Mehlman Idiopathic pulmonary fibrosis (10-29) (2)

Question 1

Q. Patient over the age of 50 who has 6-12+ months of unexplained dry cough. This is how it shows up 4/5 times.
Dx?

Answer 1

Idiopathic pulmonary fibrosis

Question 2

Type of lung disease? PFT

Answer 2

restrictive
normal ir incr FEV1/FVC

Question 3

Why normal ir incr FEV1/FVC?

Answer 3

The reason for the FEV1/FVC being greater than in obstructive lung disease is radial traction, as mentioned earlier.

Question 4

What shows xray or CT?

Answer 4

CXR and CT scan show “reticular” or “reticulonodular” pattern. AKA honeycomb.

These descriptors are exceedingly HY on USMLE/ highly buzzy words.

Question 5

After the CXR and spirometry are performed, 2CK wants what diagnostic (next best step)?

Answer 5

“high resolution CT of chest” as answer for next best step.

Question 6

After imaging, how to CONFIRM DIAGNOSIS?

Answer 6

New 2CK NBME wants “lung biopsy” as answer to confirm diagnosis of
interstitial lung disease (i.e., idiopathic pulmonary fibrosis) after imaging.

Question 7

1/10 times, the Q will be patient over 50 with increasing fatigue and SOB over 6-12 months, with only 1 month of cough,
where it initially sounds like heart failure, and they’ll say CXR shows “interstitial markings” instead of reticular/reticulonodular patterning.

Answer 7

However, they say patient has “­ FEV1/FVC showing restrictive pattern” in the stem, which gives it away

Question 8

another name for idiopathic pulmonary fibrosis?

Answer 8

“usual interstitial pneumonitis” (UIP)

Question 9

Tx????

Answer 9

Tx on 2CK = pirfenidone

It’s anti-fibrotic agent that inhibits TGF beta mediated synthesis of collagen

Question 10

what crackle and murmur?

Answer 10

Vignette can also mention loud P2 (means pulmonary hypertension) with “dry inspiratory crackles heard bilaterally.”

Question 11

Restrictive lung disease. Normal or increased FEV1/FVC.

What changes those variables as
,,independent”?

Answer 11

FEV1 and FVC are both, as independent variables, decreased. But the ratio is normal or increased.

There’s a Q on a newer NBME for Step 1 that forces you into a corner to choose normal FEV1 as an independent variable, but it was the only answer that made sense. So just be aware it’s never hard-and-fast rule for the variables.

Question 12

Restrictive.
Radial traction?

Answer 12

Radial traction in restrictive lung disease = “stickiness” of fibrosis on the outside of the airways, decreasing their ability to close –> FEV1 is greater than expected –> FEV1/FVC is greater than expected. In contrast, obstructive lung disease the ratio is decreased because radial traction isn’t involved.