During the authors’ monitoring of the patient for TLS, comparison of repeat values for potassium showed a significant difference of about 2.7 mEq/L between samples transported manually and samples sent via pneumatic tube (Figure). Similar elevations of values have been described in other case reports. 1
Reverse pseudohyperkalemia is a phenomenon that should not be overlooked in the medical management of patients with CLL with leukocytosis, especially in asymptomatic chronic patients. Although initially the differences can be benign, as the tumor burden increases, the degree of falsely elevated potassium can increase to thresholds that lead to inappropriate management in an acute setting. To prevent mismanagement, the authors recommend placing precautionary flags with hospital laboratories so that if a patient with CLL has a high potassium draw, lab values are rechecked with hand-delivered samples. The authors hope that this case will highlight the importance of suspecting this diagnosis in patients with CLL and provide guidance on obtaining accurate labs to better manage these patients.
Author disclosures
The authors report no actual or potential conflicts of interest with regard to this article.
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