Renal failure Flashcards
Acute renal failure?
inability for the kidney to carry out its function
what are some of the main functions of the kidney?
ultrafiltrations and reabsorption
Acute?
arises abruptly and/or for a short duration
Briefly summarize renal failure.
loss of renal function = decrease urine output = azotemia and fluid electrolyte imbalance
Azotemia and electrolyte imbalance can have an impact on other organs of the body. Explain a few organs affected
- waste sent to the brain = encephalopathy
- potassium imbalance = impacts the heart
is acute renal failure and chronic renal failure reversible?
Acute renal failure is reversible, chronic is not.
What does GFR require in order to be measured?
urine volume + creatinine in blood and creatinine in urine
Oliguria?
100-400 mL of urine output per day
Anuria?
Less than 100 mL of urine output per day
Etiology of ARF?
- prerenal
- infrarenal
- poystrenal
Prerenal?
ischemic/circulatory problem preventing proper perfusion to the kidney (HypoTN or hypovolemia)
Intrarenal?
problem with the kidney eg. glomerular nephritis
Postrenal?
preventing obstruction of urine flow out of the kidney (eg. BPH)
Explain the patho regarding prerenal
Eg. hemorrhage -> lose blood volume = inadequate perfusion to glomerulus -> ischemia and ischemic damage -> decreased filtration
examples of intrarenal
eg. acute tubular necrosis (ATN) -> nephrotoxic drugs, intratubular obstruction (takes days or weeks to happen).
What are the 3 phases that occur in intrarenal?
- initiating phase
- maintenance phase
- recovery phase
Initiating phase?
(hours-days) Lasts from trauma event to the time that manifestations become apparent
Maintenance phase?
refers to maintaining the problem, not maintaining the kidney function. Decrease GFR, oliguria, azotemia, fluid retention (HTN, EDEMA, PULMONARY CONGESTION)
Recovery phase?
offending event that has been addressed (gradual increase in GFR as tissue is repaired)
How can BPH cause ARF?
BPH -> hydronephrosis -> ARF
Manifestations?
- oliguria or anuria
- fluid-electrolyte imbalance
- azotemia
- proteinuria, hematuria
Complications?
HTN, EDEMA, PULMONARY CONGESTION
Diagnostics?
- renal function tests : BUN, Creatinine, GFR
- RIFLE
- new early biomarkers (eg. interleukin-18)
RIFLE?
Risk, injury, failure, loss, end stage renal failure
- risk = risk of running into renal failure
- injury = actual damage in the kidney
- failure = some kind of renal failure has begun
- loss = loss of renal function (mnfts apparent)
- E = ESRD -> kidney shuts off and the pt will die
What is interleukin 18?
a mediator produced together with inflammation in the proximal tubule when there is ischemic damage
Which area of the kidney is usually the first to be affected during renal failure?
Proximal tubule
Treatment?
- reversible but not self-limiting
- STAT intervention
- Cautious fluid and electrolyte replacement
- Diet -> careful protein ingestion
- dialysis (hemo/peritoneal/intermittent dialysis/CRRT)
Why is a protein restricted diet suggestion?
protein is broken into ammonia, which is a nitrogenous waste so limiting protein ingestion will help to avoid or decrease azotemia.
Hemodialysis?
blood is filtered externally from he body through a dialyser which acts as an artificial artery
Peritoneal dialysis?
dialysate introduced into the peritoneum which acts as a semi-permeable membrane which wastes are filtered through
CRRT?
continuous renal replacement therapy
Chronic RF?
progressive, permanent damage
List the stages of chronic renal disease.
- Diminished renal reserve stage
- Renal insufficiency
- renal failure
Diminished renal reserve stage?
GFR is less than 50% of normal. GFR is about 60 mL/min which is still adequate for filtration. No signs of decreased renal function.
Does the kidney have a large functional reserve?
YES
Renal insufficiency?
GFR is 20-50% of normal (inadequate filtration)
Renal failure?
GFR is less than 20%. The kidney will shut down once the GFR is <5%
