AKI
AKI Dx criteria
stages of AKI?
1 - increase >26 mol/L within 48 hrs or 1.5 to 1.9 x reference creatinine.
Urine output <0.5 mL/kg/hr for > 6hrs
2 - increase 2 to 2.9 x reference creatinine
UO <0.5 mL/kg/ hr for > 12 hrs
3 - increase ≥3 X reference creatinine or
increase 354 μmol/L or commenced on renal replacement therapy (RRT) irrespective of stage
UO <0.3 mL/kg/ hr for > 24 hrs or anuria for 12 hrs
AKI causes ?
Pre-renal causes = Insufficient blood supply (hypoperfusion) to kidneys reduces the filtration of blood. Due to:
- Dehydration
- Shock (e.g., sepsis or acute blood loss)
- Heart failure
Renal causes are due to intrinsic disease in the kidney. Due to:
- Acute tubular necrosis
- Glomerulonephritis
- Acute interstitial nephritis
- Haemolytic uraemic syndrome
- Rhabdomyolysis
Post-renal causes = obstruction to the outflow of urine away from the kidney, causing back-pressure into the kidney and reduced kidney function = obstructive uropathy.
Obstruction may be caused by:
- Kidney stones
- Tumours (e.g., retroperitoneal, bladder or prostate)
- Strictures of the ureters or urethra
- Benign prostatic hyperplasia (benign enlarged prostate)
- Neurogenic bladder
AKI Px
AKI Ix
AKI Mx
what is Acute tubular necrosis (ATN)?
how does ATN present?
Acute interstitial nephritis (AIN) - causes Px and ix?
Px
- fever, rash, arthralgia
- eosinophilia
- mild renal impairment, HTN
Ix
- urine - sterile pyuria, white cell casts
Tubulointerstitial nephritis with uveitis (TINU)
Px
- fever, wt loss, painful red eyes
Ix
- urinalysis - leucocytes + protein
CKD
Chronic kidney function reduction - permanent + progressive
causes of CKD?
CKD Dx criteria
> 3mo of either:
- eGFR <60
- urine albumin:creatinine ratio (ACR) >3mg/mmol
CKD classification by eGFR
1 - >90
2 - 60-89
3a - 45-59
3b - 30-44
4 - 15-29
5 - <15
CKD Px
CKD Ix
CKD Mx
CKD Cx
Anaemia in CKD
Mx
- oral / IV iron
- EPO
CKD -MBD Ix and Mx?
Ix
- spinal XR - rugger jersey spine
Mx
- low phosph diet
- phosph binders - Ca based / can use sevelamer
- active vit D - calcitriol
- Ca in diet
- bisphosphonates for osteoporosis
Haemodialysis
Indications for short-term dialysis
A - acidosis - severe, not responding to tx
E - electrolyte abnormalities - eg tx-resistant hyperkalaemia
I - intoxication - OD
O - oedema - severe, unresponsive pulmonary oedema
U - uraemia sx - seizures, coma
Peritoneal dialysis
Cx
- peritonitis - add vanc / teic + ceftazidime to dialysis fluid