Nephrology Lecture Flashcards
(65 cards)
what is the term used for elevated nitrogen containing compounds (urea, creatinine) in the blood?
azotemia
what is the term for symptomatic azotemia? what type of acid/base disorder will these patients have?
uremia
metabolic acidosis
according to KDIGO guidelines, what are the criteria for defining acute kidney injury?
1) rise in creatinine greater than 0.3 mg/dL
2) decrease in UO to less than 3 mL/kg over 6 hours
what is the most common presentation of acute kidney injury? what are some other presentations?
frequently asymptomatic with NO visible signs
other: HTN, edema, decreased UO
what will labs look like in AKI?
albuminuria
increased BUN
hyperkalemia
hyponatremia
in general, what type of physiologic state causes prerenal azotemia?
hypovolemic states with decreased perfusion to the kidneys
can cause prolonged renal ischemia
which two chronic conditions cause prerenal azotemia?
CHF and hepatic failure (cirrhosis) due to third spacing and hypoperfusion
which two more acute conditions cause prerenal azotemia?
1) dehydration (inadequate PO intake, GI losses, diuretics)
2) sepsis
type 1 renal tubular acidosis occurs where in the renal tubules? what problem does it cause?
type 1 = distal
causes decreased tubular H+ excretion – hypokalemia
type 2 renal tubular acidosis occurs where in the renal tubules? what problem does it cause?
type 2 = proximal
causes decreased proximal HCO3 reabsorption and hypokalemia
type 4 renal tubular acidosis causes impaired ____ and ____ excretion
type 4 = impaired hydrogen and potassium excretion
an ______ deficiency, as seen in addison’s disease and DM, is likely to cause type 4 renal tubular acidosis
aldosterone deficiency
we need aldosterone to help us excrete potassium, without it we become hyperkalemic
glomerulonephritis, nephrosis, minimal change disease, and nephritis are all causes of what type of renal azotemia?
intrinsic acute kidney injury
he did a terrible job at explaining these. but flip the card for a brief explanation of
1) glomerulonephritis
2) interstitial nephritis
3) acute tubular necrosis
1) glomerulonephritis – see RBC casts and blood on urinalysis
2) interstitial nephritis – caused by nephrotoxic drugs (NSAIDS, lithium), INFECTION, etc. – see WBC casts on urinalysis
3) acute tubular necrosis – causes are prolonged ischemia, contrast reaction, sepsis – see muddy brown casts (or nothing) on urinalysis
what are a few causes of postrenal AKI azotemia?
urinary obstruction!
prostatism, bladder, pelvic or retroperitoneal tumors, calculi, urethral obstruction
why might a low hemoglobin/hematocrit indicate renal disease?
kidneys responsible for making erythropoietin for RBC stimulation
what are the two ways we can prevent AKI?
1) sustain renal perfusion (fluid balance, BP maintenance)
2) don’t clog the pipes (see next card)
how can you prevent AKI in the following situations?
1) about to give contrast dye to someone with weak kidneys
2) patient presents with hemolysis and/or rhabdomyolysis
1) aggressive IVF to limit contact w/ kidneys or avoid exposure if possible
2) aggressive IVF to protect kidneys
what is the MOST important component of diagnosing AKI?
identify the underlying cause
almost can ALWAYS reverse AKI in a normal healthy patient
if patient is developing profound hyperkalemia, what can we give?
kayexelate
what are the four MC etiologies of chronic kidney disease?
1) AKI
2) HTN
3) DM
4) vascular disease
microalbuminuria is defined as ____ albumin in the urine
30-300 mg/24 hour period
what levels indicate microalbuminuria on a spot urine albumin-to-creatinine ratio in men vs. women?
17-250 mg/g (men)
25-355 mg/g (women
anything lower = normal
anything higher = albuminuria
what are the 5 (technically 6) stages of kidney failure with their corresponding GFR?
1: GFR greater than 90 2 (mild): GFR 60-89 3 (mod): GFR 45-59 4 (mod): GFR 30-44 4 (sev): GFR 15-29 5 (ESRD): GFR less than 15
