Flashcards in Renal Deck (58):
Causes of prerenal AKI
Pump: HF, MI
Leaky Vessels: Cirrhosis, nephrosis, gastrosis
Low volume: diarrhea, dehydration, diuresis, hemorrhage
Tubing issue: RAS, FMD
Causes of postrenal AKI
Obstruction leading to hydronephrosis
Bladder: Stones, cancer, neurogenic bladder
Urethra: Stones cancer, neurogenic, BPH, foley clog
Causes of renal AKI
Tubular issue (ATN)
Intertitial issue (AIN)
RBC casts on UA -- rule out nephrotic syndrome
>3.5mg protein, edema, increased cholesterol
Acute interstitial nephritis
Caused by drugs (beta lactams) or infection. WBC casts, eosinophils, rash, fever.
Acute tubular necrosis
Caused by ischemia, drugs/toxins (iv contrast, myoglobin, aminoglycosides). Brown muddy casts
Phases of intrarenal pathology
Prodrome with increased creatinine,
oliguric phase with decreased urine,
polyuric phase with increased urine.
How to calculate FeNa?
Clearance of Na/GFR
=Urine Na/Plasma Na * Plasma Cr/Urine Cr
Lab findings suggestive of prerenal pathology?
Stage II CKD and how to treat
GFR between 60 and 90
Aggressively treat comorbidities = BP
Stage III CKD and how to treat
Aggressively treat comorbidities
Stage IV CKD and how to treat
GFR 15-29. Put on transplant list, create AV fistula if symptomatic
Stage V CKD and how to treat
Indications for acute dialysis
Electrolyte abnormalities (hyper K)
Ingestion of toxins
How to decrease risk of contrast induced nephropathy?
IV NS, or use deiodinated contrast.
First step in working up hyponatremia?
Calculate vs measured serum osms
How to calculate S Osm?
Normal S osm?
How to correct Na if hypertonic hyponatremia?
For each 100 BG above 100, add 1.6 to Na.
Causes of euvolemic hyponatremia
Action of PTH
PTH maintains level of Ca in blood
Increased PTH activates osteoclasts to increse serum ca,
in kidney, PTH will resorb ca, excrete phos, and convert Vit D to active form to absorb more ca and phos.
Correction of ca for albumin
99% of calcium is albumin bound. Normal albumin is 4, if albumin reads 3, then need to add 0.8 to Ca.
Signs of hypocalcemia
Tetany, chvostek sign (tap facial nerve), trousseau's sign (bp cuff for 3 mins causes tetany), perioral tingling
How to work up hypocalcemia
Check albumin. If it corrects because albumin is low, then check ionized calcium level. If that's low, replete with IV calcium
Signs of hypercalcemia?
Stones, moans, bones, psychiatric overtones.
How to work up hypercalcemia?
Recheck calcium levels, if normal do nothing.
If high, then give IVF, then calcitonin.
Long term hyperca, give bisphosphonates.
Don't give loop diuretics because this has fallen out of favor.
Primary, secondary, tertiary hyperparathyroidism
Primary is autonomous PTH adenoma
Secondary is due to early renal failure
Tertiary hyperPTH is due to multple autonomous adenomas.
How does patient with hyperPTH present? Lab values?
Bone pain, pathologic fractures, brown tumors. Increased PTH, increased CA, decreased phos. Don't need vitamin D
How to determine 1 from 2 and 3 hyper PTH?
How to treat hyperparathyroidism
Resect and cinacalcet to prevent tertiary hyperparathyroidism
Hypercalcemia of malignancy
Cancer can cause hyperca from mets or from PTHrp.
Treat with bisphosphonates.
From granulomas. Increases Ca, decreases PTH, increases phos
Hyper Ca of immobilization
Causes Ca and phos to rise, and pth to decrease
Familial Hypercalcemic Hypocalciuria
Asymptomatic increase of calcium with decreased urinary calcium
Usually iatrogenic. Decreased PTH, Decreased Ca. Tx with IV Ca
Due to insensitivity to PTH.
Causes increased PTH, but decreased Ca.
Vitamin D deficiency.
Decreased Ca and phos, increased PTH, osteopenia.
Dx with 1,25oh D level
Tx with ca and vitamin d or high dose vitamin D
Also treat with bisphosphonates if severely osteopenic.
CKD induced hypocalcemia
Decreased Vitamin D conversion causes decreased Ca and Phos, so increased PTH. (2 hyperparathyroidism)
Causes of hyperkalemia
Iatrogenic, trauma, hypoaldosteronemia (acei, arb, spironolactone), ESRD, diet
How to work up hyperkalemia
Recheck, then get an EKG, if any changes (peaked T waves, long qrs, give ca gluc, will eventually cause torsades.
If no ekg changes, not emergent so give kayexalate or lasix.
Treatment options for hyperkalemia
Insulin w/D50, bicarb or albuterol, decreases EC K but no change inTBK
From GI losses or renal losses (hyperaldosteronism, diuretics, barters syndrome, gittleman's)
Ekg shows flat T waves and U waves.
Just replete K. PO is better than IV.
How to work up kidney stone?
Do a UA first, no blood, no stone.
Then do spiral CT scan or ultrasound if pregnany
How to treat kidney stone
Fluid, pain meds, tamsulosin
How to treat kidney stone between 5 mm and 3 cm
How to treat kidney stone >3cm
Surgery, then later, strain urine and type, followed by 24 h urine catch.
Types of stones
Ca oxalate (envelope), radioopaque
Struvite (coffin), radioopaque, proteus
Cysteine (hexagon), radiolucent
Uric acid (rhomboid), radiolucent, gout or increased turnover.
Simple renal cyst (pt, dx tx)
Patient: asymptomatic, small no loculations.
No need for diagnostic tests or treatment
Complex renal cyst
Patient has a flank mass that can cause infection and hematuria. Evaluate with CT, u/s if pregnant. Then biopsy, tx: resection
Flank mass, increased EPO, hematuria. CT scan or us if prenant. DO NOT BIOPSY.
Tx: nephrectomy, ex vivo pathology.
Infants. Complete renal failure, aneuric. Dx with ux. Radially oriented cysts.
Flank mass, infections, bleeds. CT scan. Biopsy. Supportive then transplant.
Minimal change disease
Associated with hodgkins, children
Associated with blacks, aids, heroin use.
In whites, hep b and c, solid tumors