oral prednisolone x 10 days OR nebulized budesonide (Pulmicort™)
Antibiotics	IF breathlessness and cough are increased AND sputum is purulent and increased in volume
Chest percussion	Manual or mechanical chest percussion and postural drainage may be beneficial in patients producing > 25 mL sputum per day OR with lobar atelectasis.
Ventilatory Support	Decrease mortality and morbidity Relieve symptoms Used most commonly in Stage IV, Very Severe COPD Forms: NIPPV Non-invasive using negative or positive pressure devices Success rates of 80-85% Increases pH, reduces PaCO2, reduces severity of breathlessness in the first 4 hours of treatment Decreases length of hospital stay/ mortality/intubation rate types C-PAP, Bi-PAP Selection criteria Moderate to severe dyspnea with use of accessory muscles and paradoxical abdominal motion Moderate to severe acidosis (pH < 7.35) and hypercapnia (PaCO2 > 45 mmHg) Respiratory frequency > 25 breaths/minute Contraindication: Respiratory arrest Cardiovascular instability- Hypotension, Arrhythmias, MI Somnolence, impaired mental status, lack of cooperation High aspiration risk – viscous/copius secretions Recent facial or gastroesophageal surgery Cranio-facial trauma, fixed nasopharyngeal abnormalities Extreme obesity Invasive invasive/mechanical with oro- or naso-tracheal tube OR tracheostomy Indications: Severe dyspnea with use of accessory muscles and paradoxical abdominal motion Respiratory rate > 35 breaths/minute Life-threatening hypoxemia: PaO2 < 40 mm Hg Severe acidosis (pH < 7.25) and hypercapnia (PaCO2 > 60 mm Hg) Respiratory arrest Somnolence, impaired mental status Cardiovascular complications NIPPV failure Metabolic abnormalities/sepsis/pneumonia/pulmonary embolism/barotrauma/massive pleural effusion Weaning from ventilator: Methods still debated weaning is shorted as long as a protocol is used. NIPPV used during the weaning process has shortened weaning time, reduced stay in the ICU,decreased the incidence of nosocomial pneumonia, and improved 60-day survival rates
Discharge criteria	Not waking at night due to dyspnea Ability to ambulate Patient should have adequate gas exchange. Hypoxia can be treated with home O2 (may only be temporary) Inhaled β-agonist therapy no more frequently than q.4h.
Follow up	4-6 weeks after discharge Assess: Ability to cope in usual environment Inhaler technique Understanding of recommended treatment regimen Measure FEV1 Determine need for long-term oxygen therapy and/or home nebulizer (for patients with very severe COPD, Stage IV)

Complications

• Infection is common.
• Cor pulmonale
• Secondary polycythemia
• Bullous lung disease
• Acute or chronic respiratory failure
• Pulmonary HTN
• Malnutrition
• Pneumothorax
• Poor sleep quality
• Arrhythmias

Prognosis

• Patient's age and postbronchodilator FEV1 are the most important predictors of prognosis. Young age and FEV1 >50% predicted to have a good prognosis. Older patients do worse.
• Supplemental O2, when indicated, is shown to increase survival (may only need at night).
• Smoking cessation improves prognosis.
• Malnutrition, cor pulmonale, hypercapnia, and pulse >100 indicate a poor prognosis.