Acute Renal Failure Flashcards
acute renal failure
inability to kidney to carry out Fx (ultrabsorption & reabsorption)
- l/o renal Fx –> dec urine output –> azotemia & fluid-lyte imbal
- Typically reversible but can progress to chronic renal failure
GFR and acute renal failure
GFR may dec within hours or days of acute renal failure
GFR requirements
- urine vol
- creatinine in blood + urine
oliguria output
100-400mL/day ~
anuria output
<100mL/day
etiology
- prerenal: Ischemic/circulatory problem prevents proper perfusion to kidney (ex. hypotension or hypovolemia)
- intrarenal: Glomerular nephritis (problem within kidney)
- postrenal: Obstr prevents urine to flow out of kidney (ex. BPH)
80-90% of ARF is which type of renal failure
prerenal or intrarenal
patho of prerenal
Ex. Hemorrhage –> lose blood vol –> inadequate perf to glomerular –> ischemia & ischemic damage –> dec filtration
patho of intrarenal
Acute tubular necrosis (ATN) –> nephrotoxic drugs, intratubular obstr (days or wks to happen)
patho of post renal
Ex. BPH –> hydronephrosis –> ARF
- obstr to urine flow
3 phases of ARF
1) initiating phase
2) maintenance phase
3) recovery phase
initiating phase duration
Lasts from precipitating event to the time mnfts appear
- hours to days
maintenance phase characteristics
- dec GFR
- oliguria
- azotemia
- fluid retention
cmplx from fluid retention
- HTN
- edema
- pulmonary congestion
recovery phase
Gradual inc in GFR as tissue repaired
non-oliguric forms of renal failure
Problem detected earlier d/t better screening techniques
mnfts
- oliguria or anuria
- fluid-lyte imbal
- azotemia
- proteinuria, hematuria
azotemia
buildup of nitrogenous wastes that can impact vital organs (ex. brain)
Dx
- renal Fx tests (BUN, GFR, creatinine)
- RIFLE
- creatinine clearance rate to estimate GFR
- new early biomarkers
RIFLE
- Risk (of running into renal failure)
- Injury (actual damage in kidney)
- Failure (some kind of renal failure has begun)
- Loss (l/o renal fx, mnfts appear)
- End stage renal disease (kidney shuts off and pt will die)
creatinine clearance ratio
Amount of creatinine in blood, urine & amount of urine excreted
new early biomarkers example
Interleukin-18
Interleukin-18
mediator produced w/ inflm in proximal tubule when there is ischemic damage
- Early indictor of renal failure b/c proximal tubule will be first area to be affected within kidney
Tx
- reversible (not self-limiting)
- STAT intervention
- cautious fluid & electrolyte replacement
- diet (adequate proteins)
- dialysis
why must you be careful with protein intake with ARF
Protein broken down into ammonia (nitrogenous waste), limiting protein ingestion helps to avoid/dec azotemia
types of dialysis
- hemodialysis
- peritoneal dialysis
- intermittent dialysis
- CRRT (continuous oral replacement therapy)
hemodialysis
blood filtered externally from body through dialyser (artificial kidney)
peritoneal dialysis
dialysate introduced into peritoneum, which acts as semi-permeable membrane that wastes filtered through
intermittent dialysis duration
over few hours
CRRT (continuous oral replacement therapy)
- slower than intermittent
- different methods used (convection, diffusion, or both)
