nbme 13 qs

[sadaca]

A 62-year-old man is brought to the emergency department because of a 3-hour history of progressive difficulty breathing and mild left shoulder pain. His symptoms began after he ran up several flights of stairs. He has poorly controlled hypertension and mild angina pectoris. He has smoked one-half pack of cigarettes daily for 40 years. He appears uncomortable and has labored breathing. Diffuse crackles, ronchi, and scattered wheezing on auscultation of the posterior lung fields. His arterial PO2 is 58 mm Hg. Which of the following is the most likely diagnosis?
A. Cardiac tamponade
B. Pneumonitis
C. Pneumothorax
D. Pulmonary edema
E. Pulmonary embolism

correct ans is D, could someone how to pick up on that please? I found the answer through other blogs but no explanation.
Did he have underlying HF, and the crackles and wheezing gives it away? Thank you

1. 42 yr woman comes to the physician because of 3 weeks history of numbness of the fingers on the left hand. Neuro exam shows loss of touch graphesthesia and loss of two-point discrimination in the left hand. Lesion location is?? Its picture of a brain with letters , I can't post it on here but does anyone remember this question? Or if anyidea on what condition this is, it can help.

Thanks aALOT

---

Members don't see this ad.

 

[alicealicealice]

1) That is a classic CHF presentation.
Demographic: Old, male HTN, smoking, pre-existing angina = prime candidate for ischemic cardiomyopathy and/or hypertensive cardiomyopathy
Symptom: Dyspnea on exertion (they could also throw in orthopnea and paroxysmal nocturnal dyspnea, lower extremity edema)
Signs: Bibasilar crackles, leading to hypoxia (PO2 58 = SaO2 ~ 90%) secondary to shunting from pulmonary edema (they could add an S3 or S4 on cardiac exam)
Furthermore, the other choices don't make sense.
Too stable for tamponade.
Pneumothorax causes absence breath sounds hyperresonance to percussion and tracheal deviation (towards lesion if spontaneous, away from lesion if tension), not crackles. Also changes would not be diffuse or bilateral.
PE does not affect the lung exam, certainly not with bilateral crackles, in addition to incompatible history.
Pneumonitis requires some infectious or allergic exposure or aspirate which is not present in the vignette.

2) IIRC, if it was a picture of a brain and not a spinal cord section, then maybe contralateral (i.e. R) parietal lobe?

 

[Fatalis]

The give away for the 1st question is the P02; it is less than a normal value. This implies that 02 is having a hard time getting to his tissues.
A- they would give you more sx such as distended veins, pulsus paradoxus, etc
B- maybe they would have given you the patient with fever/ recent infection,etc
C- air in the lungs; you would not hearing crackles/wheezing, you would hear decr breath sounds and percussion would show hyperres.
D- this seems plausbile as edema would decr the amount of 02 reaching the alv; Fi02 and PA02 would be normal but the barrier btwn PA02 and Pa02 is thicker
For the 2nd question; think about the dorsal column tract=> postcentral gyrus=> homonoculus (spelling) and that should give you an idea; I havent seen the question but it is just a hunch on what they are asking.

 

[sadaca]

hey guys, thank u SO SO much. you're explanations were so helpful. I see where I went wrong now .

 

[sadaca]

Hey guys, so I was wondering why the pO2 is less in HF ? Is it when LHF causes pul edema ? Thats what threw me off b/c I saw low PO2 and thought PE . Also, HF underlying HTN and MI are causes , is that right? Thanks alot I mix up cardio and resp, trying to keep them separate.

also, for the 2nd question Do u think it fits the case for Gerstmann syndrome? @ FATALIS - how did you come up with postcentral gyrus by seeing dorsal col tract defects..Thanks SO much