Acute & Chronic Kidney Injury Flashcards
acute renal failure / acute kidney injury (AKI)
- abrupt disease in kidney function
- a rapid, progressive process
- difficult to detect
acute renal failure is reversible if
identified and treated early
acute renal failure is identified by
oliguria and elevated serum BUN and creatinine
elevation of BUN and creatinine =
azotemia
BUN and creatinine are both products of
protein metabolism
azotemia
medical condition characterized by increase levels of nitrogen in the body
risk factors for acute kidney injury
- hx of renal problems
- hx of htn
- hx od diabetes
- use of nephrotoxic agents
- exposure to heavy metals or organic solvents
- recent hypotensive episode
- tumor or vascular obstruction
- infection
-sepsis
common causes of acute kidney injury
- arterial occlusion
- absolute decrease in effective in blood volume
- relative decrease in blood volume
prerenal injury
caused by renal blood flow resulting in renal hypoperfusion and ischemia
prerenal injury causes a decreases in the
GFR
pre renal injury is often reversible? or irreversible?
reversible
causes of prerenal injury
- decreased cardiac output
- increased vascular capacity
- drugs that alter renal hemodynamics
acute tubular necrosis (ATN) is a type of _____ renal injury
intrinsic renal injury
what is acute tubular necrosis (ATN)
destruction of renal tubular epithelial cells
ATN is caused by
- ischemia
- sepsis
- vascular problems (such as malignant htn)
- acute glomerulonepritis and other infections
- drug allergies and toxicity
- rhabdomyolosis (breakdown of skeletal muscle and release of myoglobin which plugs glomeruli)
2 types of ATN
(1) ischemic
(2) toxic
ischemic ATN
prolonged hypoperfusion
(surgical procedure, anasthesia)
toxic ATN
from aminoglycoside anti-infectives, contrast induced nephropathy (CIN)
oliguric ATN
less likely to recover renal function
- has a high mortality rate
non-oliguric ATN
commonly seen with toxic injury
- renal concentrating defect
- hyperkalemia common complication
postrenal injury
caused by an obstruction to the outflow or urine from the kidneys
obstruction to one kidney does not likely lead to renal failure unless
the other kidney is not functioning or absent
uremia occurs when
2/3 of total number of nephron loss
fluid overload can lead to
HF, pulmonary edema, hear crackles
wastes can cause
homeostasis and anemic disorders when there are extra wastes
nursing care for AKI and fluid volume overload
diuretics, fluid restriction as prescribed, monitor for S&S of fluid volume excess, intake and output, oral care, ice chips
possible neurologic symptoms in pt with AKI
decreased mental function, peripheral neuropathy, cerebral edema
possible cardiovascular and pulmonary symptoms in pt with AKI
htn, pulmonary edema, electrolyte imbalance, pneumonia
possible GI symptoms in pt with AKI
poor appetite, GI bleeding, constipation, diarrhea
possible hematologic symptoms in pt with AKI
anemia, blood clots
possible integumentary symptoms in pt with AKI
pale appearance, bruising, pruritis, dry skin, thin hair, brittle nails, uremic frost
possible skeletal symptoms in pt with AKI
usteodystrophy
BUN reflects
GFR and urine concentrating capacity
BUN increases as GFR
decreases
BUN is affected by
hydration status, level of catabolism, protein intake, and GI bleeding therefore is not considered a reliable measure of GFR
creatinine is the end product of
muscle metabolism and is released into the blood at a constant rate
creatinine is eliminated at a rate =
equal to renal function
normal BUN and creatinine ratio is
10:1 or 15:1
what BUN:creatinine ratio is indicative of AKI
20:1
a decrease in creatinine clearance rate indicates a decrease in
glomerular function
normal BUN
3.6 - 7.1 mmol/L
normal creatinine
44 - 133 mmol/L
creatinine clearance =
urine creatinine x urine volume
diagnosis of AKI
(1) urine output
(2) renal insufficiency
(3) renal failure
(4) ESRD
in dx of AKI urine output would
diminished renal reserve - output may be normal as remaining nephrons are able to compensate
in dx of AKI renal insufficiency is
inability to concentrate urine and results in polyuria
renal failure =
oliguria
ESRD =
anuria
osmolarity is
serum and urine
osmolarity is the measure of
solute concentration/kg
what is a major factor that affects osmolarity
sodium
when renal function decreases, urine osmolality ______ and urine specific gravity _______, serum osmolality ________
increases; increases; stays the same
symptoms of metabolic acidosis related to renal tubule dysfunction
- hyperkalemia
- hyperventilation
- cardiac dysrhythmias
chronic renal failure (CRF)
the irreversible loss of renal function, affecting nearly all organ systems
what does chronic renal failure result from
primary renal condition (such as polycystic kidney disease, glomerulonephritis) or other diseases that affect the kidneys (diabetes, htn)
risk factors for chronic renal failure
diabetes mellitus, htn, proteinuria, family history, increasing age
in chronic renal failure regulation in GFR =
reduction in number of functional nephrons
in chronic renal failure kidneys compensate for damage by
hyperfiltration
hyperfiltration =
further loss of function over time
in chronic renal failure the kidneys experience generalized
wasting (shrinking) and progressive scarring
it is usually not until over ___% of kidney function is lost the pts start to experience symptoms
70%
cardiovascular S&S of chronic renal failure
- htn
- hf
- heart disease
- stroke
- peripheral vascular disease
- pericarditis
hematologic S&S of chronic renal failure
- anemia
- reduced erythropoietin
- GI blood loss
- iron deficiency
- thrombocytopenia
GI S&S of chronic renal failure
- nausea
- vomiting
- anorexia
- GI bleeding
neurologic S&S of chronic renal failure
- sleep disorders
- memory loss
- impaired judgement
- muscle cramps
- twitching
- asterixis
- seizures
- coma
- peripheral neuropathy
medical treatment for chronic renal failure (CRF) is aimed at maintaining homeostasis by
- reducing fluid volume overload
- monitoring electrolytes
- treating acid base imbalances
- treating and preventing infection
- metabolic imbalance
- treating electrolyte excess
for chronic renal failure (CRF) fluid overload is avoided by
- fluid restriction
- diuretics
for chronic renal failure (CRF) catabolic processes are avoided by
decreased protein intake = decreased protein diet
for chronic renal failure (CRF) electrolyte imbalances are avoided by
IV solutions with more free water; 0.45% saline or isotonic
types of renal replacement therapy (RRT)
(1) hemodialysis
(2) peritoneal dialysis
(3) continuous renal replacement therapy
how does renal replacement therapy work
dissolved particles are transferred across a semipermeable membrane from one fluid compartment to another
renal replacement therapy does not correct renal impairment but does correct _____
fluid, electrolyte, and acid-base imbalances, and removes waste products
hemodialysis
allows more gradual removal of excess electrolytes
- used in critical care setting so that ongoing assessment can occur
- uses 5 different methods to clear excess fluids
what 5 different methods are used in hemodialysis to clear excess fluids
(1) fluids
(2) solutes
(3) electrolytes
(4) creatinine
(5) urea
peritoneal dialysis
peritoneal cavity is used as the semipermeable membrane to removes wastes, excess fluids, and electrolytes
- a sterile catheter is inserted into the peritoneal cavity through the abdominal wall
- as dialysate solution is instilled through the catheter, waste and excess products cross the semipermeable peritoneal membrane and into the dialysate
- continuous or intermittent
peritoneal dialysis depends on
diffusion and osmosis
in peritoneal dialysis osmosis and a high glucose concentrate in the dialysate allows water to migrate from the ________ and into the
the blood and into the peritoneal cavity
advantages of peritoneal dialysis
- can be performed on a regular basis so that fluid and electrolyte shift is less dramatic
- can be performed in pt home
- ambulatory pts may work or do other activities while dialysis occurs
- if hemodynamically unstable there is a less dramatic alteration in fluid balance
disadvantages of peritoneal dialysis
- considerable infection risk
- respiratory distress associated with the volume of fluid and “dwelling”
- significant protein depletion
when a pt is on dialysis it is important to monitor and assess _________
monitor and maintain fistula and assess for bruit