Definition: acute kidney injury (AKI) is failure of the kidneys to regulate electrolyte, acid-base and fluid homeostasis adequately with concomitant reduction in glomerular filtration rate (GFR). pRIFLE (paediatric Risk, Injury, Failure, Loss, End-Stage Criteria).
Chronic renal failure: hyperfiltration, estimated creatinine clearance <75 ml/min/1.73m2 , hypertension, microalbuminuria.
Causes:
Multi-organ failure, congenital heart surgery, nephrotoxic substances, stem-cell transplantation, sepsis, HUS.
| pRIFLE | ||
| Grade | estimated Crea Clearance | Urine Output |
| Risk | decrease by 25 % | < 0.5 ml/kg/hr for 8 hours |
| Injury | decrease by 50 % | < 0.5 ml/kg/hr for 16 hours |
| Failure | decrease by 75 % or< 35 ml/min/1.73m2 | < 0.3 ml/kg/hr for 24 hours or anuric for 12 hours |
| Loss | persistent failure > 4 w | |
| End Stage | persistent failure > 3 mo | |
Causes:
AKI, dysplasia, renal reflux, obstructive nephropathy, chronic GN.
Options for renal replacement therapy (RRT):
CVVHD (continuous venovenous haemodialysis – clearance via diffusion)
CVVH (continuous venovenous haemofiltration – clearance via convection)
CVVHDF (continuous venovenous haemodiafiltration – clearance via convection and diffusion), most commonly done, PD (peritoneal Dialysis), SCUF, IHD (intermittent haemodialysis).
| Comparison of Renal Replacement Therapy | |||
| Variable | PD | CRRT | IHD |
| Convection | + | +++ | |
| Diffusion | ++ | ++ | |
| Fluid control | – | ++ | ++ |
| Uraemia control | – | ++ | + |
| Vascular access | Tenkhoff | required | required |
| Anitcoagulation | not applicable | required | required |
References:
[1] Kidney International 71, 2007, 1028 – 1035, Akcan-Arikan et al: Modified RIFLE criteria in critically ill children with acute kidney injuryAKI in critically ill children
[2] Am J Kidney Dis. 2005, Jan;45(1):96-101: Hui-Stickle et al: Pediatric ARF epidemiology at a tertiary care center from 1999 to 2001
[3] Adv Chronic Kidney Dis, 2008 July ; 15(3): 278-283: Goldstein et al: PROGRESSION FROM ACUTE KIDNEY INJURY TO CHRONIC KIDNEY DISEASE: A PEDIATRIC PERSPECTIVE: An invited review for Advances in Chronic Kidney Disease
[4] Pediatr Nephrol, 2009, 24: 37-49: Walters et al: Dialysis and pediatric acute kidney injury: choice of renal support modality
[5] Pediatr Nephrol. 2005 Jul;20(7):972-6: McNiece et al: Adequacy of peritoneal dialysis in children following cardiopulmonary bypass surgery
[6] Schrier: www.kidneyatlas.org
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