Manual flagging failed to identify pseudohyperkalemia in acute myeloid
leukemia: case report

Manual flagging failed to identify pseudohyperkalemia in acute myeloid
leukemia: case report

Pseudohyperkalemia, Acute myeloid leukemia, Pneumatic tube transport, Lab flagging, Automation, Case
report

Abstract
Background Pseudohyperkalemia is well known in acute or chronic lymphocytic leukemia, but it is very rare in acute
myeloid leukemia (AML). The lab flagging system for leukocytosis to prevent pseudohyperkalemia may not work.
Case presentation A 55 year-old white man with AML was sent to emergency department for transfusion due
to severe anemia. Blood test showed severe leukocytosis and elevated potassium. Repeated blood test showed
his potassium was even higher. Anti-hyperkalemic medical treatment was given. He was then diagnosed with
pseudohyperkalema.
Investigation I was repeatedly reassured that the lab’s manual flagging system for leukocytosis was the key
in reaching the correct diagnosis. My persistent inquiries, however, revealed that the flagging system was not
functioning in the care of this patient. It was clinicians’ suspicion of pseudohyperkalema that led to the correct
diagnosis, although the clinicians’ recommendation of obtaining a heparinized plasma for test did not play a role
because all blood samples were already heparinized. The cause of pseudohyperkalemia was pneumatic tube
transport. After this incident, our laboratory is investigating the options of using the Laboratory Information System to
automatically flag the results and Clinical Laboratory Scientists to make the chemistry team more aware of potentially
erroneous potassium results due to pseudohyperkalemia.
Conclusions Pseudohyperkalemia associated with leukocytosis still occurs. This is the first case of pneumatic
tube transport causing pseudohyperkalemia associated with AML. When significant leukocytosis, thrombocytosis,
hyperproteinemia, or hyperlipidemia is present, whole blood should be utilized for potassium measurements and
walked to the lab instead of sent by pneumatic tube transport. Even in a lab with a manual flagging system, there is
still room to improve by implementing an automatic flagging system.
Keywords Pseudohyperkalemia, Acute myeloid leukemia, Pneumatic tube transport, Lab flagging, Automation, Case
report
Summary
Despite an existing laboratory flagging system, pseudohyperkalemia still occurred in a patient with extreme
leukocytosis. The incident led to a plan to automate the flagging.

Yangming Cao1,2*

https://doi.org/10.1186/s12245-024-00734-x

2024

Peri Irawan

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