Occurrence:
(1) suicide
(2) homicide
(3) iatrogenic accident
The scene investigation is important.
(1) If a syringe or IV bag is present then its contents should be analyzed.
(2) A vial of a concentrated potassium salt may be near the body.
(3) The presence of a suicide note may help to guide the investigation.
Other reasons to suspect potassium intoxication:
(1) The patient has a cardiac monitor in place that documents the arrhythmia.
(2) Someone is observed who looks suspicious.
(3) The presence of an unexplained venipuncture site.
In the absence of these findings, then the diagnosis may go unrecognized.
As detailed by Bertol et al, postmortem hemolysis can release intracellular potassium with a consequent hyperkalemia in postmortem serum. The authors found that the potassium concentration with a cardiac blood sample was much higher than that in peripheral samples.
Additional interventions:
(1) Collect the blood samples and separate the serum as soon as possible.
(2) Attempt to measure the degree of hemolysis in the serum sample. It is possible to correct the potassium concentration in a hemolyzed specimen if the hemolysis is not too severe (Jay and Provasek).
