Low-shear red blood cell oxygen transport effectiveness is adversely affected by transfusion and further worsened by deoxygenation in sickle cell disease patients on chronic transfusion therapy.
Transfusion
; 53(2): 297-305, 2013 Feb.
Article
en En
| MEDLINE
| ID: mdl-22882132
ABSTRACT
BACKGROUND:
Simple chronic transfusion therapy (CTT) is a mainstay for stroke prophylaxis in sickle cell anemia, but its effects on hemodynamics are poorly characterized. Transfusion improves oxygen-carrying capacity, reducing demands for high cardiac output. While transfusion decreases factors associated with vasoocclusion, including percent hemoglobin (Hb)S, reticulocyte count, and circulating cell-free Hb, it increases blood viscosity, which reduces microvascular flow. The hematocrit-to-viscosity ratio (HVR) is an index of red blood cell oxygen transport effectiveness that varies with shear stress and balances the benefits of improved oxygen capacity to viscosity-mediated impairment of microvascular flow. We hypothesized that transfusion would improve HVR at high shear despite increased blood viscosity, but would decrease HVR at low shear. STUDY DESIGN ANDMETHODS:
To test this hypothesis, we examined oxygenated and deoxygenated blood samples from 15 sickle cell patients on CTT immediately before transfusion and again 12 to 120 hours after transfusion.RESULTS:
Comparable changes in Hb, hematocrit (Hct), reticulocyte count, and HbS with transfusion were observed in all subjects. Viscosity, Hct, and high-shear HVR increased with transfusion while low-shear HVR decreased significantly.CONCLUSION:
Decreased low-shear HVR suggests impaired oxygen transport to low-flow regions and may explain why some complications of sickle cell anemia are ameliorated by CTT and others may be made worse.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oxígeno
/
Transfusión de Eritrocitos
/
Eritrocitos
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Anemia de Células Falciformes
Tipo de estudio:
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Límite:
Adolescent
/
Adult
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Child
/
Female
/
Humans
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Male
Idioma:
En
Revista:
Transfusion
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos