BCR TBL 14 - Asthma, Obstructive, Restrictive Lung Disease and Lung Cancer

What is the most common origin of large pulmonary emboli?

Deep veins of the lower limbs (DVT)

What is the main physiological effect of a large pulmonary embolism?

Blockage of pulmonary arteries causing V/Q mismatch and hypoxaemia

Which imaging modality is the gold standard for diagnosing pulmonary embolism?

CT pulmonary angiography (CTPA)

What ECG pattern is classically associated with pulmonary embolism?

S1Q3T3 pattern

What blood gas abnormality is common in acute pulmonary embolism?

Respiratory alkalosis due to hyperventilation

What causes hypoxaemia in pulmonary embolism?

V/Q mismatch and shunting

What are common symptoms of pulmonary embolism?

Sudden dyspnoea, pleuritic chest pain, tachycardia

What distinguishes a pulmonary shunt from V/Q mismatch?

Shunt does not improve with oxygen therapy

What is the effect of a pulmonary shunt on PaO2?

Severe hypoxaemia unresponsive to O2

What defines a physiological shunt?

Perfusion without ventilation (e.g., atelectasis)

Which cells mediate the inflammatory response in asthma?

Eosinophils and mast cells

What is a diagnostic hallmark of asthma on spirometry?

Reversible airflow obstruction

Which test confirms reversibility in asthma?

Spirometry with bronchodilator response

What are common triggers for asthma exacerbations?

Cold air, allergens, exercise, infections

What symptom characterizes severe acute asthma?

Silent chest with no audible wheeze

What is the typical blood gas pattern early in asthma exacerbation?

Respiratory alkalosis

What does rising PaCO2 in asthma indicate?

Fatigue and impending respiratory failure

What is the key difference between asthma and COPD?

Asthma is reversible; COPD is not

What are the components of COPD?

Chronic bronchitis and emphysema

What defines chronic bronchitis clinically?

Cough with sputum for ≥3 months/year for 2 consecutive years

What is the hallmark of emphysema?

Destruction of alveolar walls leading to increased compliance

What spirometry pattern is seen in COPD?

Obstructive: ↓FEV1/FVC ratio

Which lung volume is increased in emphysema?

Residual volume (RV)

What gas exchange abnormality is common in COPD?

V/Q mismatch and hypoxaemia

What is the 'blue bloater' phenotype?

COPD with chronic bronchitis, cyanosis, CO2 retention

What is the 'pink puffer' phenotype?

Emphysema with dyspnoea and pursed-lip breathing

What is a common complication of chronic hypoxia in COPD?

Pulmonary hypertension

What is the histopathological feature of idiopathic pulmonary fibrosis (IPF)?

Fibroblastic foci and interstitial fibrosis

What lung sound is typical of interstitial lung disease?

Fine, bibasilar crackles

What is the hallmark imaging finding in IPF?

Honeycombing on high-resolution CT

What is the typical spirometry pattern in ILD?

Restrictive: ↓TLC and ↓FVC with normal or ↑FEV1/FVC

Which interstitial disease features granulomas?

Sarcoidosis

Which lung cancer is most common in non-smokers?

Adenocarcinoma

Which lung cancer is strongly associated with smoking?

Squamous cell carcinoma and small cell lung cancer

Which lung cancer has rapid progression and paraneoplastic syndromes?

Small cell lung cancer

What paraneoplastic syndrome is linked to small cell lung cancer?

SIADH or Cushing's syndrome

What is the main site of metastasis for lung cancer?

Brain, bone, liver, adrenal glands

What histological feature is seen in squamous cell carcinoma?

Keratin pearls and intercellular bridges

What is the function of the cough reflex?

Clear secretions and protect airway

Which cranial nerve mediates the cough reflex?

Vagus nerve (CN X)

Where are cough receptors primarily located?

Larynx, trachea, and large airways

Which muscle is essential for forceful coughing?

Rectus abdominis

What are common causes of acute cough?

Viral URTI, acute bronchitis

What are common causes of chronic cough?

Postnasal drip, asthma, GERD

What is a respiratory cause of chest pain?

Pulmonary embolism or pleuritis

What symptom suggests cardiac dyspnoea rather than respiratory?

Orthopnoea or paroxysmal nocturnal dyspnoea

What symptom suggests upper airway obstruction?

Stridor

What effect does smoking have on the respiratory epithelium?

Increased goblet cells, impaired cilia

How does smoking contribute to emphysema?

Increased elastase activity leading to alveolar destruction

What is the GOLD criteria used for?

Staging severity of COPD

What is the main effect of airway inflammation on resistance?

Increased resistance due to wall thickening and mucus

What is the formula for airway resistance?

R ∝ 1 / radius⁴

Which part of the airway contributes most to resistance?

Large central airways

What is the effect of restrictive disease on lung compliance?

Decreased compliance

What happens to total lung capacity in restrictive lung disease?

Decreased

What causes decreased DLCO in ILD?

Thickened alveolar-capillary membrane

What is a distinguishing feature of asthma in children?

Nocturnal coughing or exercise-induced symptoms

What is a key feature of asthma pathophysiology?

Type I hypersensitivity reaction (IgE-mediated)

What is the mechanism of action of beta-agonists in asthma?

Relax bronchial smooth muscle

What blood gas change occurs in early asthma?

Hypocapnia (low PaCO2)

What is the key mechanism of hypoxaemia in pneumonia?

Shunting due to non-ventilated alveoli

What is a common example of V/Q mismatch?

Pulmonary embolism

What is a key cause of increased work of breathing?

Increased airway resistance or decreased lung compliance

How is CO2 eliminated during rapid shallow breathing?

Inefficiently; may cause hypercapnia

Which condition is associated with normal PaO2 but increased A-a gradient?

Pulmonary embolism or shunt

What is the A-a gradient used to assess?

Efficiency of oxygen transfer from alveoli to blood

What does a high A-a gradient with normal PaCO2 suggest?

V/Q mismatch or shunt

Which respiratory disorder typically has increased lung compliance?

Emphysema

Which disorder leads to a decreased DLCO?

Interstitial lung disease, emphysema

What symptom is a red flag in chronic cough?

Hemoptysis

What does clubbing suggest in respiratory disease?

Lung cancer, bronchiectasis, ILD

What defines Type I respiratory failure?

Hypoxaemia (PaO2 < 60 mmHg) with normal/low PaCO2

What defines Type II respiratory failure?

Hypercapnia (PaCO2 > 50 mmHg)

What is orthopnea typically associated with?

Congestive heart failure

What is a key feature of asthma on peak flow monitoring?

Diurnal variability >20%

What causes hyperinflation in COPD?

Air trapping due to expiratory flow limitation

What is a cause of exertional dyspnoea in ILD?

Impaired oxygen diffusion

Which medication can cause chronic cough as a side effect?

ACE inhibitors

Which condition improves with bronchodilators: asthma or COPD?

Asthma

Which test measures diffusion capacity?

DLCO test (carbon monoxide diffusion)

What is the primary ventilatory defect in restrictive lung disease?

Reduced lung expansion

What are late signs of COPD?

Barrel chest, tripod positioning, use of accessory muscles

What causes the barrel chest appearance in emphysema?

Chronic hyperinflation

What is the mechanism of wheeze in asthma?

Turbulent airflow through narrowed bronchi

What is paradoxical breathing a sign of?

Respiratory muscle fatigue or failure

Which muscles assist with inspiration during respiratory distress?

Sternocleidomastoid, scalene muscles

Which test is useful in assessing response to asthma treatment?

Serial peak expiratory flow rate (PEFR)

What does increased work of breathing indicate clinically?

Potential impending respiratory failure

What are typical features of bronchiectasis?

Chronic productive cough, hemoptysis, recurrent infections

Which imaging is best for diagnosing bronchiectasis?

High-resolution CT scan

What is pulsus paradoxus a sign of in respiratory disease?

Severe asthma or cardiac tamponade

What are crackles in ILD caused by?

Opening of collapsed alveoli during inspiration

What is the role of eosinophils in asthma?

Release cytotoxic granules contributing to inflammation

Which condition is most commonly associated with pleuritic chest pain?

Pulmonary embolism or viral pleuritis

What are the four main lung volumes?

Tidal volume, inspiratory reserve, expiratory reserve, residual volume

What does FEV1/FVC ratio help distinguish?

Obstructive vs restrictive lung disease

What is a hallmark of obstructive lung disease?

FEV1/FVC < 70%

What does a normal FEV1/FVC with low TLC suggest?

Restrictive disease

What lung volume is not measured by spirometry?

Residual volume

What is the primary cause of mortality in COPD?

Respiratory failure or cardiovascular complications