Pseudohyperkalemia from a Pneumatic Tube Transport System: Case Report and Literature Review

Abstract

Objective To report a case of pseudohyperkalemia due to a pneumatic tube transport system. Case Summary A 75-year-old male presented to the emergency medicine department with chest pain and intermittent vision loss over the previous 2 days. Laboratory studies revealed a potassium value of 9.6 mEq/L and a white blood cell (WBC) count of 262 × 109/L. An electrocardiogram did not reveal changes consistent with hyperkalemia. Emergent treatment for the hyperkalemia was instituted. Repeat plasma potassium values obtained after treatment for the hyperkalemia remained significantly elevated. It was eventually recognized that the hyperkalemia was due to the combination of undiagnosed leukemia causing a significantly elevated WBC count and transport of the patient's specimen to the laboratory via a pneumatic tube transport system. Manual transport of the specimen to the laboratory repeatedly revealed normal or hypokalemic values. Discussion Hyperkalemia is a potentially fatal electrolyte abnormality that must be differentiated from pseudohyperkalemia. Pseudohyperkalemia is defined as a spurious elevation of potassium levels usually due to mechanical trauma during venipuncture resulting in hemolysis and release of potassium from the cellular elements of blood. Pneumatic tube transport systems should be listed in the scientific literature as another potential cause of pseudohyperkalemia, especially in patients with high WBC and/or platelet counts. Conclusion Pharmacists and other health care providers should be aware of pneumatic tube transport systems potentially causing pseudohyperkalemia, because regular treatments for hyperkalemia for this problem may cause patient harm.

The Role of Using Red-Topped - Non-Additive-Containing - Collecting Tube in Diagnosing Pseudohyperkalemia in Chronic Lymphocytic Leukemia

“…However, the etiology of cellular lysis had been stipulated to a multitude of factors that pertain more to the maneuvers upon acquiring the blood samples. The use of a pneumatic tube transport system for example is implicated in producing pseudohyperkalemia [ 2 ], the exposure of the blood samples to variant ambient temperature [ 3 ], and delayed processing which exhausts the available glucose to generate adenosine triphosphate (ATP), which fuels the Na/K pump maintaining the gradient across the cell membrane. ATP shortage and consequent pump failure will result in leakage of potassium out of the cell, resulting in pseudohyperkalemia [ 4 ].…”

Pseudo-Hyperkalemia and Thrombocytosis: Case Report

“…It should be differentiated from pseudo-hyperkalemia. The latter is defined as an elevation of potassium levels usually due to mechanical trauma during venipuncture, resulting in hemolysis and potassium releasing from the cellular elements of blood [1]. This is a subject not well known among scholars, with a search of the Virtual Health Library, using the keywords "pseudo-hyperkalemia", Medline (International Literature on Health Sciences) delivers only 93 scientific articles; in IBECS (Spanish Bibliographic Index of Health Sciences), there were no publications and Scielo (Scientific Electronic Library Online) met two publications in July this year.…”

“…After proper treatment, their patient has showed 5.6 and 7.6 mEq/L and no compatible ECG changes. The clinical team suspected then pseudo-hyperkalemia, and to confirm, two blood samples were sent for analysis using different types of transport, one by hand and other through routine pneumatic transport system of the hospital, revealed potassium values 3.4 and 7.8 mEq/L, respectively [1]. It is important to distinguish true hyperkalemia from pseudo-hyperkalemia, which is not well known among medical professionals and, as a result, may lead to treatment for hyperkalemia, with serious consequences for patients who do not have the condition.…”