Resp path -congenital disorders & atelectasis Flashcards
What is pulmonary hypoplasia?
: Decreased lung size due to defect in lung development, caused by
compression / restricted expansion of the lung in utero e.g. congenital diaphragmatic hernia,
Oligohydramnios
What are foregut cysts?
: From abnormal detachment of the primitive foregut. Incidental or cause symptoms
due to compression of adjacent structures or superimposed infection
What is pulmonary sequestration?
Lung tissue not connected to the airways and has abnormal blood supply
arising directly from the aorta or its branches. Can be extralobar or intralobar
What is neonatal atelectasis?
Incomplete lung expansion or collapse of a previously inflated lung, leading to poorly aerated lung tissue, which reduces oxygenation and predisposes to infection
In what instances is neonatal atelectasis irreversible?
When it is caused by fibrosis (scarring of the lung tissue), which can make the lung less elastic and less likely to expand fully.
What are the consequences of unaerated collapsed lung?
-Causes ventilation/perfusion mismatch, acting as a shunt similar to a cardiac right-to -left shunt that bypasses the lungs, with blood gas parameters from collapsed lung approaching the mixed venous blood entering the right heart.
What is resorption atelectasis?
It is due to airway obstruction (e.g. excess mucus, exudate, foreign bodies, tumours). The obstruction causes resporption of air from the distal alveoli that then collapse.
In resorption atelectasis, in which direction will the mediastinum shift?
It will shift towards the collapsed lung due to a reduction in volume
What is compression atelectasis?
Due to accumulation of fluid, air, or tumors within the pleural cavity
In which direction will the mediastinum shift in compression atelectasis?
Away from the atelectatic lung
What is contraction atelectasis?
Due to focal or generalized pulmonary or pleural fibrosis preventing full lung expansion
