Respiratory

Question 1

Where does deoxygenated blood come from that results in a slightly lower partial pressure of oxygen after alveolar equilibration in the pulmonary capillaries?

Answer 1

Bronchial circulation and small cardiac (thesbian) veins that drain into the left atrium and left ventricle (shunting)

Question 2

What is molecularly wrong in patients with CF?

Answer 2

delta F508 resulting in a misfolded protein. encdoes an ATP gated chloride chanel that secretes chloride in lungs and GI tract. and reabsorbs CL in sweat glands. Misfolded protein is retained in the RER and not transported to the cell membrane

Question 3

What are the clinical findings in a fat embolus?

What does it look like on histology?

Answer 3

Etiology: long bone and pelvic fractures or orthopedic procedures. Associated with TRIAD of hypoxemia, neurological symptoms, (altered mentation, seizures) and petechial rash (head, neck, thorax, axila)

On histology, the fat emboloi look black due to staining with osmium tetroxide

Question 4

What are the clinical findings in a pulmonary embolism?

Answer 4

V/Q mismatch associated with sudden onset dyspnea, chest pain, tachypnea, tachycardia

Question 5

What are the findings in CREST syndrome?

Answer 5

=Scleroderma, localized subtype . 
C: calcinonsis
R: raynaud phenomenon
E: esophageual dysmotility 
S: sclerodactyly
T: telangiectasis of the skin

Due to thickening of vasculature, pulmonary arteries develop increase in pressure (shown be accentuated S2 sound) and results on cor pulmonale, or right sided congestive hear failure

Question 6

What are the findings in acute respiratory distress syndrome and what are the causes?

Answer 6

Etiology: SPARTAS
S: sepsis
P: pancreatitis
A: aspiration
R: uRemia
T: trauma
A: amniotic fluid embolism
S: shock 

endothelial damage in the pulmonary vasculature results in increased alveolar capilary permeability, protein rich leakage into alveoli (exudate) , diffuse alveolar damage and NONCARDIOGENIC pulmonary edema (therefore pcwp is normal)

Presentation: acute respiratory failure, bilateral lung opacities, low PaO2/FIO2, no evidence of HF or fluid overload.

Results in formation of intra alveolar hyaline membranes and intial damage is due to neutrophils and activation of coagulation cascade and oxygen derived free radicals

Question 7

What disease presents in young women with an insidious onset of respiratory symptoms accompanied by fatigue, fever and weight loss with a characteristic histopathologic picture of aggregates of non caseating granulomas of epitheolioid macrophages and multinucleated giant cells

Answer 7

Sarcoidosis! A characteristic restrictive lung disease

Question 8

What is a bronchial hamartoma?

Answer 8

Benign coin lesion (solitary nodule), composed of lung tissue and cartilage

Composed of disorganized cartilage, fibrous, and adipose tissue

Question 9

What is aspiration pneumonia and what causes it?

Answer 9

Seen in patients at risk for aspiration such as alcoholics or comatose patients or bronchial obstruction such as a cancer.
Due to anaerobic bacteria on the oropharynx such as bacteroides, fusobacterium, peptostreptocccus or staph aureus.

Classically results in a right lung abscess (seen by air fluid level on CXR)