Flashcards in 5 Nephrology and Acid-Base Deck (36):
-granular/muddy brown casts
-granular/muddy brown casts--ATN
-WBC casts--AIN, pyelo
3. 30-60 complications start appearing, tx them
4. 15-30 prepare dialysis (get AV fistula now so it can heal)/transplant
5. <15. ESRD, dialysis required
overload (CHF, edema)
ATN: think what 3 main causes
prolonged ischemia, drugs/toxins, and contrast
-how long take to recover, what tx
1. prodrome: increased Cr
2. oliguric: UOP deceased (fluid overload!)
3. polyuric: UOP increased (diuresis!)
2-3 weeks for tubular cells to regenerate. Do supportive dialysis to prevent life-threatening e-lyte imbalances.
kidneys think they're dehydrated, will hold on to salt.
UNa<10, FENa <1% (tubular fxn intact)
Urine osmols >500 (can still concentrate)
FE Urea<35%. Use FE Urea if on diuretic
kidney is broken; can't reabsorb Na or concentrate urine.
Pt with renal damage, but needs contrast for imaging. Do what? (3 things)
prevent contrast-induced ATN.
1. vigorous hydration
3. stop diuretics and ACE/ARBs
Pt gets ARF, with increased Cr.
What labs to get first?
First, r/o prerenal:
FE Urea if diuretics
Renal Failure, my mnemonic
MR CA PUNK
Met acid, renal osteodystrophy
HypoCa (from low VitD and 2ndary hyperPTH), Anemia (low EPO)
Hyperphosphatemia, Uremia, increased Na, hyperkalemia
-HTN and DM treatment goals.
-what to be aware of in DM
HTN: strict <130/80
DM: A1C<7, same.
In DM, must use oral meds. NOT metformin, NOT insulin. Metformin causes lactic acidosis. Insulin cleared by kidneys, so beware of hypoglycemia with insulin retention
what are the 2 stages
early stage: BUN 'forced' back into blood by pressure. BUN/Cr>15.
Tubular fxn intact, so FENa<1%, urine osmol>500
(same numbers as Prerenal)
late stage: Tubular damage, so:
urine osmol <500
Intrarenal ARF: think what main 3 causes? look for what on microscopy? and main causes for each?
1. ATN (muddy casts).
prolonged ischemia, toxins/drugs, contrast
2. AIN (WBC casts from inflamm).
drug hypersensitivity (eg NSAIDs), pyelo, infiltrative dz (amyloid, sarcoid)
3. GN (RBC casts)
Pt with acute leukemia. You treat with chemo. What to be aware of with kidneys and what to do?
beware tumor lysis syndrome leading to ATN from high uric acid.
Give hydration and allopurinol (decrease formation of uric acid)
side effect of EPO in ESRD
contrast induced ATN. when after use does it occur?
ARF 7-10 days post procedure
general approach and decision points
1. Serum osmols. If low <280, then true hypotonic hypoNa. Otherwise, pseudo.
2. Volume status
-overload: CHF, nephrosis, cirrhosis
-normal volume: "RATS"
RTA, Addison's, Thyroid, SIADH
-hypovolemia. give IVF
prerenal vs intrarenal
How to corrent Na and Ca
Na: every 100 over 100, add 1.6
Ca: every 1 albumin <4, decrease Ca by 0.8
HyperCa sxs. what are they really
"bones, stones, groans, psychiatric overtones"
-N/V, abd pain
-AMS, only at 13-15 severe
hungry bone syndrome
after parathyroid adenoma removal, the remaining glands take time to rev back up. So temporary hypoCa
HyperCa of malignancy. mechs?
Also, sarcoid mech
1. mets to bone
2. PTH-rp (Squamous cell carcinoma)
3. increase in 1,25 VitD
Young pt hospitalized after MVC trauma. Now has hyperCa, think what
HyperCa of immobilization. Get them walking and out of bed
Young pt with asx hyperCa and positive family hx. Think what?
FHH: Familial hypocalciuric hypercalcemia
-Bad Ca sensor at parathyroid, so secrete more PTH anyway. No tx
2. CKD, starting with low VitD leading to low Ca, stimulating PTH. So, Ca usu low/normal.
3. CKD/ESRD, autonomous adenomas.
hyperCa of malignancy form bone breakdown, Tx
Vigorous hydration, alendronate. Lasix probably not, lost favor.
HyperK sxs (3) other than EKG change
-in real life, what 2 main groups of causes to think of
-on test, what causes to think of: (3)
1. GI losses (diarrhea, vomiting)
2. Renal losses (diuretics)
1. Bartter syndrome (Lasix)
-how to replace K+, what rates?
-how fast do you want K to increase
-if K is not increasing, think what?
PO is best.
1. PIV: <10 meq/h because K+ burns in peripheral
2. Central: <20 meq/h because fear of arrythmia
Gen rule: 10 mEq increases K by 0.1. increasing K by 0.1/hour is ideal.
-Check Mg. replace that
kidney stones: what is medical expulsion therapy
when to use
CCB and alpha blockers
Can use if <7mm
Struvite stone classic story
Elderly pt with frequent UTIs. UA shows hematuria, no pyuria, and ALKALINE urine
kidney Stone sizes to know
<5mm IVF and analgesia
<7mm can use MET
>30mm surgery for sure
In between: depends, lithotripsy, uretoscopy, etc
-think what 3 extrarenal things
So, SAH, cirrhosis, pancreatitis
Renal cyst, big picture approach?
Ask yourself, is this RCC??
1. if cyst small, think simple, no tx
2. if cyst big with septations, think complex cyst, do needle bx
3. If classic triad, or paraneoplastic sxs (anemia or polycythemia), think RCC. Do CT. Then Cut it out, no bx
Predicted anion gap
Albumin x3. So, with alb 4, AG predicted is 12
Alb 2, predicted is 6.
-how to approach dx
1. volume responsive?
Measure Urine Cl. If low (<10), then contraction alk (high aldo retaining NaCl, so Cl low). Give fluids
If Urine Cl >10, not volume responsive.
-urine Cl>10 and HTN, then hyperaldosteronism (not responsive to fluids). eg RAS and Conn's syndrome
-urine Cl>10 and no HTN, then think genetic. Bartter and Gitelman