The most frequent form of unstable hemoglobin. Autosomal dominant transmission of the mutation 98 (FG5) Val à Met of the chain ß of the hemoglobin.

This mutation results in:

-         instability of heme (Hb precipitates in red blood cells where it forms Heinz bodies) with chronic hemolysis: mild jaundice, vesicular lithiasis, splenomegaly

-         acute hemolysis can occur during an infection or the administration of sulfonamides

-         increased affinity of hemoglobin for O2 : P50 = 17.6 mmHg, and therefore  chronic relative tissue hypoxia; in addition, a modified light absorption  by Hb Köln causes a false low reading of SpO2

-         increased risk of thrombosis after splenectomy: the high erythropoietin concentration due to tissue hypoxia increases platelets count.

Anesthetic implications: 

complete blood count; falsely low pulse oximetry values with small response to FiO2 increase; if in doubt, make a sample of blood gases to measure PaO2.

References : 

-          Katoh R, Miyake T, Arai T. 
Unexpected low pulse oximeter readings in a boy with unstable hemoglogobin Köln. 
Anesthesiology 1994; 80: 472-4

-         Gottschalk A, Silverberg M. 
An unexptected finding with pulse oximetry in a patient with haemoglobin Köln. 
Anesthesiology 1994; 80: 474-6

-         Andrieu V, Dumonceau O, Grange M-J. 
Priapism in a patient with unstable hemoglobin : hemoglobin Köln. 
Am J Hematol 2003; 74: 73-4.

-        Brugger S, Santafé-Marti MD, Lakhal M.
Low SpO2 with normal SaO2 during general anesthesia: a case report.
A&A Case Reports 2017; 9: 197-7.

Updated: October 2017