Oliguria and AKI Flashcards
What is classified as oliguria?
less than 0.3ml/kg/hour for at least 24 hours
Define AKI?
marked decrease in GFR occurring over abruptly over 7 days
What classification is used to assess AKI and how many stages does it have?
KDIGO classification with 3 stages
What 2 things does KDIGO classification take into account when it comes to level of kidney failure?
Creatinine levels and UO
What creatinine levels above baseline warrant stage 1, 2 and 3 kidney disease?
Creatinine 1.5-2 times baseline within 7 days is stage 1
Creatinine 2-3 times baseline within 7 days is stage 2
Creatinine over 3 times baseline within 7 days is stage 3 or if its over 350 (alongside either an acute rise of 26 in 48 hours or over 50% of baseline in 7 days)
What urine output warrants stage 1, 2, 3 kidney disease on the KDIGO scale?
UO less than 0.5ml/kg/hr for 6 hours is stage 1
UO less than 0.5ml/kg/hr for 12 hours is stage 2
UO less than 0.3ml/kg/hr for 24 hours or anuria for 12 hours is stage 3
13 risk factors for AKI?
History of diabetes Sepsis Hypertension Age over 65 Heart failure History of chronic kidney disease Nephrotoxic drugs Contrast agents Oliguria Worsening NEWS Liver disease Urinary obstruction Hypovolaemia
3 classifications of renal injuries? What is the question you need to ask about each one?
Pre-renal - is there decreased perfusion?
Renal - is there intrinsic kidney disease?
Post-renal - is there obstruction?
3 physiological responses in the kidneys that cause alterations in their perfusion?
RAAS - renin release causes angiotensinogin to convert to angiotensin 1
ACE converts angiotensin 1 to 2
Angiotensin 1 causes kidneys to release aldosterone
Aldosterone causes increase sodium reab and therefore increase blood pressure
What can dilate the afferent renal arteriole and what drug inhibits this and therefore dangerous in kidney disease?
Prostaglandins dilate afferent arteriole and inhibited by NSAIDs and therefore need to be stopped
What 2 drug classes inhibits the physiological response to constrict the efferent arteriole in the kidney?
ACEi/ARBs
What can causes post renal obstruction?
Ureteric tumours, bladder tumours, external tumours compressing tract, prostatic issues, renal stones
If someone has a catheter in place and post renal obstruction is suspected, what needs to be done?
Flush the catheter to check for patency
First line imaging tool used for suspected post-renal obstruction?
USS for renal size, hydronephrosis, lesions, calculi
What is the CT scan you can order on renal tracts?
CT KUB
