From the Research
If there is a 4+ hemolysis noted on a BMP blood draw and the potassium is reported as 3.3 mmol/L, the actual potassium level is likely significantly lower than reported. Hemolysis causes the rupture of red blood cells, releasing intracellular potassium into the serum. Since red blood cells contain high concentrations of potassium (approximately 140 mmol/L), even minimal hemolysis can falsely elevate serum potassium measurements. With severe hemolysis (4+), the reported value of 3.3 mmol/L is almost certainly artificially elevated, meaning the patient's true potassium level could be dangerously low, potentially in the range of 2.5 mmol/L or lower.
This situation requires immediate clinical attention, including a repeat blood draw with careful collection technique to avoid hemolysis, and consideration of potassium replacement therapy if hypokalemia is confirmed. The healthcare provider should also monitor for symptoms of hypokalemia such as muscle weakness, cardiac arrhythmias, and abnormal ECG findings while awaiting accurate results. According to the most recent study on hemolysis index cut-offs 1, the impact of hemolysis on laboratory results, including potassium levels, can be significant and should be taken into account when interpreting results.
Key considerations in managing this patient include:
- Repeat blood draw with careful collection technique to avoid hemolysis
- Consideration of potassium replacement therapy if hypokalemia is confirmed
- Monitoring for symptoms of hypokalemia such as muscle weakness, cardiac arrhythmias, and abnormal ECG findings
- Awareness of the potential for hemolysis to falsely elevate serum potassium measurements, as noted in studies on the effects of hemolysis on laboratory results 2, 1.