Pulm Random Facts

Question 1

Relationship of the pulmonary artery to the bronchus at each lung hilm

Answer 1

RALS= Right anterior; left superior

Question 2

What goes through the diaphragm at T12?

Answer 2

Aorta, thoracic duct, and azygos vein

Question 3

What is the functional residual capacity?

Answer 3

Volume of gas in lungs after normal expiration (residual volume plus expiratory reserve volume)

Question 4

How to calculate physiologic dead space?

Answer 4

Tidal volume * (Paco2-Peco2)/Paco2; Paco2= arterial Pco2; Peco2=expired air Pco2

Question 5

What decreases pulmonary compliance?

Answer 5

Pulmonary fibrosis, pneumonia, pulmonary edema

Question 6

What increases pulmonary compliance?

Answer 6

Emphysema, normal aging

Question 7

What shifts the hemoglobin dissociation curve to the right?

Answer 7

Increased Cl, H+, CO2, 2,3-BPG, and temperature

Question 8

What is familial erythrocytosis?

Answer 8

A beta-globulin mutation that results in reduced binding of 2,3-BPG

Question 9

How to remember which is ferrous and which is ferric?

Answer 9

Just the two of us: ferroUS is Fe2+

Question 10

How much oxygen can 1 g of hemoglobin bind?

Answer 10

1.34 mL

Question 11

Which gases are perfusion limited?

Answer 11

O2 (normal health), CO2, N20

Question 12

Which gases are diffusion limited?

Answer 12

O2 (emphysema, fibrosis), CO.

Question 13

How do you calculate the pulmonary vascular resistance?

Answer 13

[P(pulm artery)-P(L atrium)]/cardiac output

Question 14

What is the alveolar gas equation?

Answer 14

PAo2=PIo2-(PaCO2/R); R is the respiratory quotient=CO2 produced/O2 consumed

Question 15

What can cause an A-a gradient?

Answer 15

V/Q mismatch, diffusion limitation (eg. fibrosis), right to left shunt

Question 16

What is the normal V/Q ratio at the apex and base of the lungs?

Answer 16

V/Q at apex=3 (wasted ventilation); V/Q=0.6 (wasted perfusion); BUT both ventilation and perfusion are greater at the base of the lung than at the apex

Question 17

Pressures in the apex of the lung

Answer 17

PA> Pa > Pv

Question 18

Pressures in zone 2 of the lung

Answer 18

Pa >PA> Pv

Question 19

Pressures in zone 3 (base) of the lung

Answer 19

Pa >Pv > PA

Question 20

What is the Bohr effect?

Answer 20

Increased Pco2 causes increased H+, which causes decreased hemoglobin affinity for O2 causing oxygen unloading

Question 21

What is the Haldane effect?

Answer 21

Increasing Po2 causes increased binding of O2 o Hb causing release of H+ and CO2

Question 22

Where does CO2 bind to hemoglobin

Answer 22

At the N-terminus of globin (NOT to heme)

Question 23

What happens in the kidney in response to high altitude?

Answer 23

Increased renal excretion of HCO3- to compensate for respiratory alkalosis (can augment with acetazolamide)

Question 24

Which bacteria may be superimposed on viral rhino sinusitis?

Answer 24

S. pneumo, H. flu, M. catarrhalis

Question 25

Where do life-threatening nose bleeds occur?

Answer 25

Posterior segment (sphenopalatine artery, a branch of maxillary artery)

Question 26

Classic triad of fat emboli?

Answer 26

Hypoxemia, neurologic abnormalities, petechial rash

Question 27

Multifocal ischemic necrosis of bone

Answer 27

Caisson disease, chronic form of air emboli.

Question 28

What are Charcot-Leyden crystals?

Answer 28

Eosinophilic, hexagonal, double-pointed, need-like crystals form from breakdown of eosinophils in sputum, associated with asthma

Question 29

What are Curschmann spirals?

Answer 29

Shed epithelium forms whorled mucus plugs (associated with asthma)

Question 30

What is bronchiectasis?

Answer 30

Chronic necrotizing infection of bronchi causes permanently dilated airways, purulent sputum, recurrent infections, hemoptysis

Question 31

Which drugs can cause interstitial lung diseases?

Answer 31

Bleomycin, amiodarone, methotrexate, busulfan

Question 32

What do you see in hypersensitivity pneumonitis

Answer 32

Mixed type III/IV hypersensitivity, predominance of CD8+ cells, often seen in farmers and those exposed to birds

Question 33

What is Caplan syndrome?

Answer 33

Rheumatoid arthritis and pneumoconioses with intrapulmonary nodules

Question 34

What is anthracosis

Answer 34

Asymptomatic condition found in many urban dwellers exposed to sooty air

Question 35

"Eggshell" calcification of hillier lymph nodes

Answer 35

Silicosis

Question 36

What do you see on histology in silicosis

Answer 36

Birefringent silica particles surrounded by fibrous tissue

Question 37

What is silicosis associated with?

Answer 37

Foundries, sandlasting, mine

Question 38

What is the relationship between silicosis and TB

Answer 38

Silica may disrupt phagolysosomes and impair macrophages, increasing susceptibility to TB

Question 39

What does therapeutic O2 in neonates predispose to?

Answer 39

Retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia

Question 40

What is idiopathic PAH often due to?

Answer 40

An inactivating mutation in BMPR2 gene (which normally inhibits vascular smooth muscle proliferation)

Question 41

What are Light's criteria:

Answer 41

Exudate if 2 of 3: Effusion protein/serum protein ratio >0.5, effusion LDH/serum LDH >0.6; Effusion LDH > 2/3 the upper limit of the reference range

Question 42

What are lung abscesses often caused by?

Answer 42

Anaerobes (eg. Bacteroides, Fusoacterium, Peptostreptococcus) or S. pneumo

Question 43

"Cough productive of foul-smelling sputum"

Answer 43

Abscess

Question 44

Tumor cells with long, slender microvilli and abundant tonofilaments

Answer 44

Mesothelioma

Question 45

What is the immunohistochemical marker for mesothelioma

Answer 45

Pancytokeratin

Question 46

Where does lung cancer metastasize to?

Answer 46

Adrenals, brain, bone (pathologic fracture), liver (jaundice, hepatomegaly)

Question 47

Tx of small cell lung cancer

Answer 47

Chemotherapy (Inoperable!!)

Question 48

Lung cancer that's chromogranin A +

Answer 48

Small cell or bronchial carcinoid tumor

Question 49

What does small cell carcinoma stain positive for?

Answer 49

Chromogranin A, neural cell adhesion molecule (NCAM), neuron-specific enolase, and synpatophysis

Question 50

What does CXR show in bronchioloalverolar subtype of adenocarcinoma of the lung?

Answer 50

Hazy infiltrates similar to pneumonia because it grows along alveolar septa causing apparent "thickening" of the walls. This type has an excellent prognosis.

Question 51

Which type of lung tumor can secrete beta-HCG?

Answer 51

Large cell carcinoma. Also has pleomorphic giant cells and a poor prognosis.

Question 52

What is chlorpheniramine

Answer 52

First generation H1 blocker

Question 53

What is hydroxyzine

Answer 53

First generation H1 blocker

Question 54

What is loratadine

Answer 54

Second generation H1 blocker

Question 55

What is fexofenadine

Answer 55

2nd gen H1 blocker

Question 56

What is desloratadina

Answer 56

2nd gen H1 blocker

Question 57

What is dimenhydrinate

Answer 57

1st gen H1 blocker

Question 58

MOA of N-acetylcysteine for expectoration

Answer 58

Loosens mucus plugs by disrupting disulfide bonds

Question 59

MOA of dextromethorphan

Answer 59

Antagonizes NMDA glutamate receptors. Synthetic codeine analog

Question 60

MOA of bosentan

Answer 60

Endothelia receptor antagonist to decrease pulmonary vascular resistance. Hepatotoxic (monitor LFTs)

Question 61

What can PDE5 inhibitors be used for other than erectile dysfunction

Answer 61

Pulmonary HTN

Question 62

MOA of epoprostenol, iloprost

Answer 62

Prostacyclin (PGI2) analogs with direct vasodilatory effects on pulmonary and systemic arterial vascular beds. Inhibit platelet aggregation

Question 63

MOA of ipratropium

Answer 63

Muscarinic antagonist, competitively blocks muscarinic receptors, preventing bronchoconstriction

Question 64

MOA of montelukast and zafirlukast

Answer 64

Block leukotriene receptors (CysLT1).

Question 65

What are montelukast and zafirlukast especially good for?

Answer 65

Aspirin-induced asthma

Question 66

MOA of zileuton

Answer 66

5-lipoxygenase pathway inhibitor. Blocks conversion of arachidonic acid to leukotrienes. Hepatotoxic

Question 67

What is omalizumab?

Answer 67

Monoclonal anti-IgE antibody. Binds mostly unbound serum IgE and blocks binding to Fc-epsilon-RI. Used in allergic asthma resistant to inhaled steroids and long-acting beta2-agonists

Question 68

What type of drug is theophylline?

Answer 68

Methylxanthine

Question 69

MOA of theophylline

Answer 69

Likely causes bronchodilation by inhibiting phosphodiesterase causing increased cAMP levels due to decreased cAMP hydrolysis. Also blocks actions of adenosine (which cause bronchoconstriction)

Question 70

Toxicity of theophylline

Answer 70

Seizures and tachyarrhythmias

Question 71

MOA of methacholine

Answer 71

Muscarinic receptor (M3) agonist.

Question 72

MOA of magnesium in an acute asthma flare-up

Answer 72

Inhibits Ca influx into airway smooth muscle