AKI, CKD, and Dialysis Flashcards
What is another name for acute kidney injury
Acute renal failure but AKI preferred
What does AKI increase your risk of
mortality 5x
progression to CKD
how do you define AKI
acute reduction in function (GFR, UOP) and accumulation of nitrogenous wastes (BUN/creatinine)
what are the three different formal definitions of AKI
acute dialysis quality improvement initiative (ADQI) RIFLE scheme
Acute Kidney injury Network definition (AKIN)
Acute kidney injury working group of KDIGO
what does ADQI stand for
acute dialysis quality improvement
what does AKIN stand for
acute kidney injury netrowk
what does KDIGO stand for
kidney disease: improving global outcomes
What is RIFLE criteria
Risk
injury
failure
loss
ESRD
changes must be within 7 days
what is AKIN criteria
exclude easily reversible causes first
make sure adequately resuscitated
changes in 48 hours
What are the diagnostic criteria for AKI with KDIGO
increase in SCr by 0.3+ mg/dL within 48 hours
increases in SCr 1.5+ times baseline, known or presumed in last 7 days
urine volume less than 0.5 mL/kg/h for 6 hours
what are the three types of AKI
pre-renal
intra-renal
post-renal
what is pre-renal AKI
most common
hypoperfusion: low volume, bad pump, vasodilation, intra-renal vasoconstruction
what is intra-renal AKI
85% due to ATN: ischemic, nephrotoxic
glomerulonephritis
what is post-renal AKI
obstruction
What is ATN
Acute Tubular Necrosis
aka acute renal tubular necrosis
what is the number one cause of intra-renal aki
acute tubular necrosis
what can cause acute tubular necorsis
ischemic
infection
nephrotoxins
what is the presentation of AKI
many asymptomatic
may have encephalopathy
may have bleeding/anemia
may have normal or abnormal urine output (UOP)
what antibiotics are nephtrotoxic
AG abx (aminoglycosides)
amp B
sulfa, acyclovir
tenofovir, vanco
etc.
what is oliguria
< 400mL/day
what is anuria
< 100 mL/day
What labs are ordered with concerns for AKI
CBC
CMP
Urinalysis: sodium osmolality, specific gravity, microscopic exam, FENa
if urine sodium is <20 what is the likely cause of AKI
pre-renal
what is the urine sodium level for AKI with intra-renal cause
> 40
What is FENa
Fractional excretion of sodium
helps to differentiate between pre-renal and intrarenal (ATN)
*need urine and blood
what is a FENa of < 1%
pre-renal cause
what is a FENa of >2%
intra-renal cause
what is the UOP with pre-renal AKI
decreased because less volume
what is the first line imagine for AKI
renal ultrasound
looks for obstruction
when is renal biopsy indicated
if pre- and post-renal causes and ATN is excluded
what is the treatment of AKI
supportive: avoid additional injury, maintain perfusion/volume, +/- renal replacement therapy (RRT)
Prevention (KDIGO reccomendations)
What is CKD
chronic kidney disease
what are risk factors for CKD
hypertension
DM
small birth weight
childhood obesity
hx immune d/o
increasing age
black race
+fhx
structural/anatomic abnormalities
what manifests as gradual decline in kidney function weeks to years
CKD
how do we measure the decrease in kidney function
GFR
What is the presentation of CKD
early on, asymptomatic (stage 1 and 2)
Stage 3-4 +/- vague symptoms: HTN, anemia, fatigue, decreased appetite, malnutrition, electrolyte abnormalities
Stage 5 (ESRD) worsening nutrition, electrolyte and mineral disturbances
what is uremic syndrome
symptoms due to accumulations of nitrogenous waste
what are symptoms of uremic syndromes
fatigue
anorexia
nausea
metallic taste
irritability, insomnia
memory impairment
restless leg, paresthesias, muscle twitching
puruitis
decreased libido, menstrual changes
asterixis, myoclonus
What is the hallmark lab for CKD
persistent reduced GFR > 3 months
what is the study of choice for CKD
renal US
how do we manage CKD
goal is to limit progression
good control of DM
good BP control
good control of cholesterol
achieve and maintain healthy DMI
optimize CVD risk factors
maintain healthy diet
dose adjust meds as needed
avoid nephrotoxins
What is the mainstay of treatment for ESRD
renal replacement therapy (RRT)
hemofiltration, hemodialysis, peritoneal dialysis
what is the definitive treatment of CKD
renal transplant
what are complications of CKD
1 cause of mortality in CKD is CVD
#1 complication of VCD is HTN
metabolic bone disease
anemia
coagulopathy
hyperglycemia
What is RRT
techniques that ‘replace’ the filtration of the dysfucntional kidneys
What does RRT include
hemofiltration
hemodialysis: continuous, intermittent
peritoneal hemodialysis
What is the most common RRT modality
intermittent hemodialysis
when is continuous hemodialysis used
AKI and unstable patients
Who gets RRT
fluid overload unresponsive to diuretics
hyperkalemia, hypercalcemia and metabolic acidosis unresponsive to treatment
uremia
GFR <10 if no DM; GRF < 15 in DM
certain toxins
What are the two processes of RRT
Diffusion and oconvection
what is diffusion RRT
movement of particles down a concentration gradient
what is convection RRT
movement of particles AND WATER down a pressure gradient (hydrostatic pressure)
what does dialysis remove (solutes)
Na+, Cl-, K+, HCO3-, Ca2+, Mg2+, urea, creatinine, uric acid
