Mehlman pneumothorax (10-28) (2)

Question 1

Definition?

Answer 1

Air in the pleural space.

Question 2

pneumothorax CP and in what patients?

Answer 2

The terms almost always refers to a “spontaneous pneumothorax,” which will be acute-onset sharp chest pain in a tall, lanky patient in teens or 20s due to “ruptured subapical bleb.”

Question 3

tension pneumothorax CP?2

Answer 3

Pneumothorax + low BP

Question 4

Pneumothorax + low BP =?

Answer 4

tension pneumothorax

Question 5

mechanism of tension pneumothorax?

Answer 5

Mechanism for tension pneumothorax is compression of the vena cavas leading
to decr. venous return –> can cause JVD.

Question 6

what tracheal shift in simple/spontaneous?

Answer 6

ipsilateral tracheal shift.

Question 7

what tracheal shift in tension?

Answer 7

contralateral tracheal shift.

Question 8

Tension pneumothorax need not be due to overt trauma. It will literally just be pneumothorax + low BP 9/10 times on USMLE.

I’ve seen only one Q on a 2CK form where BP is lower end of normal, but the patient is tachy around 120 bpm
(implying barely holding BP in normal range).

Answer 8

.

Question 9

percussion, breath sound and tactile fremitus?

Answer 9

Patient will have hyperresonance to percussion, decr. breath sounds, and decr. tactile fremitus

Question 10

why decr. breath sounds?

Answer 10

Breath sounds are decr. because the air in the pleural space masks the sounds of underlying air flow in the alveoli.

Question 11

why decr. tactile fremitus?

Answer 11

Tactile fremitus is decr. because the vibration of air in the alveoli is masked by the overlying air

Question 12

One 2CK Q just has “tube thoracostomy” as the answer without needle decompression being listed. So if they don’t list the needle, don’t be confused, and just choose the chest tube. Thoracostomy means making a hole in the thorax.

Answer 12

.

Question 12

Treatment for pneumothorax??? HY sequence

Answer 12

needle decompression followed by chest tube

Question 13

Pleurodesis I’ve never seen as correct answer on NBME material but can be listed as distractor. Means putting talc into pleural space to obliterate it in patients who have recurrent pneumothoraces.

Answer 13

.

Question 14

very small pneumothoraces in stable patients with minimal
symptoms, Tx?

Answer 14

can be observed.

There is one Q on a 2CK NBME form where the answer is observe. But the vignette goes out of its way to emphasize how unremarkable the patient’s presentation is.

Question 15

There is a 2CK Q where pneumothorax is caused by barotrauma from ascending
too quickly from underwater. This is different from Caisson disease (“the bends”), where nitrogen bubbles form in the blood. Pulmonary barotrauma from quick ascent, resulting in pneumothorax, can occur if some of the alveoli expand too
quickly.

Answer 15

.