Case Study 1: Red Cell Exchange

Education Session VI: Pediatric Apheresis

Leon Su, MD

Section Chief, Transfusion Medicine and Apheresis

Disclosures

• None

Patient HM

• 8 year old female SCD

• History of CVA in 2012

• Hgb S levels well maintained on chronic tx(20-30%)

• Ferritins and Iron in liver (MRI quantification) elevated despite chelation therapy

• Began chronic exchange therapy in early 2015

When to consider outpatient red cell exchange(Sickle cell disease, non-acute)

• Stroke prophylaxis/iron overload prevention• ASFA Category II, Recommendation 1C

• Vaso-occlusive pain crises• ASFA Category III, Recommendation 2C

• Pre-Op management• ASFA Category III, Recommendation 2A

Schwartz et al. J. Clin Apheresis 28:145-284, 2013Kim et al. Blood 83(4):1136-1142, 1994

Exchange Transfusion Simple Transfusion

Reduced transfusional iron Iron overload more common

Unrestricted by baseline HCTwith ability to target end HCT

Restricted to lower baseline HCTs to avoid high viscosity

Multiple donor exposures Less donor exposure

Access Options• Peripheral access

– 18 gauge dialysis-type steel needles

– 18 to 20 gauge angiocaths

• AV fistula and grafts

• Central venous catheters– Tunneled and Nontunneled

• Ports (indicated for power injection)– Single and bilateral

– Dual lumen

Double lumen ports

• 9.5 Bard powerport: 40-50 mL/min

• 11.4 Angiodynamics dual lumen smart port: 50-60 mL/min

• Considerations when choosing port

– Previous history of clots and infections

– History of peripheral access

– Evaluation by apheresis nurses

– Appropriate size based on patient

“They looked into my mouth and into

my ears; they looked into my eyes

and touched my tummy. But, they never looked at

me.”(7 year old patient)

Preparing a child for port access: child life support resources

What is a Child Life Specialist?

• Assist children in managing/understanding healthcare experiences

• Assessment

• Play: therapeutic play, medical play, developmental play

• Preparation

• Coping strategies

• Pre-admission tours

• Educate

• End of Life/ Bereavement work

• Sibling support

• Back to school

• Supervise

Child Life Support

Initial access

Ready for exchange

Blood Product Selection

• HM is DcE/DcE with antibody to little e. • Requires C, K, Fy(a), Jk(b), S and little e negative blood

Institutional Guidelines• Type and screen 1-3 days prior to exchange• Rh and Kell matched if negative screen• Also Fy, Jk and S matched if positive screen• Hgb S negative, no irradiation unless other indication• < 14 days old• Communication with blood bank and blood provider

paramount to ensure availability of blood

Prime versus nonprime

• Extracorporeal volume (ECV)

• Blood warmer volume (BWV)

• 10-15% of TBV should not exceed ECV + BWV

• If not priming, intraprocedure HCT can be calculated

• Optia – Prime with saline/albumin during RBCX results in a mix of replacement fluid (RBCs) with saline/albumin in the return line to a HCT = patient

Monitoring Hgb S and procedure parameters

• Pre and post Hgb S levels

• Target pre procedure Hgb S levels below 30%

• HM fluctuates between 10-30% pre and post procedure

• Frequency start at every 4 weeks

• Typical FCR 40%

• AC infusion rate 1.1 with 15 mg/kg/hr Calcium Gluconate or AC infusion rate 0.8 with no calcium

• WB:AC ratio 15:1

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Pre HCT

Post HCT

0

100

200

300

400

500

600

700

800

900

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Ferritin

• Procedure 14 and 15 had frequency of 5 weeks before procedure

• Depletion performed with procedures 4, 12 and 13

• Minimizing iron gain– Lower end target HCT

– Combining with depletion

• End target HCT – what’s the right target?

0

50

100

150

200

250

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Iron (mg)

Adverse reactions

• HM tolerates procedures well and has not had any adverse events over her 1.5 year course

• Premedicated with Tylenol and Benadryl

• Other patients with hypotensive reactions and allergic reactions

– Managed with corticosteroids and fluid boluses, one patient with washed red cells

Summary

• HM continues to have good Hgb S control at 4 week interval RBCX

• Her Ferritins came down from the 1500s to the 400-600s with exchange and better compliance with iron chelation therapy.

• Plan is to keep at 4 week intervals which will hopefully help pre procedure HCTs stay >24% and allow for modest depletion with exchanges

• May require splenectomy down the road

Thank you!