Hemodialysis in Children

DR. KHALID AL-ALSHEIKH MDDirector of Nephrology & Dialysis Center

Consultant Pediatric NephrologistAFHSR, Khamis Mushayt, KSA

Introduction• In children with chronic kidney disease as GFR declines to less 30ml/min/1.73 m2 ( Stage 4 CKD)

• Preparation for renal replacement therapy are needed.

• The child and his family should be provided with information related to preemptive kidney transplantation

• Peritoneal dialysis

• Hemodialysis

• Renal replacement therapy is initiated in children with CKD stage 5 in some children with CKD stage 4

• Hemodialysis in children progress over last 20 years

• Morbidity of the session has decreased

• Technological progress, the availability of ESA and GH enhanced dialysis dose and increase quality of life

• Technically all children can underwent HD even infants

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Indication of RRT

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Incidence of ESRD in Children• ESRD in children is uncommon• Incidence in USA 14.8 / Million New Zealand 13.6 / million Japan 4 / million • The choice of RRT children:• ¼ underwent preemptive renal transplantation• ½ started in peritoneal dialysis• ¼ started in hemodialysis• Preemptive kidney transplantation which is performed prior to the

need of dialysis.• Renal transplantation is associated with better quality of life (Growth

and Development)

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Pediatric Dialysis in Saudi Arabia• HD Patients above 75 years and below 15 years of age 2012• Below 15 years 223 (1.8%)• 15-75 11739 (91.4%)• Above 75 878 (6.8%)

• PD patients adult and children 2012• Children 172/1327 = 13%• Adults 1155/1327 = 87%

SCOT Annual Report 2012 5

Epidemiology of chronic kidney disease in children

Pediatr Nephrol (2012) 27:363–373وJérôme Harambat & Karlijn J. van Stralen &Jon Jin Kim & E. Jane Tizard 6

Chronic Renal failure in children in Asir Region of Saudi Arabia

N. Alharbi Saudi Journal of Kidney Disease and Transplantation 1997 V8 Issue 3 pp 294-297

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Chronic Renal failure in children in Western Area of Saudi Arabia

Jameela A. Kari Saudi Journal of Kidney Disease and Transplantation year 2006 V17 Issue I pp 19-248

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Comparison of RRT Modalities in Children

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Choices of Dialysis• When preemptive transplantation is not an option

• the choices between the two forms of dialysis is generally dictated by patients age, technical, social, compliance issues and family preference.

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Principle of Vascular Access• Deliver adequate flow rate

• Has long use life

• Has low rate of complications• - Infection

• - Stenosis

• - Thrombosis

• - Aneurysm

• - Limb ischemia

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• The best is AVF

• USA - CVC used most often more than AVF and graft

- CVC 89% For children<13 Years

64% 13-19 YEARS

• Review of 2006 annual reports (NAPRTCS) reveals that in a family of pediatric patients 78.9% receiving HD have CVC as primary access.• AVF 12.3%• AVG 8.5%

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AV Fistula con’t.• PREFERRED SITE FOR AVF IN CHILDREN

1.Radiocephalic

2.Brachiocephalic

3.Brachiobasilic with or without transposition

• Alternative:

- Ulnar artery to basilic vein

- Femoral artery to saphenous vein

- Nondominant forearm

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Definite guidelines regarding minimal vessel sites don’t exist

• General consensus preferred of minimum 2.5 mm venous diameter

• Doppler U/S scanning or venography can provide information regarding adequate:

A) vessel size

B) venous stenosis

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AVGAVG Should be considered an option for HD access in children especially who

require replacement of native vessels to perform an adequate anastamosis

Alternative materials:

1.Saphenous vein

2.Bovine

3.Umbilical

4.Darcon

5.Polyurethane, cryopreserved femoral vein

6.Polytetrafluorethylene (PTFE) is most commonly used

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• One study compare bovine with PTFE graft demonstrated fewer complications with PTFE ones:• - Lower infections

• - Lower thrombosis

• - Easier to obtain and easier to repair

• Graft are most commonly placed in forearm between brachial artery & basilic to brachial vein.

• The thigh can be used femoral artery and saphenous to femoral vein in small children• -Higher infection rates been noted with thigh graft than with upper extremity grafts

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• Advantage of AVG1.Shorter time to use2.High primary potency rate3.Ease of technical creation

• Sheath et al reported creation of 24 AVF and 28 AVG respectively .• The most common site of AVG is the thigh -50% of patients

• Disadvantages of AVG1.Thrombosis2.Stenosis3.InfectionSheath et al permanent vascular access survival in children and adolescent with end stage renal disease 2002 Kidney Int 62:1864-1869

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• Ramage et al reported long term complications rate of AVF compare with AVG in retrospective study conducted over 20 years- Intervention rate 17.8% AVF compared to 33% of AVGReason of discontinuation of AVG were:1. Infection 20%2. Thrombosis 73%

• Chant et al evaluated dialysis adequacy , KT/V , URR, anemia management and albumin status based on vascular access. No difference between AVF & AVG• Possible Complications of graft1. Thrombosis2. Stenosis3. Infection 4.Steal syndrome

Ramage et al Vascular access survival in children and young adults receiving long term hemodilaysis 2005 AJKD 45:708-714Chant et al Comparison of vascular access type for pediatric HD with respect to urea clearance, anemia management, & serum

albumin conc. 2005 AJKD 45:303-30820

COMPARISON BETWEEN AVF & AVG

AVFAVGLower infectionHigher infection

Lower thrombosis rateHigher thrombosis rate

May take 3-6 months to matureCan be use within few weeks

Primary Failure rate is higherPrimary Failure is lower

Secondary Failure rate is lowerSecondary Failure rate is higher

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CENTRAL VENOUS CATHETER• Central venous catheter are the most commonly used vascular access in

children in north America data from USRDS 40% of children who were receiving chronic HD continued to use catheter• Data from ANZDATA 2008 showed the catheters were used exclusively below

10 years of age• NAPRTCS 2008• 78% catheters• 12% AVF• 7% AVG

• European Pediatric Dialysis Working Group• 60% catheters• 38% AVF• 2%AVG

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CENTRAL VENOUS CATHETERFirst choice in patient require urgent HD

2. Stage V CKD3. As abridge from a patient who is expected to receive planned transplant

4. Is training to transfer to PD- Advantage

- It can be used immediately- Disadvantage

1. Short life span2. Thrombosis3.Infection4. Malfunction5. Possible fibrin sheath formation

- Median survival times of CVC is 4 months – 10.6 months23

CENTRAL VENOUS CATHETER• Goldstein et al evaluated catheter survival time in 58

uncuffed & 22 cuffed CVCs

• Median survival time of uncuffed catheter is 31 days and cuffed catheter is 123 days

• 1 year survival of long term cuffed catheter 27%

• CVC in children whose vasculature is too small <10 kg, CVC may be the best temporary solution

• Goldstein et al 1997 HD catheter survival and complications in children and adolescent pediatric nephrology 11: 74-77

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•Two questions to be answered:

•What size of catheter to use?

•Where to put it?

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“SIZE MATTERS”!

• Pousielle’s law-

• Smaller diameters offer greater resistance to flow

• Longer lengths offer greater resistance to flow

• Decreasing the diameter by 1/5th is the same as doubling the length (roughly a 2 French size difference)

Q = ∆P rπ 4

8l

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Catheter Specifications

French

Size5781012

Flow Rate

(ml/min)?80-100150-200250-300285-330

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Catheter Specifications

French

Size5781012

Diameter

(mm)1.672.32.73.34.0

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Vascular Access• Central Venous catheter• Cuffed catheter• Uncuffed catheter

typeWeightsize

Uncuffed catheter dual lumen

Up to 208

20-3010

Above 3011.5

Tesio Catheter20-407

40-6010

Above 6012

Ash Split20-4010

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Complications of CVC• USRDS data have shown sepsis rate with CVCs approximate 80/100

patient as compared to 10/100 patient for AVF• Potential sequences of CVC include:

- Septic shock- Subacute bacterial endocarditis- Osteomyelitis- Epidural abscess• One study evaluated potential differences in infection rate based on

use of three agents for exit site care- 2% chlorhexidine found infection rate is 0.5%- 10% povidine iodine found infection rate is 2.5%- 70% alcohol found infection rate is 2.3%• Different antimicrobial catheter lock studies suggest that citrate is

ideal

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PROS AND CONS OF CENTRAL VENOUS CATHETER FOR HD IN CHILDREN

PROSCONS

Easily placedInfection rate high

Can be use immediatelyFailure rate and replacement rate high

Painless to the patientBlood flow rates are variable

Require little planning prior to placement

Permanent damage to central venous system (stenosis/thrombosis)

Easily removed if used as transitional access for future PD on transplant patients

Damage to central vessels can prohibit future AVF/AVG placement in ipsilateral extremity

No vascular StealPossible arrythmia

Decreased risk of high outpatient cardiac failure

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Monitoring of vascular access

• Goldstein et al described use of dilution technique on regular basis on pediatric patient population to date improve the life of access.

• Use of ultrasound 50% reduction in number of hospitalized patient.

• This further supported by NFK/K-DOQI guidelines for pediatric vascular access .

• Based on review of current literature the authors would propose the following as tools for ongoing monitoring of AVFs and AVGs.

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Access Monitoring

• 1. Inspection: the access should be assessed weekly through inspection, palpation, and auscultation by the nursing staff.• - With specific attention to arm swelling.

• - Prolonged bleeding after needle removal.

• - Change in thrills or bruits.

• -The nephrologist should inspect the access at each physical examination.

• 2. Surveillance ↓KT/V or URR. Determination of access recirculation should be documented on a monthly basis.• Ultrasound dilution/month if not available do Doppler U/S /month.

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Access Monitoring

• 3. Referral: Fistulogram with possible angioplasty if:- Inadequate blood flow comprising adequacy.

- Elevate access recirculation >20% after needle connection.

- Corrected access flow less than 650ml/min/1.73m2 by U/S dilution.

- Consistent abnormality on Doppler U/S.

-Pseudoaneurysm has formed, rotation of puncture site can help minimize risk of pseudoaneurysm.

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Hemodialysis Prescription• Hemodialysis Equipment:

• Tubing

• Dialyzer

• Dialysis Machine

• Tubing:TubingPt. weightVenous (ml)Arterial (ml)Total

Mini Neonatal<6 kg21829

Neonatal6-12 kg221840

Pediatric>12 kg423072

Adult>30 kg7060132

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Types of Dialyzer• Dialyzer:• Types of Membrane• Blood volume capacity• Service area• UF coefficient• Clearance of various substances• Sterilization

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Hemodialysis Prescription• Types of Dialyzer• Low flux (KUF <10 ml/hr/mmHg)• High flux KUF 15-60 ml/mmHg• Hallow fiber (capillary)• Parallel Plate

• Types of Membranes • Unmodified cellulose low flux• Modified cellulose (Low & high flux)• Synthetic (low & high flux)

• Synthetic noncellulose membranes are more biocompatible, size of dialyzer shouldn’t exceed 75-100% of patient service area

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Selection of Dialyzer that can be used in childrenUF Coefficient

(ml/min/mmHg)Fill Volume

(ml)Surface Area

(m2)Dialyzer

9.5771.3Gambro Polyflux 14L

12.51031.7 Polyflux 17L

53811.1 Polyflux 11S

621021.4 Polyflux 14S

711211.7 Polyflux 17S

15170.2 2H (HF)

33520.6 6H (HF)

1.7280.4Fresenius F3

4.3420.7 F4 HPS

6.2631.0 F5 HPS

8.5821.3 F6 HPS

9.81021.6 F7 HPS

11.11141.8 F8 HPS

49691.1Xenium 110 (HF)

62781.3 130 (HF)

63911.5 150(HF)

801262.1 210(HF)

2.5350.5Baxter CA-50 (LF)

8.1651.1 FB 110GA

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Hemodialysis Prescription con’t.

• Dialysis Machine:• Precise control of UF, volumetric assessment• Capable of low blood flow speeds• Ability to use lines of varying blood volume•Measure removal of very small amount of fluids• Continuous blood volume monitoring

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Hemodialysis Prescription• Blood Flow rate • 1st session 90 ml/m2

2-3 ml/kg/min• Latter 5-7 ml/kg/min 150-200 ml/m2

• Dialysate: It compose• Treated water• Electrolytes Na 140 mmol/L, K 2-3 mmol/L. Cl 100-102 meq/L, HCO3

40 meq/L, Mg 1.5-2 meq/L, Ca 1.25-1.5 mmol/L• Acid Buffers• Glucose 100 g/L

• Dialysate Flow rate 2 times more than blood flow rate, standard 500 ml/min

• UF: Standard weight 1.5-2 % of BW/hr. not more than 5% BW/HD session

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Hemodialysis Prescription cont.• Anticoagulation• Heparin loading – 2000 IU/m2

20 IU/kg

10 IU/kg in infant• Maintenance – 400 IU/m2

10-20 IU/kg to be discontinued 30 minutes prior to the end of dialysis

aPTT 120-160 or more than 50% above baseline of ACT• Heparin lock: with concentrated heparin 50 U/kg/lumen for weight less than

10 kg• 1000 U/ml BW (10-20 kg)• 2500 U/ml BW>20 kg

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Hemodialysis Prescription Components

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Hemodialysis Adequacy• Hemodialysis adequacy: Minimum adequate dose of HD given

3/times/week to patient with Kr less than 2ml/min/173m2, spkt/v 1.2/dialysis • URR of 65%• Target dose HD 3 times/week• spkt/v 1.4/dialysis not including residual kidney function• URR 70% single port kt/v

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Methods of Measurement of Delivered Dose of Hemodialysis

Single-pool Kt/V calculated by Daugirdas II Formula• Equation I:• spKt/V = - In (C1/C0 – 0.008 x t) + (4 – 3.5 x C1/C0) x UF/W

• Equilibrated kt/V• Equation II:• estBUN = ([BUN15min – BUN30secs]/0.69) + BUN30secs

KDOQI Guidelines 2006Cherry Mammen, Goldstein White Standard kt/V threshold to accurately predict single pool kt/V target for children receiving thrice weekly maintenance HD. Nephrology Dialysis Transplant 2010

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Methods of Measurement of Delivered Dose of Hemodialysis

• Equation III:• cKt/V (Goldstein) = -1n (estBUN/CO – 0.008 x t)+ (4-3.5 x estBUN/C0) x UF/W

• Equation IV:

• stdKt/V = 168 * [1-exp[-eKt/V]/t]/

• [1 – exp [ - eKt/V]/spKt/V] + [168/(N * t) – 1]

• Equation V:

• URR = 100x(estBUN – BUN30secs)/ BUN30secs

• Equation VI:• %UFF = 100 – [(pre-treatment weight – post-treatment weight)/post-treatment

weight]

Cherry Mammen, Goldstein White Standard kt/V threshold to accurately predict single pool kt/V target for children receiving thrice weekly maintenance HD. Nephrology Dialysis Transplant 2010 46

Recommended Methods vs Treatment Type for 2-3 HD per week• For 2 or 3 dialysis Treatment per week• Single pool Kt/Vurea determined by:• Urea kinetic modeling• Simplified multivariable equation

• Equilibrated Kt/V (eKt/V)• Bloodless measurements of dialyzer clearance using ionic conductance or

dialysate urea monitoring URR• Double pool Kt/Vurea by formal kinetic modeling (used only for research

purposes)• Solute removal index (SRI) from dialysate collections

• For more frequent dialysis: a continuous equivalent of kidney clearance• Standard Kt/Vurea

• Normalized Kt/Vurea

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Maintaining Hemodialysis Adequacy

• Preservation of residual renal function• Aggressive Management of HTN• Avoidance of Excessive UF• Avoidance of potential insults to RRF (contrast,

medications, infection, volume, contraction)

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Lower Kt/V causes• If spKt/V is lower than expected:• Blood flow rate

• Duration of treatment

• Dialysate flow

• Dialyzer specification and KoA

• Intradialytic hypotension

• Undetected early termination of treatment

• Was the anticoagulation adequate?

• Was post dialysis blood sampling appropriate?

• Was the needle size and placement appropriate and optimal?

• Was the blood pump adequately calibrated?

• Was the blood pump segment wrong?

• Was parenteral nutrition infused during treatment?

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Practical example of hemodialysis adequacy

MonthWeight (kg)spKt/VnPCR

134.31.401.20

235.21.321.15

336.11.201.18

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Practical example of hemodialysis adequacy

MonthWeight (kg)spKt/VnPCR

134.31.401.20

235.21.320.90

336.11.200.65

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Practical example of hemodialysis adequacy

MonthWeight (kg)spKt/VnPCR

134.01.401.05

232.51.320.95

331.31.450.88

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Anemia Management in ESRD in children

• Hb 11-12 g/dl• Serum ferritin target level >100 mg/ml• Tsat >20% • Monthly (CBC & reticulocyte count) • Every 3/12 serum ferritin, serum Tsat and serum iron.• with change therapy CBC weekly for 6/52

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• Eryhtropoetin • Initial dosing of HD below 5 years 250-300 unit/kg/week)• Above 5 years 150-200 units/kg/week • Darbapoetin 0.45 – 0.75 mcg/kg/week• IF Hb above target level or increase by 1.3 g/dl in 2 weeks decrease

25% of ESA• IF Hb increase 1.6-2 g/dl isn’t achieved over 8 weeks increase ESA by

25%

• Iron• Iron dextran need test dose because of anaphylaxis• Iron gluconate, sucrose. No need for test dose

KDOQI Guidelines 200654

• Serum phosphorus

• Children 1-12 years 4-6 mg/dl (1.26-1.93 mmol/L)

• Children over 12 years – 3.5-5.5 mg/dl (1.13-1.78 mmol/L)

• Serum calcium

• 8.8-9.5 mg/dl

• 2.20-2.37 mmol/L

• Ca x phosphate products should be less than 5 mmol/L

• Total eliminated Ca should not exceed 2500 mg/day

• Metabolic acidosis HCO 22 mmol/L

Bone Mineral Management in ESRD

KDOQI Guidelines 2006 55

Bone Mineral Management in CKDCKD stageGFR Range

(ml/min/1.73 meter square)Target serum PTH

260-8935-70 PG/ml, 3.85-7.7 pmol/l

330-5935-70 pg/ml, 3.85-7.7 pmol/l

415-2970-110 pg /ml, 7.7-12.01 pmol/l

5<15 or dialysis200-300pg/ml, 22-33 pmol/l

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StageGFRCalcium, PO4, total CO2PTH, alkaline phosphatase

260-89At least yearlyAt least yearly

330-59At least every 6 monthsAt least every 6 months

415-29At least every 3 monthsAt least every 3 months

5<15 or dialysisAt least every monthAt least every 3 months

Bone Mineral Management in CKD

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Nutritional Status• Phosphorus – CKD 3 – 5 and 5D decrease dietary phosphate to 80% of DRI for age

when PTH above target range of CKD and phosphate exceed normal reference

• Protein – dietary protein 100-140 of daily protein requirement for CKD 3-5

• Carbohydrate: Normal carbohydrate compare to age match healthy child

• Vitamins – B1, B2, B3, B5, B6, B8, B12, vitamin C, A, K, folic acid, copper, zinc should be 100% of daily requirement

• Trace elements 100% if clinical evidence of deficiency

• Free water & Na supplementation should be consider for polyuric child.

• Na supplements should be consider for all infants in PD due to substantial loss even anuric and to be restricted for hypertensive child

• Potassium should be restricted for CKD 2-5

• Acidosis is to be corrected to HCO3 22 mmol/l

KDOQI Guidelines 200658

Nutritional Status• Growth

• Growth hormone CKD 2-5 for short stature or height /age <3rd centile persist for 3 months despite adequate nutritional treatment and correction of metabolic abnormalities

• Calories should be 100% maintaining its chronological age

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Complications During Hemodialysis• Disequilibrium symptoms – movement of water to brain cell by

osmosis due to sudden drop of urea in plasma• Presentation: Nausea, headache, dizziness and seizure, coma

• Treatment: Blood flow, dialyzer, duration of treatment

• Mannitol of infusion 1g/kg over 1 h

• 1st session 30% drop, increase 50%, target 70-75% urea reduction

• Ct/C0 = e –kt/V

• Ct urea after t minutes of dialysis

• C0 urea at initiation of dialysis

• K – specific dialyser urea clearance ml/min

• V = Patient urea volume of distribution

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Complications During Hemodialysis• Hypotension:

• Intravascular volume depletion due to slow refiling from extravascular space

• Use of dialysate Na lower than plasma

• Exchanging UF

• Impaired sympathetic activity

• Warm dialysate – vasodilation

• Splanching pooling of blood while eating during dialysis

• Use of antihypertensive medication on day of dialysis

• Treatment:

• NS 5 ml/kg

• Cessation of UF

• Reassessment of target eight daily fluid allowance review

• Separate UF from dialysis

• Na ramping

• Hct monitoring61

Complications During Hemodialysis• Intradialysis hemolysis

• Symptoms: Pain & nausea

• Presentation: Dark appearance to venous blood due to over heating, contamination, hypertonicity of dialysate, kinking of line, malfunctioning of pump

• Treatment: Stop dialysis, check potassium

• Urticaria: antihistamine or hydrocort

• Air embolism: rare as air detection will clamp the return line 1 ml/kg

• Symptoms: Seizure, coma, chest symptoms

• Treatment: Clamp lines, stop pump, put head down, give 100% oxygen

• Air may need to be aspirated from ventricles

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Complication Post-Dialysis• Malnutrition is common is children receiving hemodialysis.

The risk of death is reported:• 54% for each 1 g/dl fall in albumin• 57% reduced if serum albumin >4g/dl• 14% increased with each decrease of one height of

standard deviation score below normal at start of dialysis

• Neuropsychologial outcomes: One study showed children below 18 months have:• 42% neuropsychological impairment• 58% attend regular school

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Social & Psychological Issues

• Dialysis Unit

• Vacation

• School

• Economic status

• Transfer of Service

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Complication Post-Dialysis

• Renal osteodystrophy

• Cardiovascular Disease• Hypertension – in one case series 624 children in HD

79% of them was with hypertension and with 62% receiving antihypertensive medications• Left ventricular hypertrophy up to 80%

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Mortality• Mortality risk in children in dialysis is >30 times higher than age and gender match

normal children

• US 5 years survival of 2867 patient starting dialysis at age 1, 1-5, and >5 years was 60, 80, and 85%

• ANZATA- RRT 1963-2002 demonstrated a 10 years and 20 years survival 79% and 66%.

• Mortality is higher in children in dialysis and less post transplant as noted by ANZATA

• UK Network 10 fold higher risk of death in children on dialysis compared to those were transplanted

• Cause of Death is CVD 1000 fold higher in young adults on dialysis than age match normal

• USRDS – 22.5% of death due to CVD

• ANZATA 45% of death due to CVD

• Dutch 41% of death due to CVD 68

Mortality• Age at start of dialysis • NAPRTCS report lower survival for children who begin

HD before 1 year of age with survival rate of 82, 73 63% at 1, 2, 3 years after initiation of dialysis.• Comparison of survival between Hemodialysis and PD• Italian registry showed no difference between 5-15

years but below 5 years who were most exclusively managed by PD had a poorer 5 years survival• USRDS showed no difference in 5 years survival

between PD and hemodialysis at any age

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Mortality

2013 USRDS Annual Data Report, Pediatric ESRD volume 2 70

Mortality

2013 USRDS Annual Data Report, Pediatric ESRD volume 2 71

Mortality

2013 USRDS Annual Data Report, Pediatric ESRD volume 2 72

Mortality

2013 USRDS Annual Data Report, Pediatric ESRD volume 273

Summary of Hemodialysis in Children• Although principles of hemodialysis are similar for adult and

children there are fundamental differences in technical aspect of procedures and complications

• Optimal care is provided by multidisciplinary team (Pediatric Nephrologist, skilled nurses, dietician, vascular access coordinator, vascular surgeon, radiologist, psychologist, and social worker)

• Good vascular access is essential for the success of hemodialysis

• Hemodialysis equipment must be modified for pediatric patient

• Long-term quality of life is lower in children on dialysis compared with normal healthy control and children receiving renal transplant

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