This document discusses various lung vascular diseases, including pulmonary edema, pulmonary congestion, pulmonary thrombosis, pulmonary embolism, pulmonary infarction, adult respiratory distress syndrome (ARDS), and pulmonary hypertension. It provides details on the causes, pathophysiology, and characteristics of each condition. Pulmonary edema can result from elevated pulmonary hydrostatic pressure due to conditions like heart failure or increased capillary permeability from infections or toxins. Pulmonary thrombosis is uncommon but can be due to atherosclerosis or pulmonary hypertension. ARDS is caused by diffuse alveolar damage and has many potential causes including shock, trauma, infections, and inhalation of irritants. Pulmonary hypertension can be primary or secondary to heart or lung lesions.

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LUNG VASCULAR
DISEASES
MWAKIGONJA, Amos Rodger: MD, MMed, PhD,
FCPath ECSA
Consultant Pathologist & Senior Lecturer
School of Medicine (SoM)
MUHAS

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Introduction
 Diseases of the heart affect the lungs &
vice versa.
 Pressure in pulmonary arteries is
lower<systemic.
 Pulmonary arteries thinner than systemic
 Elastic vessels

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Introduction
 Generally pulmonary vascular d’ses are:
 Pulmonary oedema
 Pulmonary congestion
 Pulmonary thrombosis
 Pulmonary embolism
 Pulmonary infarction
 Specific forms
 Adult respiratory distress syndrome (ARDS)
 Pulmonary hypertension

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Pulmonary oedema
 Can result from
 elevated pulmonary hydrostatic pressure
 Increased capillary permeability
1. Elevated pulmonary hydrostatic
pressure:
 Heart failure (LVF), MS, pul vein obstr,
thyrotoxicosis:
 incr. Pressure in pulmonary veins, interstitial
oedema, alveolar destruction, alveolar
oedema.

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Pulmonary oedema
2. Irritant oedema:
 Incr. Vascular permeability due to damage
 Infections, toxins, aspiration, shock,
radiation, hypersensitivity, uraemia, ARDS.
3. Acute high altitude oedema:
 Sudden climb >2500m, oedema, congestion,
haemorrhages
 Anoxic damage to pulmonary vessels.

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Pulmonary congestion
 Chronic venous congestion of lung
 LVH, MS
 Interstitial oedema, dilated, congested
capillaries,
 +/- rupture=minute haemorrhages
 Heart failure cells

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Pulmonary thromboembolism
 Most c’mon, fatal venous thromboembolism
 Pulmonary thrombosis is unc’mon, due to
atherosclerosis, PHT
 Etiology:
 Prolonged immobilization-hospitalization,
 DVT-long flights
 Varicosities
 Saddle embolus, multiple, paradoxical

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Pulmonary thromboembolism
 Consequences
 Depends on size of vessel, number of emboli,
CVS status
 Sudden death
 Acute cor pulmonale
 Haemorrhage
 Resolution
 PHT, chronic cor pulmonale, pulmonary
arteriosclerosis.

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Pulmonary infarction
 May result from pulmonary embolism.
 Lungs have double circulation.
 Often in lower lobes, on base of pleura
 Fibrinous pleuritis
 Coagulative necrosis of alveolar walls
 Neutrophils, vasocongestion
 Later haemosiderin, phagocytes,
granulation

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ARDS
 Also shock-lung syndrome, diffuse alveolar
damage (DAD), acute alveolar injury,
traumatic wet lungs, post-traumatic
respiratory insufficiency.
 Caused by diffuse alveolar damage
 Sudden & severe resp distress,
tachypnoea, tachycardia, cyanosis, failure
to respond to oxygen therapy unlike
neonatal RDS.

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ARDS
 Causes:
 Shock due to sepsis, trauma, burns
 Diffuse pulmonary infxns esp viral
 Pancreatitis
 Oxygen toxicity
 Inhalation of toxins & irritants
 Narcotics overdose
 Drugs eg salicylates, colchicine
 Aspiration
 Fat embolism
 Radiation

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Pulmonary hypertension
 Primary or idiopathic
 Secondary to lesions in heart or lungs
