Mehlman alveolar conditions 03-11 (3) Flashcards
Pulmonary edema. cause on usmle?
left heart failure
Pulmonary edema.
,,non-cardiac” causes?
(i.e., ARDS, TRALI)
If you seen “pulmonary edema” as an isolated phrase, it refers to transudation of fluid into the alveolar spaces due to pulmonary capillary hydrostatic pressure
from left heart pathology.
Pulmonary edema. PCWP and LAP?
both elevated
Pulmonary edema.
USMLE can give you vignette of, e.g., MI with dyspnea, and they ask for the
mechanism of the dyspnea in the patient -> answer =?
“increased alveolararteriolar oxygen gradient” – i.e., the patient can breathe just fine so alveolar O2 is normal, but fluid impairs the gas exchange, so we have low arterial/arteriolar oxygen
Pulmonary edema. what buzzy words?
Cephalization of pulmonary vessels” is buzzy and synonymous with
pulmonary edema on USMLE. Shows up in some NBME vignettes.
ARDS.
bilateral exudative chest infiltrates and decr. O2 sats
in patient with what conditions?
pancreatitis; aspiration of vomitus; near-drowning episodes (aspiration of fresh/sea water); improper insertion of NG tube into the lungs with feeding initiated; toxic shock syndrome; or general trauma /sepsis.
2CK NBME Q gives vignette of toxic shock syndrome and then asks most
likely cause of death in this patient -> answer =?
ARDS
ARDS. very buzzy definition?
Pulmonary decompensation associated with pancreatitis
Another 2CK Q gives patient who is brought to hospital following near drowning episode + they ask what the patient needs to be monitored for?
ARDS
ARDS. what PaO2/FiO2 defines ARDS?
ARDS is technically defined as a PaO2/FiO2 <300, but USMLE doesn’t give a
fuck. I’ve never once seen them apply this ratio or care.
ARDS.
I emphasize up above the bilateral nature of ARDS because many Qs give ARDS as DDx for unilateral conditions and it’s wrong.
.
ARDS.
In theory, patient can be ventilated as follows: prone positioning (patient on stomach) + low-tidal volume setting + permissive hypercapnia. IIRC this is asked once on a 2CK form
.
ARDS. Patient recovering from ARDS, what increases?
An offline NBME Q wants “increased surfactant protein D” as the answer in a
patient who is recovering from ARDS.
Apparently surfactant protein D is a marker of lung injury and is in patients with ARDS (or who are recovering
from it). Call it weird all you want but it’s on the NBME.
TRALI. definition?
If a patient has an ARDS-like presentation with bilateral crackles and low O2 sats <6 hours following a transfusion.
if a patient has an ARDS-like presentation with
bilateral crackles and low O2 sats <6 hours following a transfusion.?
TRALI.
TRALI. mechanism?
Mechanism is abnormal priming of neutrophils in the lung that react to cytokines within transfused blood products
TRALI. what type of pulmonary edema?
This is technically a type of non cardiogenic pulmonary edema.
TACO = Transfusion-associated circulatory overload
.
TACO. aka?
transfusion-induced hypervolemia.
TACO. how differs from TRALI?
this is a type of cardiogenic pulmonary edema (i.e., the left heart can’t handle the hydrostatic pressure from volume, so
transudation into the alveoli occurs).
TACO. annoying diagnosis. presents 2 ways.
.
TACO. 1st. case.
Hx of heart failure/MI + develops respiratory distress following tranfusion of repeated blood products.
A 2CK NBME Q gives a 72-yr-old with Hx of MI ten years ago who
gets shortness of breath and bilateral crackles 30 minutes after transfusion with crystalloid solution and 4 packs of RBCs (they don’t specify the volume of crystalloid in the Q).
TACO. 2nd case.
They don’t mention Hx of cardiovascular disease + the vignette will sound exactly like TRALI > 6 hours following a transfusion.
2CK form gives an elderly dude who received only 3 packs of RBCs + he develops bilateral crackles and low O2 sats, but they say this occurs 12 hours after admission (not <6 hours as with TRALI), where the answer is “X-ray of the chest” as the next best step in diagnosis.
The Q doesn’t rely on you discerning TACO vs TRALI to get it right, but the explanation says it’s TACO
TACO. Clinical presentation -> next best diagnosis?
chest x ray
In summary, if ARDS-like picture after transfusion:
If <6 hours?
TRALI
In summary, if ARDS-like picture after transfusion:
If >6 hours?
TACO
In summary, if ARDS-like picture after transfusion:
If heart disease?
TACO regardless of time frame.
