Pseudohyperkalemia can result from the use of small bore IVs, excessive tourniquet time, fist clenching and mechanical stress during collection. These factors may affect pediatric blood draws.
This was a 5 year retrospective analysis of patients 0-17 years. 187 patients had a hemolyzed sample that showed hyperkalemia. 145 children had repeat testing and only 3 children had true hyperkalemia (2%). All three of these patients had underlying conditions that would have raised suspicion for hyperkalemia (chronic renal failure and diabetic ketoacidosis). There were no abnormalities to the BUN or creatinine in the patients without hyperkalemia.
Bottom line: This small study suggests that it may not be necessary to obtain repeat blood samples for hyperkalemia in patients with normal BUN and creatinine. Larger studies are needed before bringing this into mainstream practice.
Kaila et al. Hyperkalemia in a Hemolyzed Sample in Pediatric Patients: Repeat or Do Not Repeat? Pediatric Emergency Care 2022; 00:00-00.