Pulmonary Flashcards
What is primary HTN most often associated with?
An inactivation mutation of BMPR2, which leads to proliferation of vascular smooth muscle.
On the histology, what is a sign of long-standing pulmonary HTN?
Plexiform lesion - a tuft of capillaries that occurs together
What type of pneumoconiosis predisposes a person to Tb and why?
Silicosis because silica impairs phagolysosome formation by macrophages, leading to increased risk of Tb.
What is the primary driver of pneumocytes to induce fibrosis?
TGF-Beta - remember macrophages induce fibrosis as the healing process by releasing TGF-beta and IL-10.
Why do people with sarcoidosis have hypercalcemia?
Granulomas have 1-alpha-hydroxylase activity activating vitamin D. Any disease with non-caseating granulomas will lead to hypercalcemia. You might see this with berylliosis as well.
What are two common causes of emphysema?
1) smoking 2) alpha-1-antitrypsin deficiency - both of these lead to destruction of alveolar air sacs and consequently loss of elastic recoil and airway collapse in the lung
What is cor pulmonale?
Blood vessels in lung vasoconstric when no ventilation, which shunts blood away. In a disease like chronic bronchitis, all vessels clamp down increasing the pressure that right ventricle must pump against, which can lead to RVH and eventually RH failure.
What other organ system beside the lung does A1AT deficiency affect?
The liver - it can lead to cirrhosis because the ER of hepatocytes get clogged up with misfolded A1AT proteins.
Why do patients with emphysema use purse lipped breathing?
This leads to an increase positive back pressure keeps the airways open in the lung, which is necessary since elastic recoil is damaged.
What class III anti-arrhythmic can lead to interstitial fibrosis?
Amiodarone
What are considered the stem cells of the lung?
Type II pneumocytes
What would be signs of endothelial cell damage in association with damage of the alveolar air sacs?
vWF and endothelin. Might also see LDH or D-dimer.
What is the cause of neonatal respiratory distress syndrome? How do you treat it?
Inadequate surfactant production by type II pneumocytes - treat with exogenous lecithin (AKA phosphatidylcholine)
When does surfactant production begin?
At 28 weeks of gestation but adequate levels not reached till 34 weeks. Premature babies before this are at risk of NRDS.
Why would you not want to give a baby suffering from NRDS supplemental O2?
This could lead to free radical formation which can damage the retina leading to blindness and bronchopulmonary dysplasia.
In terms of tracheal deviation, how do you differentiate between a spontaneous and tension pneumothorax?
Spontaneous pneumothorax has tracheal deviation towards the side with the damage. Tension pneumothorax has tracheal deviation away from the hole in the pleura (air get in the pleural space like a basketball and cannot escape so it “pumps” the tracheal away from the pneumothorax).
How would you treat an isoniazid overdose?
Pyridoxine - because INZ is a competitive antagonist of pyridoxal kinase, an essential component in the biosynthesis of GABA from vit B6 (pyridoxine)
What other signs or symptoms do patients with aspirin induced asthma often present with?
Also known as Samter’s triad: a combination of nasal polyps, asthma, and aspirin sensitivity.
In a patient with CF, the mutation results in a defect in which aspect of the CFTR protein assembl?
ER processing from the ER to the Golgi apparatus.
What is a Curschmann’s spiral?
Mucoid exudate forming a cast of the airways (associated with asthma)
What is a Charcot-Leyden crystal?
Collections of crystalloid made up of eosinophil membrane protein
If a patient has a sulfa allergy, what is the next best choice for prophylaxis of pneumocystis jirovecci?
Pentamidine (then dapsone)
What are the four major mechanisms of hypoxemia (PaO2 < 80 mmHg on room air)?
1) anatomic shunt
2) physiologic shunt (atelectasis)
3) low V/Q
4) hypoventilation
What are two mechanisms for hypercarbia (PaCO2 > 45)?
1) hypoventilation
2) increased dead space
Menthol acts on what channel to alleviate a cough?
TRPM8
What is the alveolar gas equation?
PAO2 = FiO2 (Pb - PH20) - (PACO2/0.8)
What is the O2 content equation?
Ca02 = (Hgb x 1.34) x SaO2 x Dissolved O2
What airways are flow dependent?
The large airways - greater effort = greater peak flow. Small airways are not flow dependent.
What are the 6 parameters of good effort on PFT?
1) Rapid rise on flow/volume curve
2) Early peak
3) Gradual decrease in flow to baseline
4) Plateau on spirogram
5) Expiratory time is > 6 sec.
What does the extent of restriction and obstruction depend on?
For restriction, extent depends on FVC. For obstructive, severity depends on FEV1.
What kind of breathing for those suffering from restrictive lung disease do?
Rapid, shallow breathing. This increase in frequency minimizes the work of breathing for individuals with a loss of lung compliance.
True or False: Idiopathic pulmonary fibrosis responds to corticosteroid therapy.
False - the only treatment is a lung transplant.
What lung disease is associated with honeycombing on a chest?
Idiopathic pulmonary fibrosis (this pattern is seen due to dense fibrosis)
What are the two most common causes of hypersensitivity pneumonitis?
1) Avian proteins found in bird excrement and feathers
2) Saccharopolyspora rectivirgula, a thermophilic actinomyces found in moldy hay.
Compared to normal, patients with a restrictive lung disease have a _______ RV/TLC.
Increased ratio; both are decreased though. TLC is decreased out of proportion to RV (remember this is a problem with filling)