- Renal insult common in PICU patients
- Injury usually within first week of admission
- Early recognition is important
- Pay attention to urine output and Bun/Cr numbers
- Acute Kidney Injury is an independent risk factor for M & M
- Adjust doses of medications for renal function
- Pay attention to fluid balance in renal patients
- Insensibles (15-20%) plus output should be maintenance fluid requirement
- Higher dose of diuretics may be needed to convert from oliguric to non oliguric renal failure
- Fluid overload (20%) is an independent risk factor for M & M
Transplant patients
- Co-managed by transplant surgeons and nephrology
- Protocol established and available for all patients
- Ensure patient has adequate CVP and urine output
- Notify fellow and surgery for any changes in urine output
- Renal ultrasound with Doppler to investigate any vascular accidents in transplanted kidney
- Check Immunosuppression regimen with nephrology
RTA
- Systemic acidosis with alkaline urine
- A/w acidosis and dyselectrolytemia
- Needs Bicarb therapy for correction
- Electrolyte monitoring and replacement may be needed
Pediatric-modified RIFLE (pRIFLE) criteria
| Category | Estimated Cr Cl | Urine Output |
|---|---|---|
| Risk | eCCl decrease by 25% | 0.5 ml/kg/h for 8 h |
| Injury | eCCl decrease by 50% | 0.5 ml/kg/h for 16 h |
| Failure | eCCl decrease by 75% or eCCl 35 ml/min/1.73m2 |
0.3 ml/kg/h for 24 h or anuric for 12 h |
| Loss | Persistent failure > 4 weeks | |
| End Stage | End-stage renal disease (persistent failure > 3 months) |
Indications for pediatric RRT
- Fluid Overload (hypervolemia with pulmonary edema/respiratory failure) and/or electrolyte imbalance
- Uremia with bleeding and/or encephalopathy
- Acuity/degree of kidney injury: Reduction of GFR/elevated cratinine; reduction in urine output
- Intoxications
- Inborn errors of metabolism
- Nutritional support
Important concepts
Diffusion: solute transport across a semi-permeable membrane
- Molecules move from an area of higher concentration to lower concentration
- Effective for small molecule clearance
Convection: process where solutes pass across the semi-permeable membrane along with the solvent in response to a positive transmembrane pressure
- Effectiveness is less dependent on molecular size
RRT options
Hemodialysis, Peritoneal Dialysis, or Continuous RRT - each has advantages and disadvantages
Choice is guided by:
- Patient characteristics (disease/symptoms, hemodynamic stability)
- Goals of therapy (fluid removal, electrolyte correction)
- Availability, expertise, and cost
Continuous veno-venous hemofiltration (CVVH)
- Provides solute removal by convection
- Uses replacement fluid
Continuous veno-venous hemodialysis (CVVHD)
- Provides solute clearance by diffusion
- Uses dialysate fluid
Continuous veno-venous hemodiafiltration (CVVHDF)
- Provides solute removal by both convection and diffusion
- Uses both replacement fluids and dialysate fluids
*Proposed benefits of above three methods:
- Reduces hemodynamic instability
- Effective control of uremia, hyperphosphatemia, and hyperkalemia
- Rapid control of acid-base imbalance
- Allows for improved nutritional support
- Management of sepsis/plasma cytokine filter
Peritoneal dialysis (PD)
- Fluid removal follows an osmotic gradient, therefore more dependent on concentration of dialysis solution
- Clearance achieved by PD depends on size of molecule, dialysis fluid osmolality, dwell time, and volume of dialysis fluid
- Contraindications: defect in peritoneal membrane, abdominal problems
Intermittent hemodialysis
- Extracorporeal exchange of fluid and solute that occurs across an artificial semipermeable membrane between blood and dialysis fluid moving in opposite directions
- Children have to be hemodynamically stable and be able to tolerate interval between dialysis runs