Respiratory Medicine Made Simple: COPD / Chronic Obstructive Airways Disease

Get 23 % Discount on Dr Najeebs Lectures Life time Subscription at just 79 US Dollars. Go to the following Link: https://members.drnajeeblectures.com/#!/registration Fill in the details and enter Affiliate ID for discount : 1095912 and clickon Apply Affiliate Discount button during checkout to get a 23% discount for life subscription at a very reduced cost


COPD/CHRONIC OBSTRUCTIVE PULMONARY DISEASE

COPD is a common progressive disorder characterized by airway obstruction with little or no reversibility.

It includes 2 diseases :

Chronic bronchitis and Emphysema

CHRONIC BRONCHITIS:

This is clinically defined as cough and sputum production on most days for 3 months of 2 successive years.

Symptoms improve when patients stop smoking.

EMPHYSEMA:

This is defined as enlarged air spaces distal to terminal bronchioles with destruction of alveolar walls.

COPD GENERAL CONSIDERATIONS:

FEV1 ( Forced Expiratory Volume in 1 second ) is less than 80 % predicted and FEV1/FVC is less than 0.7

COPD  is usually seen in smokers and air pollution is also an important contributory factor.

Age of onset is usually > 35 years

There is minimal day to day variation.

Patients present with Chronic Dyspnoea

SYMPTOMS:

Cough

Increased sputum production.

Dyspnoea

Wheeze

SIGNS:

Tachypnoea

Cyanosis

Use of accessory muscles of respiration.

Hyperinflation of chest

Reduced cricosternal distance < 3 cm

Reduced chest expansion.

Hyperresonant percussion note

Quiet breath sounds

INVESTIGATIONS:

FBC : Increased WCC and PCV

CXR :

Hyper inflation (> 6 anterior ribs seen above diaphragm in mid-clavicular line)

Flat hemidiaphragms

Large central pulmonary arteries

Decreased pulmonary vascular markings

Bullae

ECG:

Right axis deviation,

Right ventriucular hypertrophy/cor pulmonale.

ARTERIAL BLOOD GASES :

Low PaO2 and Increased PaCO2.

LUNG FUNCTION TESTS:

Obstructive and air trapping

FEV1 <  80 % of predicted

FEV1/FVC < 70% predicted

Raised TOTAL LUNG CAPACITY

Raised RESIDUAL VOLUME

COMPLICATIONS:

Acute exacerbations +/- Infections

Respiratory Failure

Polycythemia

Cor pulmonale

Pneumothorax

Lung carcinoma

MANAGEMENT/BTS GUIDELINES:

ASSESSMENT OF COPD:

Spirometry

Bronchodilators may improve FEV1 slightly.

Trial of steroids : Look for > 15 % increase in FEV1.

CXR : Bullae or any other pathology? Consolidation/Abnormal shadowing

SEVERITY OF COPD :

MILD: FEV1 :  50 – 80 % of predicted

MODERATE : FEV1 30 – 49 % of predicted

SEVERE : FEV1 < 30 % of predicted.

MANAGEMENT

TREATING  STABLE  COPD:

GENERAL MEASURES:

Stop smoking

Encourage exercise

Treat poor nutrition or obesity

Influenza and pneumococcal vaccinations.

Pulmonary rehabilitation/palliative care.

NIPPV : NON  INVASIVE  INTERMITTEMT POSITIVE  PRESSURE  VENTILATION

MILD COPD:

ANTIMUSCARINICS : Ipratropium or BETA 2 AGONIST inhalations :Salbutamol as per need

MODERATE: Regular anticholinergic eg Ipratropium or Tiotropium or Long acting beta 2 agonists such as salmetrol + inhaled corticosteroids esp if FEV1 < 50 % and more than or equal to 2 exacerbations / year.

SEVERE : LABA + INALED STEROIDS + ANTICHOLINERGICS AND SPECIALIST REFERRAL

PULMONARY HYPERTENSION:

Treat Oedema with Diuretics,Assess the need for LTOT

MORE ADVANCED COPD:

PULMONARY REHABILITATION

LONG TERM OXYGEN THERAPY TO MAINTAIN PAO2 > 8.0 Kpa for more than 15 hours a day.

LTOT should be used if PaO2 < 7.3 kpa

INDICATIONS FOR SURGERY:

Recurrent pneumothoraces

Isolated bullous disease

Lung volume reduction surgery

NIV in case of severe diasese

PINK PUFFERS AND BLUE BLOATERS:

These are two variants seen in COPD

PINK PUFFERS:

They have increased alveolar ventilation,a near normal PaCO2 or low PaCO2.

They are breathless but not cyanosed.

They may progress to Type 1 Respiratory failure

BLUE BLOATERS:

They have reduced Alveolar ventilation.

There is low PaO2 and high PaCO2.

They are cyanosed but not breathless and may go on to develop cor-pulmonale.Thir respiratory centres are relatively insensitive to CO2 and they rely on hypoxic drive to maintain respiratory effort.

Hence supplemental oxygen should be given with care.