2021-10-28-adrenal-disorders.md (2298B)
1 # Adrenal disorders 2 3 Dr Mona Mashayekhi MD, PhD 4 5 --- 6 7 ## Overview of adrenal insufficiency 8 9 | | ACTH | Cortisol | Aldosterone | Renin | DHEA | Na | K | ACTH stim | 10 |----------|------|----------|-------------|-------|------------|--------|-----|-------------| 11 | Primary | high | low | low | high | low | low |high | nonreactive | 12 | Central | low | low | wnl | wnl | low-normal*| low** | wnl | reactive $ | 13 14 15 \* DHEA has some response to ACTH 16 17 \*\* via DDAVP, less extreme hypoNa compared to primary 18 19 $ if longstanding central process, ACTH stim will *not* be normal d/t atrophy 20 21 Sheehan - ACTH zero, cortisol zero, ACTH stim will be normal (no time yet for atrophy) 22 23 24 ## Primary adrenal insufficiency 25 26 post-op, infx, hemorrhage, mets, autoimmune 27 28 More electrolyte abnormalities d/t aldosterone problems (ENAC -> K up, Na down, also some vessel tonicity -> HoTN) 29 30 ## Secondary adrenal insufficiency (central) 31 32 E.g. chronic steroids (causes 1, 2, 3 of AI are iatrogenic d/t steroid use), Sheehans 33 34 ACTH cleaved to POMC, melanocortin -> hyperpigmentation (palms more specific) 35 36 ### Primary AI tx 37 38 Prefer hydrocortisone, 39 as has short half-life and allows closer mimicry of physiologic levels. 40 Higher AM dose, lower PM dose. 41 42 Relative half-lives and physiologic doses of steroids: 43 44 | | dose | t 1/2 | 45 |-------|-------------|-------| 46 | dex | 0.25mg | +++ | 47 | pred | 4mg | ++ | 48 | hydro | ? | + | 49 50 51 --- 52 53 54 ## Primary hyperaldosteronism 55 56 Common, should suspect if low K and resistant HTN. 57 58 Many BP meds modulate HPA axis in some way or another, 59 practically only MRAs are considered sufficiently problematic to interfere with standard testing. 60 61 Start with aldo/renin ratio. 62 63 ### Primary hyperaldosteronism tx 64 65 Primary therapy is surgical. 66 67 MRA therapy can be helpful, 68 but does not prevent other effect of unopposed aldosterone (e.g. cardiac), 69 so preferred when pts are not surgical candidates. 70 71 For maximum effectiveness, titrate MRA dose to level of renin. 72 73 Adrenal venous sampling (AVS) - done by interventional radiology, highly specialized even within IR. 74 75 So some places, if <40yo, will just use CT evidence of nodule to justify removal. 76 (if >40yo, high likelihood of benign adenoma)