COPD

Question 1

Definition

Answer 1

-A common preventable and treatable disease
-characterized by persistent airflow limitation
-usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases.
-The fourth leading cause of death
-Affects more than 10M persons in the U.S.
-Problem with breathing out
Reduced FEV1/ FVC %

Question 2

Caused by:

Answer 2

Chronic airflow limitation is caused by;

• A mixture of small airways disease (obstructive bronchiolitis)
• Parenchymal destruction (emphysema)
• Emphysema – Destruction of the gas exchanging surfaces of the lung (alveoli)
• Chronic bronchitis – the presence of cough and sputum production for at least 3 months in each of two consecutive years.

Question 3

Risk factors

Answer 3

• Cigarette smoking - Major risk factor for mortality from chronic bronchitis and emphysema.
• Cigarette smoking - Major risk factor for mortality from chronic bronchitis and emphysema.
• General exposure to dust (Coal mining, gold mining, and cotton textile dust) and fumes at work.

Question 4

Airway changes

Answer 4

-“air trapping” ( increased residual volume and increased ratio of residual volume to total lung capacity)
-Progressive hyperinflation causes flat diaphragm
-decreased zone of opposition between the diaphragm and abdominal wall
-muscle fibers of flattened diaphragm are shorter
-Distended thoracic cage
Large airways;
-Goblet cell increase in number and in extent
-Bronchi undergo squamous metaplasia
-Smooth muscle hypertrophy and bronchial hyperactivity
-Neutrophil influx
Small airways:
-Goblet cell metaplasia replacing surfactant – secreting clara cells.
-Infiltrations of mononuclear phagocytes
-Smooth muscle cell hypertrophy
-Luminal narrowing by fibrosis
-Excess mucus, edema, and cellular infiltration
-Reduced surfactant
-Respiratory bronchiolitis with mononuclear inflammatory cells
-Loss of bronchiolar attachment

Major site of increased resistance in most individuals with COPD is in airways < 2mm

Question 5

Emphysema

Answer 5

• is characterized by destruction of gas- exchanging air spaces,
• respiratory bronchioles, alveolar ducts, alveoli
• Wall perforation and obliteration
• bronchoalveolar lavage fluid of smokers
• Centriacinar- most frequently associated with cigarette smoking; Enlarged air space, Usually most prominent in the upper lobes and superior segments of lower lobes
• Panacinar – abnormally large spaces evenly distributed within and across acinar units.Usually observed in patients with α1 AT deficiency. Often predilection for the lower lobes.

Question 6

History/Signs and Symptoms

Answer 6

• Most common symptoms: cough, sputum production, and exertional dyspnea
• Associated with acute illness or exacerbation
• Development of exertional dyspnea is insidious
• Advanced COPD:- worsening dyspnea on exertion
• Most advanced:- breathlessness while doing simple activities
• Early stages: entirely normal physical examination.
• More severe disease – prolonged expiratory phase and may include expiratory wheezing
• Hyperinflation – barrel chest and enlarged lung volumes with poor diaphragmatic excursion.
• Cyanosis in the lips and nail beds
• Systemic wasting, with significant weight loss, bitemporal wasting, and diffuse loss of subcutaneous adipose tissue.

Question 7

Lab findings

Answer 7

• Pulmonary function test – airflow obstruction with a reduction in FEV1 and FEV1/FVC
• Worsening disease severity – lung volumes may increase (TLC, FRC, and RV)
• Diffusing capacity may be reduced
• ABG and oximetry may demonstrate resting or exertional hypoxemia.
• α1-AT deficiency test

Question 8

Tx

Answer 8

Stable phase COPD
-smoking cessation
-O2 therapy in chronically hypoxemic patients
-lung volume reduction surgery
Pharmacotherapy
-Smoking cessation
-Bupropion- originally developed as an antidepressant
-Nicotine replacement therapy available as gum
-Transdermal patch
-Bronchodilators, Anticholinergic, Tiotropium 
ß-agonists-
-salmeterol over ipratropium bromide
-inhaled glucocoricoids-
-oral glucocorticoids
-Theophylline
-Oxygen

• Pulmonary rehabilitation
• Lung volume reduction surgery
• Lung transplantation:

Acute exacerbation

• Bronchodilators
• Antibiotics
• Glucocorticoids
• Oxygen
• Mechanical ventilator support