Children comprise less than 1% of the total haemodialysis population. The preferred mode of dialysis is peritoneal dialysis but chronic haemodialysis is viable in older children and in places where PD is not available. They should ideally be dialysed in a paediatric unit with facilities and personnel relevant to the child. In areas where the population is not sufficient to justify a separate unit, good care can be given in integrated paediatric and adult units with specialised staff.
15.2 Patient selection
Generally all children can be accepted for chronic haemodialysis except those who have no potential for rehabilitation.
15.3 Indications for starting dialysis
• Fluid overload resulting in cardiovascular instability
• Restriction of fluid intake resulting in inadequate nutrition
• School absenteeism from uraemic symptoms
• GFR < 10ml/min/1.73m2
• Reduced growth velocity
• Reduced head circumference
• Neurological developmental delay despite adequate nutrition Calculated GFR (ml/min/1.73m2) = 40 x height (cm)
creatinine (umol/l) 15.4 HD machine
The pump for maintaining and controlling blood flow should be accurate at low flow rates (up to 20ml/min)
15.5 Haemodialysers
• Should have a low priming volume and compliance, safe UF coefficient, high degree of biocompatibility and a predictable relationship between clearance and blood flow rates
• Total extracorporeal circuit volume is < 10% of child’s estimated blood volume (80ml/kg) i.e. extracorporeal volume is < 8ml/kg child’s body weight
• Dialyser surface area (m2) = 70 – 100% of child’s body surface area (BSA)
BSA = height (cm) x weight (kg) 3600
√
or refer to normogram
Table 15.1 Locally available paediatric dialysers
Manufacturer Material Model No. Surface (m2)
Volume (line)/ml
Fresenius Polysulfone F3 0.4 30
F4 0.7 42
F5 1.0 63
F6 1.3 82
Asahi AM-SD 300 0.6 40
AM-SD 400M 0.8 49
AM-SD 400U 0.8 49
15.6 Blood lines
Volume capacity of blood lines range from 13ml (neonatal) to 30ml (paediatric) to 120ml (adult)
15.7 Needles - as in adults (18G – 14G) 15.8 Vascular access
15.8.1 Temporary
Appropriately down-sized venous cannulas (single or double-lumen) can be inserted percutaneously into vena cava via internal jugular, femoral or subclavian approach.
15.8.2 Permanent Refer to adult section 15.9 Method of dialysis
• Blood pump flow = 5ml/kg/min
• Priming of the blood lines is necessary if the child is anaemic, if extracorporeal blood volume exceeds the recommended amounts.
Whole blood or 5% albumin can be used.
• Heparinisation: bolus 20 - 50 units /kg followed by 10 - 20 units/kg/hour. Activated clotting time (if used) should be kept 150 - 180 seconds
• Ultrafiltration rate: maximum fluid removal per session should be
< 5% of dry weight and rate of removal < 0.2ml/kg/min 15.10 Nutrition
Refer to Chapter 31
15.11 Growth
Children with CRF are growth retarded especially if renal failure starts in infancy and if the aetiology is congenital renal disease.
Growth rates based on age and sex are higher than expected in the youngest patients who are transplanted. Aim to transplant early especially if young.
15.11.1 The treatment goal for children on dialysis should include:
a. normal height velocity for age
b. ‘catch-up’ growth for those who are short at onset of dialysis 15.11.2 Children with short stature at onset of dialysis (height standard deviation score SDS < -1.88):
a. optimise dialysis
b. control renal osteodystrophy c. control acid-base balance d. correct anaemia
e. ensure adequate nutrition
f. recombinant human growth hormone (rhGH) (Level C)
15.12 Adequacy
• Currently no published outcome data in children with ESRD to suggest that any measure of dialysis adequacy is predictive of well-being, morbidity or mortality
• Achievement of numeric targets should not be the sole determinant of adequacy of care
(Level C)
15.13 Differences with adults:
• Greater size differences and dietary variations with resultant larger variations in PCR and urea generation rate
• Prescription of dialysis changes with growth
• In small children with relatively high clearances, the 2-pool model is preferred
15.14 Kt/V
• In the absence of specific data, it is recommended that delivered dose of HD should be equivalent to a single pool Kt/V urea of at least 1.3
• Higher Kt/V values which are relatively easy to achieve (relatively low V) may facilitate growth
• Measured dose of dialysis delivery should be done 3-monthly
15.15 Problems of patients on long-term HD As for adults plus:
• growth retardation
• delayed sexual maturation
• psychosocial problems
References
1. Handbook of Dialysis (3rd edition), 2001, 562-579. Daugirdas JT, Blake PG, Ing TS. Lippincott Williams and Wilkins
2. National Kidney Foundation. K/DOQI Clinical practice guidelines for hemodialysis adequacy, 2000. Am J Kidney Dis 2001(suppl 1); 37: S7-S64
3. Warady BA, Alexander SR, Watkins S, Kohaut E, Harmon WE. Optimal care of the pediatric end-stage renal disease patient on dialysis. Am J Kidney Dis 1999;
33: 567-583
4. Al-Hermi BE, Al-Saran K, Secker D, Geary DF.Hemodialysis for end-stage renal disease in children weighing less than10kg. Pediatr Nephrol 1999; 13: 401-403
5. Warady B, Watkins SL Current advances in the therapy of chronic renal failure and end stage renal disease. Semin Nephrol 1998; 18: 341-354.
6. Warady BA, Bunchman TE An update on peritoneal dialysis and hemodialysis in the pediatric population. Curr Opin Pediatr 1996; 8: 135-140
7. Bunchman TE .Pediatric hemodialysis: lessons from the past, ideas for the future.
Kidney Int Suppl 1996; 53: S64-S67
8. Donckerwolcke RA, Bunchman TE. Hemodialysis in infants and small children.
Pediatr Nephrol 1994; 8: 103-106
9. K/DOQI Clinical Practice Guidelines for nutrition in chronic renal failure. Am J Kidney Dis 2000(suppl 2); 35: S105-S136
10. Sharma AK Reassessing hemodialysis adequacy in children: the case for more.
Pediatr Nephrol 2001; 16: 383-390
11. Sharma A, Espinosa P, Bell L, Tom A, Rodd C Multicompartment urea kinetics in well-dialyzed children. Kidney Int 2000; 58: 2138-2146
12. Van Hoeck KJM, Lilien MR, Brinkman DC, Schroeder CH. Comparing a urea kinetic monitor with Daugirdas formula and dietary records in children. Pediatr Nephrol 2000; 14: 280-283
13. Goldstein SL, Brewer ED. Logarithmic extrapolation of a 15-minute postdialysis BUN to predict equilibrated BUN and calculate double-pool Kt/V in the pediatric hemodialysis population. Am J Kidney Dis 2000; 36: 98-104
14. Jiravuttipong A, Jones CL Natural logarithmic formula: not an alternative method for estimating Kt/V in paediatric haemodialysis. Nephrology 2000; 5: 167-171
15. Goldstein SL, Sorof JM, Brewer ED Evaluation and prediction of urea rebound and equilibrated Kt/V in the pediatric hemodialysis population. Am J Kidney Dis 1999; 34: 49-54
16. Goldstein SL, Sorof JM, Brewer ED Natural logarithmic estimates of Kt/V in the pediatric hemodialysis population. Am J Kidney Dis 1999; 33: 518-522
17. Verrina E, Brendolan A, Gusmano R, Ronco C Chronic renal replacement therapy in children; which index is best for adequacy? Kidney Int 1998; 54:
1690-1696
18. Harmon WE Kinetic modeling of hemodialysis in children. Semin Dial 1994; 7:
392-397
19. Hokken-Koelega A, Mulder P, De Jong R, Lilien M, Donckerwolcke R, Groothof J Long-term effects of growth hormone treatment on growth and puberty in patients with chronic renal insufficiency. Pediatr Nephrol 2000; 14: 701-706
20. Tom A, McCauley L, Bell L, Rodd C, Espinosa P, Yu G, Yu J, Girardin C, Sharma A Growth during maintenance hemodialysis: impact of enhanced nutrition and clearance.J Pediatr 1999; 134: 464-471
21. Berard E, Crosnier H, Six-Beneton A, Chevallier T, Cochat P, Broyer M Recombinant human growth hormone treatment of children on hemodialysis.
Pediatr Nephrol 1998; 12: 304-310
22. Turenne MN, Port FK, Strawderman RL, Ettenger RB, Alexander SR, Lewy JE, Jones CA, Agodoa LYC, Held PJ Growth rates in pediatric dialysis and renal transplant patients. Am J Kidney Dis 1997; 30: 193- 203
23. Fine RN Growth retardation in children with chronic renal insufficiency.
Nephron 1997; 76: 125-129
24. Hanna JD, Krieg RJ, Scheinman JI, Chan JCM Effects of uremia on growth in children. Semin Nephrol 1996; 16: 230-241
16. TECHNICAL ASPECTS OF HAEMODIALYSIS