Pulmonary Vascular Disease

Question 1

Pulmonary Embolism Causes

Answer 1

Venous thrombosis (lower extremities or pelvis),
fat, amniotic fluid, clumps of tumour cells or bone marrow

Question 2

Pulmonary Embolism Risk factors

Answer 2

Stasis of blood flow (prolonged bed rest or
immobilisation), hypercoagulable states, use of oral
contraceptives

Question 3

Saddle embolus

Answer 3

Large emboli → Major vessels

Question 4

Clinical finding of Saddle embolus

Answer 4

Sudden increase in Pulmonary Artery pressure
Acute right ventricular strain → Sudden death

Question 5

Clinical findings of Pulmonary infarction

Answer 5

Sudden onset of dyspnoea and tachypnoea
Pleuritic chest pain
Friction rub
Effusion
Expiratory wheezing

Question 6

Laboratory Findings of pulmonary embolism

Answer 6

Respiratory alkalosis (arterial PCO2 <33 mmHg)
PaO2 <80 mmHg (90% of cases)
Increase in Alveolar - arterial gradient (100% of cases)
Increase in D-dimers
✓Positive D-dimers

Question 7

Chest X-ray of pulmonary embolism

Answer 7

Elevation of ipsilateral hemi-diaphragm
Pleural effusion (haemorrhagic)
Westermark’s sign of peripheral oligaemia
Fleischner’s sign of “amputated” pulmonary artery
Hampton hump (wedge-shaped area of
consolidation)

Question 8

Ventilation scan will be _______ in pulmonary embolism

Answer 8

Normal

Question 9

Perfusion Radionuclide Scan

Answer 9

Abnormal

Question 10

What is the Gold standard
confirmatory test of pulmonary embolism?

Answer 10

Pulmonary angiogram

Question 11

Macro-/Microscopic finding in pulmonary embolism

Answer 11

Red-blue raised wedge-shaped area that extends to
the pleural surface
Majority are located in the lower lobes (Perfusion >
Ventilation)
Fibrinous exudate on pleural surface
Haemorrhagic pleural effusion

Question 12

Mean pulmonary artery pressure >25mmHg
at rest (normal: 15 mmHg) >30mmHg
with exercise (normal: 20 mmHg)

Answer 12

Pulmonary Hypertension

Question 13

Histologic picture of pulmonary hypertension

Answer 13

Characteristic plexiform lesions

Question 14

Which form of pulmonary hypertension is more common?

Answer 14

Secondary pulmonary hypertension

Question 15

Pathogenesis of 2nd pulmonary hypertension

Answer 15

Endothelial cell dysfunction ->Loss of vasodilators (e.g. NO) -> Increase in vasoconstrictors (e.g. Endothelin)
Hypoxaemia & Respiratory Acidosis → Pulmonary
arteries vasoconstriction → Smooth muscle
hyperplasia and hypertrophy

Question 16

Causes of 2nd pulmonary hypertension

Answer 16

Chronic hypoxaemia (e.g. Chronic lung disease)
Chronic respiratory acidosis (e.g. Chronic bronchitis)
Loss of pulmonary vasculature → Workload for
remaining vessels (e.g. Emphysema, recurrent
pulmonary emboli)
Left-to-right cardiac shunts → Volume overloading
pulmonary vasculature
Left-sided valvular disease (e.g. Mitral stenosis) →
Backup of blood into pulmonary veins → Venous
hypertension

Question 17

Histologic picture of 2nd pulmonary hypertension

Answer 17

Atherosclerotic changes of main pulmonary
arteries (Result of ↑ pressure to endothelium →
Endothelial injury)
Proliferation of myo-intimal and smooth muscle
cells

Question 18

Intra-alveolar accumulation of fluid

Answer 18

Pulmonary Oedema

Question 19

Pathogenesis of pulmonary oedema

Answer 19

Due to alterations in Starling forces (transudate)
Due to micro-vascular or alveolar injury (exudate)
Increased alveolar capillary permeability

Question 20

Causes of Adult Respiratory Distress Syndrome

Answer 20

Shock, sepsis, trauma, uraemia, aspiration of
gastric contents, acute pancreatitis, inhalation of chemical irritants, oxygen toxicity, heroin, bleomycin

Question 21

Pathogenesis of Adult Respiratory Distress Syndrome

Answer 21

Damage to alveolar capillary endothelium and alveolar epithelium (Diffuse alveolar
damage) → ↑ in alveolar capillary permeability →
Leakage of protein-rich fluid into alveoli

Question 22

Pathogenic factors of Adult Respiratory Distress Syndrome

Answer 22

Neutrophils → Release of substances, toxic to
alveolar wall
Activation of coagulation cascade → Micro-emboli
Oxygen-derived free radicals → Oxygen toxicity

Question 23

ARDS can be a manifestation of

Answer 23

Severe Acute Respiratory Syndrome

Question 24

SARS Coronavirus destroys

Answer 24

type II pneumocytes and causes diffuse alveolar damage

Question 25

Clinical Features of ARDS

Answer 25

Impairment of respiratory gas exchange → Severe hypoxia

Question 26

Histopathological features of ARDS

Answer 26

Formation of intra-alveolar hyaline membranes (fibrin and cellular debris)

Question 27

Hyaline Membrane Disease

Answer 27

Neonatal Respiratory Distress Syndrome

Question 28

Most common cause of respiratory failure in newborns
Most common cause of death in premature infants

Answer 28

Neonatal Respiratory Distress Syndrome

Question 29

Cause of Neonatal Respiratory Distress Syndrome

Answer 29

Deficiency of surfactant, due to immaturity

Question 30

Clinical Features of NRDS

Answer 30

Dyspnoea
Cyanosis
Tachypnoea

Question 31

What secretes surfactant?

Answer 31

Type II pneumocytes

Question 32

What does surfactant do?

Answer 32

Reduces surface tension within the lung →
Facilitates expansion during inspiration and
prevents atelectasis during expiration

Question 33

Predisposing factors of NRDS

Answer 33

Prematurity
Maternal Diabetes Mellitus
Birth by caesarian section

Question 34

Macro\Micro of NRDS

Answer 34

Heavy lungs, with alternating areas of atelectasis
and alveolar or alveolar-ductal dilatation
Engorgement of small pulmonary vessels
Leakage of blood products into the alveoli →
Formation of intra-alveolar hyaline membranes
(fibrin and cellular debris)

Question 35

Complications of NRDS

Answer 35

Broncho-Pulmonary Dysplasia: Result of treatment
with high-concentration oxygen and mechanical
ventilation
Patent ductus arteriosus: Due to immaturity and
hypoxia
Intra-ventricular brain haemorrhage
Necrotising Enterocolitis: Fulminant inflammation of
the small and large intestines