HY lecture notes:
32M + pneumothorax that does not resolve following placement of a chest tube; Dx? –> ruptured bronchus or rupture of intrathoracic trachea.
32M + pneumothorax with a persistent air leak despite chest tube placement; Dx? –> ruptured bronchus or rupture of intrathoracic trachea.
32M + contralateral tracheal deviation + low BP; Dx? –> tension pneumothorax; Tx = needle decompression followed by chest tube. If out in the field (i.e., not in hospital), if there is penetrating chest trauma, tape over the wound on three sides only, so air can exit but not enter. Tension pneumothorax need not be associated with penetrating chest trauma, but this is one of the most common etiologies.
Mechanism of low BP in tension pneumothorax? –> answer = compression of venous structures (IVC).
25M + tall +/- uses cocaine + has dyspnea + air in pleural space; mechanism? –> rupture of subapical bleb causing spontaneous pneumothorax; Tx = can technically observe if very small and patient stable; however answer on USMLE will still be needle decompression followed by chest tube.
35F + C-section 24-48 hours ago + crackles at both lung bases; Dx? –> atelectasis; normally the fever is within 24 hours, but a Q on one of the forms says “two days after surgery.”
48M + motor vehicle accident (MVA) + rib fractures + paradoxical breathing (i.e., chest wall moves outward with exhalation and inward with inhalation); Dx? –> flail chest.
48M + MVA + has severe pain and/or bruising over the sternum; Dx? –> myocardial contusion –> do an ECG + monitor in hospital due to high risk of arrhythmia. Get troponins.
This is where things get hard for the surg shelf:
48M + MVA + rib fractures + underlying infiltrates + no other info given in the stem; Dx? –> pulmonary contusion. The Q will not say “white-out of the lung” –> too easy / buzzwordy of a description.
48M + MVA + no rib fractures + lobar infiltrates + no other info given in the stem; Dx? –> pulmonary contusion –> need not have rib fractures for pulmonary contusion.
48M + MVA +/- rib fractures + O2 sats decrease when 2L of fluid is given; Dx? –> pulmonary contusion –> contused lung is very fluid sensitive.
48M + MVA +/- rib fractures + severe pain/bruising over the sternum + O2 sats decrease when 2L of fluid is given; Dx? –> myocardial contusion, not pulmonary contusion –> weird, because the stem said the O2 sats decreased with fluid, but the pain/bruising over the sternum “wins.”
Pulmonary contusion isn’t a diagnosis of exclusion per se, but I’ve noticed across NBME Qs that the presentation is fairly non-specific.
Essentially:
Is there paradoxical breathing? Yes? Ok, flail chest. No? Ok, not flail chest.
Do they mention a persistent air leak despite a chest tube? Yes? Ok, ruptured bronchus. No? Ok, not ruptured bronchus.
Do they say bruising/pain over the sternum? Yes, Ok, myocardial contusion. No? Ok, not myocardial contusion.
Do they say pulmonary infiltrates on CXR in the setting of trauma and I’ve eliminated the above three Dx? Yes? Ok, pulmonary contusion is likely answer.
