NBME Answers : rolubui's page

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+10 visit this page (nbme24#26)

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1) Alcohol withdrawal --> seizure

2) Seizure --> increased release of catecholamines (https://www.ncbi.nlm.nih.gov/pubmed/6538024), also BP of 180/100 indicates high levels of catecholamines

3) Major hormones that shift K+ intracellularly are insulin & beta-2-adrenergic agonists (e.g. epinephrine (http://www.clinicalguidelines.scot.nhs.uk/media/1286/fig1picu007.png)

4) Also they are asking why serum K+ is low, NOT why urine K+ is high

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osler_weber_rendu Point 4) above helps you RULE OUT MUSCLE BREAKDOWN. It will cause initial hyperkalemia. Hypokalemia, if at all happens weeks later in ATN. +3

hungrybox Thanks for explaining why it's not muscle breakdown. Was stuck on that one. +

+3 visit this page (nbme23#14)

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The way I remember it, S1: Mitral & tricuspid bc blood goes from atria to ventricles then from ventricles to outside the heart --> S2. Now, when you have a Split S1 the way I think about is that when you inhale you have extra blood coming into the right side of the heart so the tricuspid valves closes later and causes a split S1 upon respiration. Hope that helps.

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submitted by drmohandes(193), visit this page

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SIADH → euvolemic hyponatremia → normotensive / hypertensive
ACTH increases cortisol → hypertension (alpha-1 upregulation & cortisol can bind to aldosteron receptors at high concentrations)
ACTH increases aldosterone → hypertension + hypokalemia (K+ dumped in collecting duct)

If patient -only- had hypertension: ACTH more likely than SIADH.

Patient with hypertension AND hypokalemia: 100% ACTH.

Don't feel bad friends, I also had this question wrong :(...

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rolubui ACTH does NOT act directly on the zona glomerulosa to increase Aldosterone. ACTH acts only on the zona fasciculata to increase cholesterol and zona reticulata to increases sex hormones. +4

rolubui NOT cholesterol I mean cortisol in zona glomerulosa +

jurrutia Yes, but cortisol can act as a mineralocorticoid at when levels are super high. +

an1 @rolubui absolutely agreed! UW has a question where they ask about the precuor of aldosterone. I chose ACTH. WRONG they said, it's angiotensin 2. And yet these NBME writes are saying that ACTH is responsible for both cortisol and aldosterone? no. +

submitted by drmohandes(193), visit this page

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SIADH → euvolemic hyponatremia → normotensive / hypertensive
ACTH increases cortisol → hypertension (alpha-1 upregulation & cortisol can bind to aldosteron receptors at high concentrations)
ACTH increases aldosterone → hypertension + hypokalemia (K+ dumped in collecting duct)

If patient -only- had hypertension: ACTH more likely than SIADH.

Patient with hypertension AND hypokalemia: 100% ACTH.

Don't feel bad friends, I also had this question wrong :(...

get full access to all content ⋅ become a member

rolubui ACTH does NOT act directly on the zona glomerulosa to increase Aldosterone. ACTH acts only on the zona fasciculata to increase cholesterol and zona reticulata to increases sex hormones. +4

rolubui NOT cholesterol I mean cortisol in zona glomerulosa +

jurrutia Yes, but cortisol can act as a mineralocorticoid at when levels are super high. +