SCD-Ery.babawith Luhanga and Neil

8/14/2019 SCD-Ery.babawith Luhanga and Neil

http://slidepdf.com/reader/full/scd-erybabawith-luhanga-and-neil 1/18

HCK

Paediatric Red Blood CellExchange

IntroductionBaba Inusa

Adult PerspectiveNeil Westerdale

Paediatric and adolescentsLuhanga Musumadi

24th September, 2008



HCK

Indications for Transfusion in

Sickle Cell Disease

2. sickling by lowering Hb S conc.

Prevention of recurrent stroke or

first clinical stroke (abnormal TCD)

Chronic debilitating painful crises

Chronic lung disease with arterial

hypoxaemia



HCK

Complications of Long-term

Transfusion

Transfusional Iron Overload- Delayed growth and sexual maturation

due to endocrine disturbances

- Diabetes mellitus

- Cirrhosis

- Cardiac arrhythmias and heart failure- Death >15-20 yr. of chronic transfusion



HCK

Complications of Transfusion

AlloimmunizationTransfusion-transmitted Infections

Transfusional Iron Overload



HCK



HCK

Risk of Recurrent Stroke

If presented within 24 hours of symptomonset, patients who received simpletransfusion had a five times greater risk ofrecurrent stroke when compared tochildren who received exchangetransfusion therapy (95% CI 1.3, 18.6).

No difference in odds of recurrent strokewas found for any type of treatment after24 hours of symptoms.



HCK

Multivariate analysis

Risk of recurrent stroke was 8times higher for patientsreceiving simple transfusion

within 24 hours of symptomsand in the absence of anantecedent medical event (95%CI 1.6, 38.8).



HCK

Time from first stroke to second stroke (years after stroke)

2520151050

C u m

u l a t i v e S t r o k e - F r e e I n t e r v a l

1.0

.8

.6

.4

.2

0.0

Type of Transfusioin

exchange transfusion

exchange transfusion

-censored

simple transfusion

simple transfusion-censored

Risk of Recurrent Stroke(n= 81)



HCK

TransfusionPre – Post –

HAEMATOCRIT (%)

B L O O D V I S C

O S I T Y

( c P )

2

3

10 20 30 40 50

4

5

6

7

Pathophysiology

Jan et al , Transfusion,1982, 22(1):19



HCK

8 8.5 9 9.5 10 10.5 11 11.5

90

80

100

110

120

130

140

150

Hb [g/dL]

C B F [ m L / 1 0 0

g / m i n ]

5 10 15 20 25 30 35 40 45 50 5580

90

100

110

120

130

140

150

C B F [ m L / 1

0 0 g / m i n ]

HbS [%]

Why would exchange transfusion be better thansimple transfusions for decreased risk of strokes?

Hurlet-Jensen et al , Stroke, 1982, 25(8):1690



HCK

Reduce or prevent iron accumulation

while preventing

recurrent stroke in patients with sickle

cell

disease and stroke

ERYTHROCYTAPHAERESIS



HCK

Rationale for Erythrocytaphaeresis

in Reducing Iron Overload

With exchange transfusion, RBCs from patients

are removed while donor RBCs are being given,resulting in fewer RBCs to contribute iron to the

body in comparison with simple transfusion.



HCK

Goals

x Removal of patient’s RBCs:

x Exchange patient’s abnormal RBCs

with normal RBCs:

Erythrocytaphaeresis

- Reduction of blood viscosity in polycythemia

- Reduction of excessive iron in non-anemic

hemochromatosis

- Hereditary or acquired RBC disorders



HCK

Erythrocytaphaeresis in SCD

As a treatment or prevention of

acute complications:q Acute chest syndromeq Strokeq Pre-op (when Hb > 10 g/dl)

As a long-term transfusion therapy



HCK

Long-Term Erythrocytaphaeresis

Sickle Cell Dis with Stroke

< first 3 yr > 3 yr

Pre-Ex Hb S < 30% < 50%*End Hb S (%) 12 - 15 20 - 25

End Hct (%) 27 - 36 27 - 36

• Patient must be clinically and neurologically

stable before raising the target Hb S to <50%

from <30%.



HCK

Acute Erythrocytaphaeresis

AdvantagesxRapid in Hct level without

volume overloadx Rapid Hb S level without

substantially the Hct level

x rate of transfusional iron loading

x Duration of procedure shorter



HCK

Long-term

Erythrocytaphaeresis in SCDAdvantages

Reduces the transfusional iron accumulation- Delays onset of transfusional iron-induced

organ damage

- Delays initiation of iron chelation therapy

- Prevents the need for iron chelation therapy



HCK

Disadvantages

x Problem with venous accessx Increased blood usage x Increased no. of donor exposure

x Increased cost for the proc. (?)

x Universally not available

ERYTHROCYTAPHAERESIS

Documents

SCD-Ery.babawith Luhanga and Neil