Acute Renal Failure Flashcards
what are the 2 primary things kidney does?
-ultrafiltration & reabsorption
what is Acute renal failure?
- loss of renal function:
- fluid & electrolyte imbalance
- azotemia (build up of nitrogenous wastes) - glomerular filtration rate decreases (hrs to days)
- TYPICALLY REVERSIBLE
what is the normal urine volume a day?
1,500ml
the kidney has enormous________ reserve
functional
what is the minimum volume of urine a day that has to be produced to prevent azotemia?
400ml/day
what is oliguira
100-400ml/day
anuria
less than 100ml day
what is the etiology of acute renal failure?
3 groups:
- prerenal (cardiac problem not enough blood going to kidneys) (primary reasons: hypotension & hypovolemia
- intrarenal
- postrenal
Prerenal causes of acute renal failure
Hypovolemia: -hemmorhage -dehydration -excessive loss of gastrointestinal tract fluids -excessive l/o fluid d/t burn injury Decreased Vascular Filling: -anaphylactic shock -septic shock Heart Failure Or Cardiogenic Shock Decreased Renal Perfusion: d/t sepsis, vasoactive mediators, drugs diagnostic agents
Intranrenal causes of acute renal failure
Acute Tubular Necrosis:
-prolonged renal ischemia
Exposure Of Nephrotoxic Drugs, Heavy Metals & organic solevents
Intratubular Obstruction: resulting from hemoglobinuria, myoglobinuria, mycloma light chains or uric acid casts
Acute Renal Disease ex. (acute glomerulonephritis, pyelonephritis)
_____ & _____ account for approx 80%-90% of acute renal failure
prerenal& intrarenal account for approx 80-90% if acute renal failure, primary reasons: hypotension & hypovolemia
Patho of acute renal failure(3 phases of acute renal failure)
Initiating phase:
-precipitating event to tubular injury (means injurious event that leads to tubular injury)
Maintenance phase:
-Decrease in GFR, Oliguria
-azotemia
-Complications: Edema, pulmonary congestion, hypertension (from fluid retention)
Recovery phase:
-gradual tissue repair with increase in GFR (glomerular filtration rate)
what are the 3 phases of acute renal failure
- initiating phase:
- maintenance phase
- recovery phase
patho of acute renal failure caused by prerenal
inadequate renal perfusion (eg. hemorrhage) (-kidney receives blood for 2 reasons: function & own resources) causes oliguria & ischemia
THEN 3 PHASES
patho of acute renal failure caused by intrarenal
acute tubular necrosis:
-nephrotoxic drugs, intratubular obstruction
THEN 3 PHASES
patho of acute renal failure caused by postrenal
eg. BPH
obstruction to urine flow
THEN 3 PHASES
manifestations of acute renal failure
-oliguria or anuria
-can encounter non-oliguric acute renal failure (clinically may encounter, particularly in elderly pateints), volume of urine normal but has acute renal failure (unclear answer why- suggestion-now earlier detection of cardiac problems then cardiac problems dealt with.
-fluid electrolyte imbalance
-azotemia
-proteinuria, hematuria
Complications: -edema & hypertension
what are the complications of acute renal failure?
-edema & hypertension
diagnosing acute renal failure
- GFR
- BUN (blood, urea, nitrogen), creatinine
- urine volume
- RIFLE (risk, injury, failure, loss, endstage renal disease)
- rifle uses creatinine, GFR & urine output
- new: early biomarkers (eg. IL18 -interleukin 18, inflammatory mediator, interleukin produced in proximal tubule physiologically)
what is an assessment used to diagnosis acute renal failure and what does it involve?
- RIFLE (risk, injury, failure, loss, endstage renal disease)
- rifle uses creatinine, GFR & urine output
what is a biomarker that indicates acute renal failure?
IL18 -interleukin 18, is an inflammatory mediator, interleukin produced in proximal tubule physiologically, damaged and then is released
Treatment of acute renal failure
ACUTE RENAL FAILURE IS REVERSIBLE
- stat intervention (the sooner you intervene the better the outcome)
- cautious fluid & electrolyte replacement(because pt in renal failure)
- Diet modification(adequate calories though): low sodium(salt in blood) & low protein (protein breakdown release nitrogenous wastes, pt already has azotemia, adding to nitrogenous waste build up)
- Intermittent dialysis: hemodialysis(filtrating blood through artificial kidney) peritoneal dialysis(can also be used)
- CRRT-continuous renal replacement therapy(continuous 24hrs, ICU setting, diffusion or convection & combined)
what is chronic renal failure
-progressive permanent renal damage
what are the progressive states of chronic renal failure?
Diminished renal reserve(referring to functional reserve fx of kidney dropped):
- GFR less than 50% of normal (normal=120-130ml)
- because of large functional reserve asymptomatic (no signs of decreased renal function)
Renal insufficiency:
-GFR 20-50% of normal
Renal failure:
- GFR less than 20%
- End stage -GFR less than 5%
