Pediatric Pearls Dialysis Prescriptions for Petite Patients

Elizabeth Harvey MD FRCPC

Disclosure Research funding from Fresenius Co-PI Clinical Baxter - PD supplies Fresenius - HD machines/supplies All clinical photos are used with express patient and/or parent consent

Children are NOT

small adults

AND Small adults are NOT children

But sometimes worlds collide

How does an adult nephrologist prescribe dialysis for a pediatric-sized adult?

Objectives • HD: To familiarize the learner with the range of

vascular access, blood lines and dialyzers used in pediatric patients which may be applicable to HD in a small adult

• PD: To review the principles of pediatric peritoneal dialysis prescriptions applicable for prescribing PD in a small adult

Hemodialysis

HD Requirements

Access Machine Extracorporeal Circuit Prescription

Extracorporeal circuit < 10-15% of blood volume

HD Requirements

Access Machine -pediatric software and lines for < 10.5 kg

Circuit Prescription

2008: < 10.5 kg

5008: ≥ 10.5 kg

ACCESS

One size does not fit all!

Acute (Groin) Access Weight Catheter < 5 kg 6.5 F GamCath 5 – 14 kg 8 F GamCath 15- 20 kg 10 F Quinton Mahurkar (12 cm) 21-39 kg 10 F Quinton Mahurkar (15 cm) ≥ 40 kg 11.5 F Quinton Mahurkar All are double lumen lines

Chronic Neck Access – Double Lumen IJ Lines

Weight (kg) Catheter < 5 8 F Medcomp Hemocath 5 - 19 10 F Medcomp 20 - 34 12 F Medcomp Pediatric Quinton Permcath ≥ 35 Palindrome Bioflow Duramax Adult Quinton Permcath

HD Requirements

Access Machine Extracorporeal Circuit Prescription

Dialyzer Priming Volume

(mls)

Surface area (m2)

kUF (ml/hr/

mmHg TMP)

Material

FX Paed 18 0.2 7 Helixone (polysulfone)

Polyflux 2H 17 0.2 15 Polymix

Dialyzer Priming Volume (mls)

Surface area (m2)

kUF (ml/hr/ mmHg TMP)

Material

FX 40 32 0.6 20 Helixone (polysulfone)

FX 50 53 1.0 33 “

FX 60 74 1.4 46 “

FX 600 97 1.5 52 “ FX 800 118 1.8 63 “ FX 1000 138 2.2 75 “

Dialyzer Priming Volume

(mls)

Surface area (m2)

kUF (ml/hr/m

mHg TMP)

Material

Polyflux 6H 52 0.6 33 Polymix

Revaclear 84 1.4 50 PAES/PVP

Revaclear 400

93 1.8 54 “

Blood Lines

Blood Lines - 2008 Line Volume (mls) Neonatal Arterial 7 + Venous 20 = 27 Pediatric BVM 73

Blood Lines – 5008 Line Volume (mls) Pediatric BVM 108 Adult BVM 136

Tego Connectors High flow needle free connectors Luer lock syringe or dialysis lines

• Reduced incidence of catheter related blood stream infections

• Connectors changed…. – Weekly for most – After 36 punctures (inpatients) – < 10 kg – twice weekly – > 4 sessions HD/week – twice weekly

Neonates 100 ml/kg

Infants and Children (1 mon-16y)

80 ml/kg

Older Children (16y-18y)

70 ml/kg

Total Blood Volume Calculation

5.8 kg BSA 0.32

FX Paed (18) + Neonatal lines (27) = 45 mls (9.7%)

Access: 8F Medcomp

5 ml urea clearance

Machine: 2008

6 x 2 hrs (12 hrs/wk)

Kt/V: 0.8 URR: 50%

11.2 kg 0.5 m2 anephric

FX 40 (32) + Ped lines (73) = 105 mls (12 %)

Access: 10 F Medcomp

6 ml urea clearance

Machine: 2008 6 x 2.5 hrs (15 hrs/wk) Kt/V: 1.97 URR: 84%

17 kg BSA 0.67 High output

FX 40 (32) + Ped lines (108) = 140 mls (10 %)

Access: 10 F Medcomp

5 ml urea clearance (85 ml/min)

Machine: 5008

3 x 3 hrs (9 hrs/wk) Kt/V: -- URR: 82%

17.2 kg BSA 0.68

Polyflux 6H (52) + Ped lines (108) = 160 ml (12%)

Access: 10F Medcomp

HD: 6 ml urea clearance (100 ml/min)

Machine: 5008 4x 2.5 hrs (10 hrs/wk) Kt/V: 1.11 URR: 64%

32.2 kg BSA 1.11 m2

FX 60 (74) + Ped lines (108) = 182 mls (7 %) (1.4 m2 dialyzer)

Access: 12 F Medcomp

HDF: 6 ml urea clearance (190 ml/min)

Machine: 5008

3 x 4 hrs (12 hrs/wk) Kt/V: 1.69 URR: 76%

60.6 kg BSA 1.65

FX 60 (74) + adult lines (136) = 210 ml (4.3%)

Access: Bioflow Duramax

3 ml clearance (180 ml/min)

Machine: 5008 Dialysate 300 ml/min

Nocturnal 6 x 7 hrs (42 hrs/wk) Kt/V: 2.41

“Adequacy” 2006 KDOQI guidelines: •8.3.1 Children should receive at least the delivered dialysis dose as recommended for the adult population. (A) •8.3.2 For younger pediatric patients, prescription of higher dialysis doses and higher protein intakes at 150% of the recommended nutrient intake for age may be important. (B)

2015 KDOQI guideline • spKT/V 1.4 per session for 3 times per week (minimum 1.2 delivered) • Standard Kt/V 2.3 volumes per week for other dialysis schedules • Smaller patients especially women and children are at risk of

underdialysis

Surface normalization of Kt/V

Surface Area Normalized Kt/V in children

• 34 children in 2 centers • 3x/wk dialysis • Majority of younger children

did not achieve SAN-stdKt/V of 2.45

• Modelling showed need for > 8 hr sessions for thrice weekly

Summary 1. Hemodialysis circuits and access can

easily be adapted for small adults using guidelines from pediatric centers

2. Small adults are at risk for underdialysis with conventional treatments - Consider surface normalized markers of “dialysis adequacy”

Peritoneal Dialysis

PD Considerations

Access Modality – CAPD, APD Solutions Prescription • Dwell volume • Dwell duration

Access • Intraperitoneal configuration

• Straight • Coiled • Toronto western

• Subcutaneous configuration • Swan neck • Straight • # Cuffs

• Single • Double

Access Coil Catheter Catheter

Volume (mls)

Neonatal 1.7

Pediatric 2.3

Adult 3.6

+ single cuff neonatal catheter

Inguinal Hernias

• Search for hernias and repair them at catheter insertion in male infants and young children

• Highest frequency of inguinal hernias in first year of life

• Patent processus vaginalis – 80-90% newborns – 70% 3 months – 50% 1 yr – 20% adulthood

Hernias develop early in PD patients: 56% by 3 months 88% by 6 months

Photo courtesy of Dr Armando Lorenzo

Technical issues

• Insufficient muscle to completely bury the proximal cuff

Photos courtesy of Dr Armando Lorenzo

Tisseal used to create a water tight seal • seen during

catheter removal

Technical issues • Exit site must be sited away from

ostomies such as vesicostomies, g-tubes and colostomies, and out of the diaper area

Photos courtesy of Dr Armando Lorenzo

Distal Cuff Extrusion

• Single cuff catheter preferred in infants < 3 kg or cachectic patients

Distal cuff should be 2 cm from the exit site similar to adults

Access Complications

21 cm

Presternal Catheter

• Exit site should be easily visible and should not interfere with movement

• Avoid beltline

• Diapered or obese patients • Gastrostomies,vesicostomies • Recurrent ESI

Swan Neck Presternal Catheter

Sieniawska 1993

2 of 11 catheters disconnected at the internal connector at 7 and 33 months

Modality CAPD vs APD

Children • APD choice driven by:

• parent preference - attendance at work and school

• patient peritoneal transport characteristics • adapting adult equipment to children

Adults • CAPD vs APD

• Driven by patient preference/lifestyle

Solutions • Solutions will vary by

• Buffer type and concentration (35-40 mmol/L) • Bicarb • Bicarb/lactate • Lactate

• Calcium • 1.25 • 1.62 • 1.75

• pH • 5.2 – 7.4

• Magnesium • 0.25 - 0.5

Physioneal™ Dianeal™ Ca 1.25 Dianeal™ Ca 1.67 Balance™

Dwell volume considerations

• Impact of dwell volume on – Peritoneal solute transport – Intraperitoneal pressure – Ultrafiltration

Peritoneal Equilibration Test (PET)

Published by Twardowski et al in 1987 • Characterized the solute transport

characteristics of the peritoneal membrane

Twardowski et all PDI 1987

PET in Children

Geary et al KI 1992

PET in 32 children age: 0.8 – 17.8 yrs dwell volume: 32 ± 5 ml 70% children were high or high average transporters compared to adults, especially younger patients

Surface area adjusted PET in Children

PET repeated in 95 children - 0.1 – 19.5 years - dwell volume standardized to 1100 ml/m2 - results similar to that seen in adults

Warady et al JASN 1996

1880’s • Peritoneal SA is proportional to BSA • Infants peritoneal SA area per unit body

weight is double that of an adult

Underfilling of the peritoneum by scaling dwell volumes to weight creates an iatrogenic rapid transport state

Dwell volume considerations • Intraperitoneal pressure (IPP) is linearly related to exchange volume •IPP is related to position

– Lowest supine – Highest sitting – Intermediate standing

•Maximum tolerated pressure is 18 cm water in children and adults

Intraperitoneal Pressure (IPP) Measurement

• Patient perception of fill volume is subjective and not possible to determine in infants and small children

• IPP measurement

pioneered by Michel Fischbach

– Mid axillary line – Inspiration and expiration

Fischbach et al Ped Neph 2003

Intraperitoneal Pressure (IPP) Measurement

17 patients (1mo-15 yrs); 255 measurements

Fischbach et al Ped Neph 2003

• 1500 ml/m2 (2.66 L/1.73m2) = peak mass transfer area coefficient

• Adult volumes 1400-1600 ml/m2

(Keshaviah JASN 1994)

Consequences of large dwell volumes

• Symptoms • pain/discomfort • Respiratory compromise • ? Hernias

• Reduced ultrafiltration • IPP increases 3.76-6.11 cm H2O per litre of IP volume in recumbent

adults • Fluid absorption of 31-36 ml/hr/cm H2O increase in IPP • Higher glucose to achieve UF with high IPP

• Reduced phosphate removal

Icodextrin Day dwell

Dwell volume and icodextrin efficacy in children

Rousso et al, Ped Neph 2015

Icodextrin allergy

APD considerations Duration of treatment • infants 12-15 hrs • School age children 10 hrs • Some teenagers 8 hrs if residual renal function Number of cycles and average dwell time • Determined by peritoneal transport characteristics • Ultrafiltration requirements

• Usual dwell is 50-70 minutes Dwell volume • < 2 yrs: 800 ml/m2 • > 2 yrs: 1100-1400 ml/m2

Fischbach et al Ped Neph 2003

APD considerations Cycle length • Apex time = crossing of D/P urea

and D/D0 glucose • Dwell time for UF

• Phosphate purification time (PPT) • D/P Phosphate 0.6 • Dwell time for phosphate

removal • PPT is 3-4 times the Apex time

Fischbach et al PDI 1996, 16 (Suppl 1); S557-60

Adapted APD Adapted PD • small volume, short exchanges

favour UF • Large volume, long exchanges

favour solute removal • Sleep Safe Harmony cycler

Fischbach et al Advances in PD 2014, Vol 30; 94-7

PD Prescriptions

Ht 85.5 cm Wt 12.2 kg BSA 0.54 m2

CCPD: Home Choice 12 cycles in 14 hrs Nocturnal fill: 500 ml (925 ml/m2) Average cycle time: 59 min Day dwell: 0

PD Prescriptions

Ht 137.9 cm Wt 27.6 kg BSA 1.03 m2

CCPD: Home Choice Cycler 7 cycles in 10 hrs Average dwell time: 69 min Nocturnal fill: 1200 ml (1165 ml/m2) Day dwell: 600 ml Icodextrin (582 ml/m2)

PD Prescription

Pediatric PD prescription principles can assist with individualization of a PD Rx for small adults

Slide Number 1DisclosureChildren are NOT �small adults�Slide Number 4But sometimes worlds collideObjectivesSlide Number 7HD RequirementsHD RequirementsACCESSAcute (Groin) AccessChronic Neck Access – Double Lumen IJ LinesHD RequirementsSlide Number 14Slide Number 15Slide Number 16Slide Number 17Blood LinesBlood Lines - 2008Tego ConnectorsSlide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27“Adequacy”Surface normalization of Kt/VSurface Area Normalized Kt/V in childrenSummarySlide Number 32PD ConsiderationsAccessAccessInguinal HerniasTechnical issuesTechnical issuesDistal Cuff ExtrusionAccess ComplicationsPresternal CatheterModality �CAPD vs APDSolutionsDwell volume considerationsPeritoneal Equilibration Test (PET)PET in ChildrenSurface area adjusted PET in ChildrenDwell volume considerationsIntraperitoneal Pressure (IPP) MeasurementIntraperitoneal Pressure (IPP) MeasurementConsequences of large dwell volumesIcodextrin Day dwellDwell volume and icodextrin efficacy in childrenIcodextrin allergyAPD considerationsAPD considerationsAdapted APDPD PrescriptionsPD PrescriptionsPD PrescriptionSlide Number 61