Mehlman alveolar conditions (10-29) (2)

Question 1

Pulmonary edema. cause on usmle?

Answer 1

left heart failure

Question 2

Pulmonary edema.
,,non-cardiac” causes?

Answer 2

(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.

Question 3

Pulmonary edema. PCWP and LAP?

Answer 3

both elevated

Question 4

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 =?

Answer 4

“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

Question 5

Pulmonary edema. what buzzy words?

Answer 5

Cephalization of pulmonary vessels” is buzzy and synonymous with
pulmonary edema on USMLE. Shows up in some NBME vignettes.

Question 6

ARDS.
bilateral exudative chest infiltrates and decr. O2 sats
in patient with what conditions?

Answer 6

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.

Question 7

2CK NBME Q gives vignette of toxic shock syndrome and then asks most
likely cause of death in this patient -> answer =?

Answer 7

ARDS

Question 8

ARDS. very buzzy definition?

Answer 8

Pulmonary decompensation associated with pancreatitis

Question 9

Another 2CK Q gives patient who is brought to hospital following near drowning episode + they ask what the patient needs to be monitored for?

Answer 9

ARDS

Question 10

ARDS. what PaO2/FiO2 defines ARDS?

Answer 10

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.

Question 11

ARDS.
I emphasize up above the bilateral nature of ARDS because many Qs give ARDS as DDx for unilateral conditions and it’s wrong.

Answer 11

.

Question 12

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

Answer 12

.

Question 13

ARDS. Patient recovering from ARDS, what increases?

Answer 13

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.

Question 14

TRALI. definition?

Answer 14

If a patient has an ARDS-like presentation with bilateral crackles and low O2 sats <6 hours following a transfusion.

Question 15

if a patient has an ARDS-like presentation with
bilateral crackles and low O2 sats <6 hours following a transfusion.?

Answer 15

TRALI.

Question 16

TRALI. mechanism?

Answer 16

Mechanism is abnormal priming of neutrophils in the lung that react to cytokines within transfused blood products

Question 17

TRALI. what type of pulmonary edema?

Answer 17

This is technically a type of non cardiogenic pulmonary edema.

Question 18

TACO = Transfusion-associated circulatory overload

Answer 18

.

Question 19

TACO. aka?

Answer 19

transfusion-induced hypervolemia.

Question 20

TACO. how differs from TRALI?

Answer 20

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).

Question 21

TACO. annoying diagnosis. presents 2 ways.

Answer 21

.

Question 22

TACO. 1st. case.
Hx of heart failure/MI + develops respiratory distress following tranfusion of repeated blood products.

Answer 22

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).

Question 23

TACO. 2nd case.

They don’t mention Hx of cardiovascular disease + the vignette will sound exactly like TRALI > 6 hours following a transfusion.

Answer 23

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

Question 24

TACO. Clinical presentation -> next best diagnosis?

Answer 24

chest x ray

Question 25

In summary, if ARDS-like picture after transfusion:

If <6 hours?

Answer 25

TRALI

Question 26

In summary, if ARDS-like picture after transfusion:

If >6 hours?

Answer 26

TACO

Question 27

In summary, if ARDS-like picture after transfusion:

If heart disease?

Answer 27

TACO regardless of time frame.