Very rare. Abnormality of hemoglobin due to a mutation of the HBA2 gene (codon 136: GTC > GCC with substitution of leucine with proline) (16p13.3) causing instability of the α chain of hemoglobin. This mutation results in a modification of the structure of HbA: kinking in the middle of the X helix. This results in chronic hemolytic anemia with presence of Heinz bodies (aggregates of hemoglobin) in red blood cells. The severity of hemolytic anemia is variable.

Anesthetic implications:

chronic hemolytic anemia; falsely low value of SpO2 (pulseoxymetry): less than 90% value even in presence of high FIO2

The importance of desaturation depends on the circulating level of Hb Bibba: desaturation is inversely proportional to the severity of anemia.

References :

-        Cirenei C, Veyckemans F, Barbati M, Bert D, Laffargue-Vetter A, Richart P.
Fluctuating pulse oximetry readings in an adolescent with Hemoglobin Bibba: a case report.
A&A Practice, 2018; 11:52-3

Updated: July 2018