Aki Flashcards
What is AKI
Abrupt disruption of kidney function including but not limited to acute renal failure
Which kidney is higher?
Left
Which peritoneal section are the kidneys
Retroperitoneal
Functions of the kidney
Acid base balance
Hormone regulation
Electrolyte balance
Blood pressure regulation
Toxin removal
Water balance
Where is both H+ and HC03- secreted in the kidney?
Proximal tubule
Where is H+ secreted in the kidney?
Proximal tubule and collecting ducts
What electrolyte determines ECF volumeV
Sodium
Perfusion of what allows the functioning of RAAS
Juxtaglomerular apparatus
How does the kidney regulate BP?
Volume of ECF (with sodium)
RAAS
What causes ADH secretion
Detection of increased plasma osmolality by hypothalamus
Where is ADH secreted from
Posterior pitusitarh gland
What toxins does the kidney remove?
Urea
Creatinine
Drug metabolites
How are toxins filtered by the kidney?
Glomerular filtration
Passive diffusion
Active transport
What can high urea cause
Uraemia encephalopathy
Uraemia pericarditis
What is the criteria for an AKI?
Rise in serum creatinine 26micromol/L or greater in 48 hours
50% greater rise in serum creatinine (more than 1.5x baseline) in last 7 days
Fall in urine output <0.5ml/kg/hour for > 6 hours - catheterised
What signs and symptoms should u suspect AKI in
N+V, diarrhoea, signs dehydration
Reduced urine output or colour change
Confusion, fatigue, drowsiness
What are methods of staging for AKI?
RIFLE criteria
KDIGO system
What is second stage AKI defined by?
100-199% creatinine rise from baseline in 7 days
Urine output <0.5ml in 12 hours
What criteria is 3rd stage AKI?
200% creatinine rise, 354 micro mil/L or more with acute rise
Urine output <0.3ml/kg/hr 24 hours, anuria for 12 hours
Risk factors for AKI
Diabetes
Emergency surgery
Intraperitoneal surgery
CKD if eGFR <60
Heart failure
Age over 65
Liver
Use nephrotoxic drugs
drugs need to stop in AKI
DAMN
Diuretics
ACEis/ARBs
Metformin
NSAIDs
Causes of loss of glomerular filtration rate (features of AKI)
Circulating volume overload
Hyperkalaemia
Acidosis
What reduces hydrostatic pressure in the glomerulus?
Hypotension
Renal artery stenosis
ACEi - efferent arteriole dilation
NSAIDs - afferent arteriole dilation
(NSAID +ACEi BAD)
What increases hydrostatic pressure in glomerulus
Urinary tract obstruction, hypertension