[SP-192] Isovolemic partial red cell exchange in an Infant with Hypoplastic Left Heart Syndrome and
Hemoglobin SC Disease in preparation for Fontan Palliation
Patel J, Harahsheh A, Verdun N, Jonas R, Levy R, Ibla J
Children’s National Medical Center , Washington , DC, USA
Introduction: Patients with sickle cell (HbS) and sickle cell-hemoglobin C (HbSC) disease who require
cardiopulmonary bypass (CPB) must undergo a reduction in abnormal hemoglobin fractions to minimize
the risk of vaso-occlusive crisis. This report describes a method of partial red cell exchange transfusion
immediately before the institution of CPB using a mathematical formulation. The accuracy of this
technique was corroborated by hemoglobin assay.
Case: 23 month old, 12.7 kg male with sickle cellhemoglobin C (HbSC) disease and Hypoplastic Left
Heart syndrome (HLHS) who presented for Fontan procedure. Pre-Fontan hemoglobin assay showed Hb S
46.9%, Hb C 42.2%, and Hb F 10.9%. By using a standard dilution formula V1 x C1 = V2 x C2
(C=concentration, V=volume), the patient underwent a dilution strategy with partial red cell exchange
transfusion to decrease the Hb S+C fractions from 90% (C1) to 35% (C2). The bypass circuit was primed
to a total volume of 1400 ml (V2). This contained 339 ml PRBC, 318 ml FFP. The baseline volume (V1)
was calculated to be 544ml in order to achieve the desired goal Hb S+C of 35% (C2). Therefore the
patients estimated blood volume (75ml/kg) of 900ml was decreased by 350ml in order to achieve baseline
volume (V1) of 544ml. Following sternotomy and cannulation, the perfusion team used the venous
cannula to drain 350ml of blood. This blood was subsequently discarded. Hemodynamic stability was
maintained by replacement of intravascular volume with CPB prime. Following partial exchange
transfusion, full CPB was initiated and mild hypothermia to 32 degrees Celsius was used to minimize the
risk of vaso-occlusive crises. The procedure required a total bypass time of 75 minutes with a cross clamp
time of 35 minutes. The patient tolerated the procedure well, required no additional blood products during
perioperative period, and was discharged home on postoperative day 9.
Discussion: To our knowledge, this is the first report of a child with HbSC disease who has undergone
completion of single ventricle palliation with a Fontan procedure. In managing our case, we avoided
preoperative red cell transfusion and instead used partial red cell exchange upon initiation of CPB to
decrease abnormal hemoglobin isoforms. By utilizing the bypass circuit for exchange transfusion, we
eliminated the potential risks of pre-operative exchange transfusion such as dehydration, hypothermia,
infection, venipuncture associated stress. In addition, our strategy proved to be efficient by uniformly
decreasing all Hb isoforms and resulted in low sickle loads even at postoperative day 19 (Figure 1),
demonstrating that this techniques benefits extended well into the postoperative period.
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