Questions on COPD

Definition and classification

  • What is COPD? A, hl
  • What are the components of COPD? Hl
  • Define chronic bronchitis. Hl
  • Define emphysema. Hl
  • Define airflow obstruction. hl
  • What are the stages or classification of COPD? A
  • What are the obstructive pulmonary diseases? H33
    • What are the restrictive pulmonary diseases? H34
    • How can you differentiate obstructive from restrictive lung diseases? H35
  • Define respiratory failure. Hl
    • What are the types of respiratory failure? hl

Epidemiology

  • How many smokers are susceptible to develop COPD? hl

Etiology and Pathophysiology

  • What are the mechanisms of airflow limitation in COPD? A
    • Is airflow obstruction reversible in COPD? hl
  • What are the risk factors or causes of COPD? A, hl
  • How much smoking accounts for COPD? hl
  • What organisms are associated with acute exacerbation of COPD? A, hl
  • What are the patterns of emphysema? Hl
  • What are the causes of type I respiratory failure? Hl
  • What are the causes of type II respiratory failure? hl

Clinical manifestations

  • What are the presentations of COPD? A
  • What are the common presentations of COPD? Hl
    • Tell the MRC grading of dyspnea. Hl
  • What are the extrapulmonary manifestations (systemic features) in COPD? A, hl
  • What are the causes of wheeze? H11

Examinations

  • What findings can you get by examining this patient? H50
  • How can you predict acute infective exacerbation? Hl

Investigations

  • What investigations should be done in COPD? A, hl
    • Tell the radiological findings in COPD. Hl
    • What may be the ECG findings in COPD? Hl
    • What may be the ABG abnormalities in COPD? hl
  • What are the findings in spirometry? A, hl
  • Which findings would you expect in lung function tests in COPD? Hl

Diagnosis

  • Why it is COPD? A
  • What are the differential diagnoses of COPD? A
  • Why not this is a case of chronic bronchitis? A
  • Why is this not bronchial asthma? hl
  • What is the basic difference between bronchial asthma and COPD? A
  • What are the differences between emphysema and chronic bronchitis? Hl
  • How to confirm your diagnosis? a

Treatment

  • How to manage COPD? A, hl
  • How domiciliary oxygen is given? What is the aim of the therapy? A
  • What is the role of inhaled steroid in COPD? A
  • What is the role of oral steroid in COPD? What are the indications of steroid in COPD? A, hl
  • What are the surgical treatments for COPD? Hl
  • What is the prognosis of COPD? A
  • How to manage acute exacerbation of COPD (type II respiratory failure)? A, hl
  • What are the indications for hospitalization? Hl
  • What are the principles of O2 therapy in respiratory failure? hl
  • Why low concentration O2 given in COPD? Or what happens when high flow O2 given? A, hl
  • What are the discharge criteria of COPD patient? A, hl
  • What is the new method used to assess prognosis of COPD patient? Hl
    • What is BODE index? Hl

Complications

  • What are the complications of COPD? A, hl

Rimikri

SOLVES


Definition and Classification
What is COPD?

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease characterised by persistent airflow limitation that is usually progressive, and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases.

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 673
What are the components of COPD?

The components of COPD are:

  • Chronic bronchitis
  • Emphysema.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 235
Define chronic bronchitis.

Chronic bronchitis is defined as cough and sputum on most days for at least 3 consecutive months for at least 2 successive years.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 235
Define emphysema.

Emphysema is defined as abnormal permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 235
Define airflow obstruction.

FEV1< 80% predicted and FEV1: FVC<70%.

  • FEV1 = Forced expiratory volume,
  • FVC = Forced vital capacity
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 235
What are the stages or classification of COPD?

Figure: Spirometric classification of COPD severity based on post-bronchodilator FEV1
* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 675
Define respiratory failure.

When pulmonary gas exchange fails to maintain normal arterial oxygen and carbon dioxide levels is termed respiratory failure.

* Pre-exam preparation for medicine, HN Sarker
What are the types of respiratory failure?

Type I and II relates to the absence or presence of hypercapnia (raised PaCO2)

  1. Type I respiratory failure (PaO2<8 and PaCO2<6.6)
  2. Type II respiratory failure (PaO2<8 and PaCO2>6.6).
* Pre-exam preparation for medicine, HN Sarker
Epidemiology
How many smokers are susceptible to develop COPD?

15% of smokers are susceptible to develop COPD.

* Pre-exam preparation for medicine, HN Sarker
Etiology and Pathophysiology
What are the mechanisms of airflow limitation in COPD?

As follows:

  • Increased mucus production and reduced mucocilliary clearance
  • Loss of elastic recoil
  • Increased muscle tone
  • Pulmonary hyperinflation.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 79
Is airflow obstruction reversible in COPD?

Airflow obstruction in emphysema is irreversible but in chronic bronchitis there is some degree of reversibility of airflow obstruction due to presence of inflammation.

* Pre-exam preparation for medicine, HN Sarker
What are the risk factors or causes of COPD?
  • Environmental
    • Tobacco smoke accounts for 95% of cases in UK
    • Indoor air pollution; cooking with biomass fuels in confined areas in developing countries
    • Occupational exposures, such as coal dust, silica and cadmium
    • Low birth weight may reduce maximally attained lung function in young adult life
    • Lung growth: childhood infections or maternal smoking may affect growth of lung during childhood, resulting in a lower maximally attained lung function in adult life
    • Infections: recurrent infection may accelerate decline in FEV1; persistence of adenovirus in lung tissue may alter local inflammatory response, predisposing to lung damage; HIV infection is associated with emphysema
    • Low socioeconomic status
    • Cannabis smoking
  • Host factors
    • Genetic factors: α1-antiproteinase deficiency; other COPD susceptibility genes are likely to be identified
    • Airway hyper-reactivity
* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 674
How much smoking accounts for COPD?

At least 10 pack years (1 pack year = 20 cigarets/day/year).

* Pre-exam preparation for medicine, HN Sarker
What organisms are associated with acute exacerbation of COPD?
  • Common organisms: Haemophilus influenzae and Streptococcus pneumoniae.
  • Other less common organisms are Moraxella catarrhalis, Chlamydia pneumoniae and Pseudomonas aeruginosa.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 80
What are the patterns of emphysema?

Centriacinar, panacinar, and periacinar.

* Pre-exam preparation for medicine, HN Sarker
What are the causes of type I respiratory failure?

The causes of type I respiratory failure are:

  • Acute asthma
  • Emphysema
  • Pulmonary edema
  • Pneumonia
  • Lung fibrosis.
* Pre-exam preparation for medicine, HN Sarker
What are the causes of type II respiratory failure?

The causes of type II respiratory failure are:

  • Acute severe asthma
  • COPD
  • Ankylosing spondylitis
  • Kyphoscoliosis.
* Pre-exam preparation for medicine, HN Sarker
Clinical Manifestations
What are the presentations of COPD?

Usually the patient is above 40 years, male and smoker. There is:

  • Chronic cough and sputum production, which is progressively increasing
  • Progressive breathlessness
  • There may be hemoptysis, edema and morning headache (due to hypercapnia).
* Long Cases in Clinical Medicine, ABM Abdullah Page: 79
Tell the MRC grading of dyspnea.

See more about dyspnoea at presenting problems of respiratory system

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 674
What are the extrapulmonary manifestations (systemic features) in COPD?
  • Muscular weakness reflecting deconditioning and cellular changes in skeletal muscles
  • Increased circulating inflammatory markers
  • Impaired salt and water excretion leading to peripheral oedema
  • Altered fat metabolism contributing to weight loss
  • ↑ Prevalence of osteoporosis

Figure: The pulmonary and systemic features of COPD.
* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 673
Examination
What findings can you get by examining this patient?

General examination

  • Patient is dyspneic.
  • Pursed-lip breathing.
  • Cyanosis
  • Respiratory rate is 30/min

Examination of the chest

  • Inspection
    • The chest is barrel shaped.
    • Excavation of supraclavicular and suprasternal fossae.
    • Indrawing of costal marginson inspiration (due to low flat diaphragm), and intercostals spaces.
    • Prominent accessory muscles (e.g.sternomastoid and scalene muscles) of respiration.
  • On palpation:
    • Trachea, central, tracheal tug is present (descent of trachea during inspiration).
    • Cricosternal distance (distance between suprastemal notch and cricoid cartilage) is reduced (normally three fingers or more).
    • Apex beat is not felt.
    • Chest expansion is reduced and chest movement is vertical.
    • Vocal fremitus is reduced on both sides.
  • On percussion:
    • Increased resonance or hyperresonance in both lung fields.
    • Obliteration of liver and cardiac dullness (liver dullness may be lower down)
  • On auscultation:
    • Breath sound, diminished; but vesicular with prolonged expiration.
    • Low or medium-pitched rhonchi may be present, if associated with chronic bronchitis.
    • Vocal resonance normal.
* Pre-exam preparation for medicine, HN Sarker; Short Cases in Clinical Medicine, ABM Abdullah, 5th Edition Page: 157
How can you predict acute infective exacerbation?

We can predict acute infective exacerbation by—

  • Increased breathless and cough
  • Increased sputum volume and purulence
  • Fever
* Pre-exam preparation for medicine, HN Sarker
Investigations
What investigations should be done in COPD?
  • Blood
    • complete blood count (CBC),
    • erythrocywe sedimentation rate (ESR),
    • packed cell volume (PCV)
  • X-ray chest posteroanterior (PA) view
  • Electrocardiogram (ECG)
  • Arterial blood gas (ABG)
  • Sputum-microscopy (culture and sensitivity)
  • Lung function test
  • High-resolution computed tomography
  • α-antitrypsin level.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236

 

Tell the radiological findings in COPD.

Emphysema

The radiological findings in COPD are:

  • Hyperinflated lung field
  • Low flat diaphragm
  • Long tubular heart shadow
  • Hyperlucent lung fields
  • Horizontal ribs
  • Widened intercostal spaces
  • Roomy apex
  • Emphysematous bullae
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236; Short Cases in Clinical Medicine, ABM Abdullah, 5th Edition Page: 158

 

What may be the ECG findings in COPD?

The ECG findings in COPD are:

  • Right ventricular hypertrophy +/– strain
  • Right atrial hypertrophy (P pulmonale)
  • Multifocal atrial tachycardia.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236
What may be the ABG abnormalities in COPD?
  • Type II respiratory failure (PaO2 <8 and PaCO2 >6.6) in chronic bronchitis.
  • Type I respiratory failure (PaO2 <8 and PaCO2 <6.6) in emphysema.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236
What are the findings in spirometry?

As follows:

  • FEV1 < 80% predicted
  • FEV1 : FVC < 70% predicted
  • Bronchodilator reversibility test shows <15% increase in FEV1  after giving bronchodilator.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 79
Which findings would you expect in lung function tests in COPD?
  • FEV1<80% predicted and FEV1: FVC<70% (airflow obstruction)
  • ↑ Total leukocyte count (TLC), functional residual capacity (FRC) and residual volume
  • ↓ Vital capacity(VC)
  • ↓ TLCO (carbon monoxide transfer factor).
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 237
Diagnosis
Why it is COPD?

The patient is a heavy smoker, taking … cigarettes a day for … years, there is chronic cough with breathlessness, which is progressively increasing day by day.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 78
What are the differential diagnoses of COPD?

As follows:

  • Chronic severe or persistent bronchial asthma
  • Bronchiectasis
  • Chronic bronchitis
  • Congestive cardiac failure.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 78
Why not this is a case of chronic bronchitis?

Because chronic bronchitis is defined as the presence of cough with sputum, not attributable to other causes, on most of the days of at least 3 consecutive months for 2 successive years.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 78
Why is this not bronchial asthma?
What is the basic difference between bronchial asthma and COPD?

Bronchial asthma is reversible, but COPD is not fully reversible and it is progressive.

See full difference at Bronchial asthma

* Long Cases in Clinical Medicine, ABM Abdullah Page: 78
What are the differences between emphysema and chronic bronchitis?
Feature Chronic bronchitis Emphysema
Diagnosis Clinical Pathological
Appearance Blue bloater Pink puffer
Cyanosis Prominent Absent
Hyperinflation + ++
Dyspnea + ++
Cough ++ +
Corpulmonale ++ +
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236
How to confirm your diagnosis?

By spirometry and reversibility test.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 94
Treatment
How to manage COPD?

General measures

  • Stop smoking completely and permanently.
  • Vaccination for influenza and pneumococcal pneumonia.

Drug therapy

  1. Mild COPD
    • Short-acting bronchodilators, such as the β2-agonists salbutamol or the anticholinergic, ipratropium bromide, as needed.
  2. Moderate COPD
    • Regular short-acting bronchodilators (alone/combination) +
    • Longer-acting bronchodilators, such as the β2- agonists salmeterol and formoterol, or the anticholinergic tiotropium bromide (alone/combination)
  3. Severe COPD
    • Short-acting bronchodilators (alone/combination) +
    • Longer-acting bronchodilators, such as the b2- agonists salmeterol and formoterol, or the anticholinergic tiotropium bromide(alone/combination) +
    • Inhaled corticosteroids (ICS) if two or more exacerbations requiring antibiotics or oral steroids per year. +/–
    • Oral theophylline.

Figure: Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines for treatment of COPD.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 237; Figure: Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 676
How domiciliary oxygen is given? What is the aim of the therapy?

Oxygen O2 is given 2 to 4 L/min for 15 hours/day by nasal prongs. The aim is to increase the PaO2 to at least 8 kPa (60 mm Hg) at sea level during rest or SaO2 to at least 90% (greater benefit may be seen in patients who receive > 20 hours per day).

Note: Regarding air travel:

  • Preflight assessment should be done by spirometry and hypoxic challenge test with 15% oxygen. If saturation is maintained >90%, the patient can be allowed to travel. If not, air travel should be avoided or undertaken only with inspired oxygen therapy.
  • Sufficient supplementary oxygen should be given during flight to keep the PaO2 above 50 mm Hg, which is achieved by increasing the flow by 1 to 2 L/min.
  • Patient who use to take continuous oxygen at home will require this supplementation.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 81
What is the role of inhaled steroid in COPD?

Inhaled steroid is recommended for symptomatic patient with moderate to severe COPD and for patients with frequent exacerbations, but not in mild COPD. It reduces the frequency and severity of exacerbation. There is small improvement of FEV1, but it does not alter the natural history of FEV1 decline.

* Long Cases in Clinical Medicine, ABM Abdullah Page: 82
What is the role of oral steroid in COPD? What are the indications of steroid in COPD?
What are the surgical treatments for COPD?

Bullectomy, lung volume reduction surgery (LVRS), and lung transplantation.

* Pre-exam preparation for medicine, HN Sarker
How to manage acute exacerbation of COPD (type II respiratory failure)?

Home management: Mild to moderate exacerbation by the use of

  • Increased bronchodilator therapy
  • A short course of oral corticosteroids
  • Antibiotics if appropriate.

Hospitalization

  • Oxygen 24% or 28% (Continuous low concentration oxygen via Venturi mask)
  • Bronchodilators: Nebulized short-acting β2-agonists combined with an anticholinergic agent (e.g. salbutamol with ipratropium).
  • Corticosteroids: Oral prednisolone—30 mg daily for 10 days.
  • Antibiotics: Amoxicillin or macrolide.
  • Respiratory support: Noninvasive ventilation for severe hypercapneic respiratory failure (pH<7.35)
  • Respiratory stimulant, i.e. doxapram if noninvasive ventilation is not available.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 237; Long Cases in Clinical Medicine, ABM Abdullah Page: 82
What are the indications for hospitalization?

The indications for hospitalization are:

  • Cyanosis
  • Peripheral edema
  • An alteration in consciousness
  • Comorbidity
  • Social isolation.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 237
What are the principles of O2 therapy in respiratory failure?

The principles are:

  • In type I, high concentration (i.e.>35%, usually 60%)/high flow (6–8 L/min)
  • In type II, low concentration (24%–28%)/low flow(1–2L/min).
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236
Why low concentration O2 given in COPD? Or what happens when high flow O2 given?
  • A small percentage of patients with severe chronic COPD and type II respiratory failure develop abnormal tolerance to raised PaCO2.
  • The patient may become dependent on hypoxic drive for respiration
  • High flow oxygen blunts the chemoresponsiveness of the respiratory center in the medulla (part of the brainstem) and thus aggravates respiratory failure (Type 2 respiratory failure).
  • To avoid this, in these patients, lower concentrations of oxygen 24%–28% by Venturi mask should be used to avoid precipitating worsening respiratory depression.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 236; Long Cases in Clinical Medicine, ABM Abdullah Page: 83
What are the discharge criteria of COPD patient?

When the patient is clinically stable on his or her maintenance medication.

* Short and Long Cases in Clinical Medicine, HN Sarker Page: 237
What is the prognosis of COPD? / What is BODE index?
  • The prognosis is inversely related to age and directly related to the post-bronchodilator FEV1.
  • A composite score comprising the body mass index (B), the degree of airflow obstruction (O), a measurement of dyspnoea (D) and exercise capacity (E) may assist in predicting death from respiratory and other causes.
  • Respiratory failure, cardiac disease and lung cancer represent common modes of death.

* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 677
Complications
What are the complications of COPD?

The complications of COPD are:

  • Pulmonary hypertension
  • Cor pulmonale
  • Respiratory failure
  • Polycythemia
  • Pneumothorax
  • Secondary infection.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 237
Notes
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