Pulm Flashcards
Structures cross the diaphragm at what levels
I ate 10 eggs at 12
- IVC - T8
- esophagus - T10
- aorta - T12
physiologic dead space equation
Vd = Vt x (PaCO2 - PeCO2)/PaCO2
taco, paco peco, paco
= tidal volume (arterial PCO2 - expired air PCO2)/arterial PCO2
things that favor the taught form of Hgb
Cl-, H+, CO2, 2,3BPG and temperature
- right shift favored by BAT ACE: BPG, altitude, temp, acid, CO2, exercise
methemoblobin
- oxidized Hgb (Fe3+), doesnt bind Hgb as well, seen in newborns and with oxidative stress (cyanosis and chocolate covered blood)
- binds cyanide well, so give nitrites to form methemoglobin in cyanide poisoning, then give thiosulfate to bind cyanide and be renally excreted
carboxyhemoglobin
CO binds Hgb, causes a left shift and pts have cherry red skin
perfusion limited vs. diffusion limited
- perfusion limited: things that are perfusion limited equilibrate early: O2 in healthy ppl, CO2, N2O
- diffusion limited: things that do not equilibrate by the time the blood reaches the end of the capillary: O2 in emphysema and fibrosis, CO
hypoxemia with normal Aa gradient
high alt, hypoventilation
hypoxemia with increased Aa gradient
VQ mismatch, diffusion limitation, RL shunt
V/Q = 0
shunt
- does not improve with 100% O2
V/Q = infinity
blood flow obstruction
- does improve with 100% O2
Haldane effect
oxygenation of Hgb promotes dissociation of H+ from Hgb, therefore CO2 is released
Bohr effect
increased H+ in the tissue causes a right shift, causing unloading of O2
response to high altitude
decreased PaO2 leads to hyperventilation
- increased EPO
- increased 2,3BPG for more O2 unloading
- more renal excretion of bicarb to compensate for respiratory alkalosis
response to exercise
increased CO2 production and O2 consumption
- increased ventilation rate, and V/Q becomes more uniform throughout the lung
- no change in PaO2 and PaCO2, but increase in venous CO2 and decrease in venous O2 content
rhinosinusitis bugs
S. pneumo, H flu, M catarrhalis
virchow triad
- predisposition to DVTs
- stasis, hypercoagulability, endothelial damage
different types of emboli and their classic findings
- fat: hypoxemia, neurologic abnormalities and petechial rash
- amniotic fluid: DIC
- gas: divers, treat with hyperbaric O2
centriacinar vs. paracinar emphysema
- centri - smokers
- para - alpha 1 antitrypsin
asthma path findings
Curschman spirals (shed epithelium forms mucus plugs) Charcot-Leyden crystals (formed from breakdown of eosinophils in sputum)
bronchiectasis
- chronic necrotizing infection of bronchi –> permanently dilated airways, purulent sputum, recurrent infections and hemoptysis
- assoc w/ bronchial obstruction, poor ciliary motility (smoking), Kartagener syndrome, CF, allergic bronchopulmonary aspergillosis
asbestosis findings and increased risks
- asbestos (ferrunginous) bodies are golden-brown fusiform rods resembling dumbells
- increased incidence of bronchogenic carcinoma and mesothelioma
silicosis findings
- impairs macrophages, leads to fibrosis and increased susceptibility to TB
- “eggshell” calcification of hilar lymph nodes
pulm HTN
- primary due to BMPR2 gene, leading to vascular smooth muscle cell proliferation, poor prognosis
- secondary due to COPD, VTE, AI disease, L-R shunt, sleep apnea or high alt
most common sites that metastasize TO the lungs
breast, colon, prostate, bladder
most common sites that the lungs metastasize to
adrenals, brain, bone, liver
lung adenocarcinoma
- most common
- peripheral
- activating mutations include k-ras, EGFR, and ALK
- clubbing
squamous cell carcinoma of the lung
- Central, Cavitation, Cigarrettes, hyperCalcemia (PTHrP)
- SCa+++mous
- keratin pearls and intercellular bridges
small cell (oat cell) lung cancer
- central, undifferentiated, aggressive
- Acth, Adh, Antibodies (Lambert-Eaton), Amplification of myc
- inoperable, treat with chemo
- neoplasm of the neuroendocrine Kulchitsky cells –> small dark blue cells
large cell carcinoma
- peripheral
- highly anaplastic undiff tumor, poor prognosis
- removed surgically
- pleomorphic giant cells
bronchial carcinoid tumor
- excellent prognosis
- symptoms due to mass effect, occasionally carcinoid syndrome (flushing, diarrhea, wheezing)
- nests of neuroendocrine cells, Chromagranin A +ve
mesothelioma
- malignancy of the pleura with hemorrhagic pleural effusions and pleural thickening
- psammoma bodies
pancoast tumor
- Horner, SVC, sensorimotor defects, hoarseness, upper extrem edema
transudate pleural effusion
low prot content
- CHF, nephrotic syndrome, hepatic cirrhosis
exudate pleura effusion
high prot content
- malignancy, infection, collagen vascular disease, trauma
lymphatic pleural effusion
- milky fluid with high TG
- thoracic duct injury
1st gen H1 blockers
- diphenhydramine, dimenhydrinate, chlorpheniramine
- used in allergy, motion sickness, sleep aid
- tox - sedation, antimuscarinic, anti-adrenergic
2nd gen H1 blockers
- loratidine, fexodenadine, desloratidine, cetirizine
- used in allergy
- tox - less sedating because less CNS penetration
guaifenesin
expectorant - thins resp secretions, does not suppress cough reflex
NAC
mucolytic - can loosen mucous plugs in CF kids
dextromothorphan
- antitussive (NMDA antagonism)
- synthetic codeine analog
- mild opioid effect in excess, mild abuse potential
- naloxone can be given for overdose
pseudoephedrine, phenylephrine
- alpha agonist nasal decongestants
- reduce hyperemia, edema and nasal congestion
- tox - HTN, can also cause CNS stimulation/anxiety
- tachyphylaxis - rapidly declining effect after a few days due to decreased production of norepi at nerve terminals
b2 agonists
- albuterol (short), salmeterol, formoterol (long-acting)
- relaexes smooth muscle
- SE: tremor and arrhythmia
theophylline
- methylxanthine that causes bronchodilation by inhibiting PDE –> inc CAMP because of decreased breakdown
- narrow TI, p450 metabolizes it, blocks adenosine actions
beclomethasone, fluticasone
corticosteroids that inactivate NFkB, the transcription factor that induces the production of TNFa and other inflammatory cytokines
monteleukast, zafirlukast
leukotriene receptor blocker, good for aspirin-induced asthma
zileuton
5-lipoxegenase pathway inhibitor (blocks AA –> leukotriene conversion)
omalizumab
monoclonal IgE Ab for allergic asthma
bosentan
used to treat pulmonary arterial hypertension, competitively antagonizes endothelin-1 receptors, decreased pulmonary vascular resistance
