Acute Kidney Injury (AKI) Flashcards
define AKI
an abrupt reduction in kidney function defined by:
inc in creatinine by >50%
reduction in urine output
THAT WONT RESPOND TO RESUS
what would be defined as an “abrupt” reduction in kidney function?
<48hrs
risk factors for AKI?
old age CKD diabetes HF liver disease PVD previous AKI
what acute vascular problems can cause AKI?
hypotension
hypovolaemia
pre-renal causes are also know as…
functional causes
renal causes are also known as…
structural causes
post renal causes are also known as…
obstructive causes
what is affected first in AKI:
urine output
creatinine levels
UO
pre-renal causes of AKI?
hypovolaemia (eg dehydration)
hypotension
renal hypoperfusion
what drugs can cause renal hypoperfusion?
NSAIDs
COX-2 inhibitors
ACEi
what must be communicated to a renal patient when they’re started on an ACEi?
sick day rules - if they take their medication while ill theyre at risk of AKI
untreated pre-renal AKI leads to….
acute tubular necrosis
what forms of shock can cause AKI?
cardiogenic
septic
anaphylactic
define oliguria?
<0.5mls/kg/hr
how does angiotensin 2 increase GFR?
mediates arteriolar vasoconstriction
how does ACEi decrease GFR?
cause efferent arteriolar vasodilation
commonest form of AKI in hospital?
acute tubular necrosis
causes of acute tubular necrosis?
sepsis
severe dehydration
rabdomyolysis
drugs
Tx of pre-renal AKI?
assess for hydration eg oedema/JVP/cap refill
if deplete give 0.9% NaCl 1l
main drug causes of interstitial nephritis
- antibiotics
2. PPIs
non-drug causes of interstitial nephritis?
TB
sarcoidosis
patients who are itchy are more likely to have __ renal failure
chronic
gentamicin is toxic to what part of the kidney?
tubules
symptoms of AKI?
general symptoms eg nausea
itch
fluid overload eg oedema, sob
signs of AKI?
oliguria
fluid overload
uraemia eg itch, pericarditis
if blood and protein are in the urine the AKI is more likely to be of a ___ cause
renal/structural
Hx of sore throat in a patient with AKI?
could have a strep GN leading to AKI
what results on blood tests could indicate renal causes of AKI?
eosinophilia
CK
Ix for AKI?
U+Es, FBC coagulation screen urinalysis USS immunology for ANA/ANCA protein electrophoresis and BJP
what are the different components of U+Es?
Na, K, Ur, Cr
anaemic patient with a vague history indicates chronic or acute disease?
chronic
small kidneys indicate…
chronic disease
measurement for goodpastures?
GBM
investigations for myeloma?
protein electrophoresis
BJP
when would you do a renal biopsy urgently?
rapidly progressive GN
positive immunology + have AKI
Ct guided biopsy is the gold standard for renal biopsy?
F, USS guided biopsy is
if the patient has been fluid rescitated and still doesnt have a good BP what should you do?
give inotropes and vasopressors
when should a patient with AKI go onto dialysis?
if patient remains anuric and uraemic after treatment
what is fluid overload?
pulmonary oedema with oliguria
when should diuretics absolutely not been given in a patient with oedema symptoms?
if they are not peeing
what level is classed as severe uraemia?
urea >40
what is the cause of AKI in post renal AKI?
obstruction
get obstruction of urine flow leading to back pressure -> hydronephrosis -> loss of concentrating ability
causes of post renal AKI?
stones
cancers
strictures
extrinsic pressure
Tx of post renal AKI?
catheter
nephrostomy
normal K level?
3.5-5
patient with muscles feeling like jelly 2 days after dialysis?
hyperkalaemia
Ix for hyperkalaemia
muscle tests
ECG
why do we give calcium gluconate in hyperkalaemia?
stabilises myocardium and normalises ECG
what does insulin do in hyperkalaemia?
moves K+ back into the cells
Tx of hyperkalaemia
- calcium gluconate
- insulin dextrose
- sodium bicarbonate
indications for dialysis in an AKI patient?
not responding to drugs in: hyperkalaemia severe acidosis (<7.15) fluid overload urea >40 with pericardial rub
