Differentiating Pseudohyperkalemia From True Hyperkalemia in a Patient With Chronic Lymphocytic Leukemia and Diverticulitis

Abstract

Acute changes in electrolyte levels can result in severe physiologic complications. Rapid treatment of abnormally elevated potassium levels is essential due to the increased risk of potentially fatal cardiac arrhythmias. However, there are a number of circumstances that can lead to falsely elevated serum potassium levels, including fist clenching during phlebotomy and hemolysis of hematocytes during laboratory processing. Here we present a case of an elderly woman with chronic lymphocytic leukemia who presented with lower left quadrant pain and hematochezia. Laboratory tests revealed an elevated serum potassium level (7.5 mmol/L) on initial testing, in the absence of hyperkalemia symptoms, EKG changes, and hemolysis of the blood specimen. Abdominal CT revealed inflammatory changes consistent with diverticulitis. She was treated with intravenous calcium, insulin, glucose, and bicarbonate for her hyperkalemia and admitted for treatment for diverticulitis. A subsequent serum potassium level (3.9 mmol/L) and discussion with the hospitalist suggested a diagnosis of leukolysis-induced pseudohyperkalemia, and further treatment of hyperkalemia was halted. This case serves to remind current and future physicians about the importance of maintaining clinical suspicion and clarifying unexpected laboratory readings when the clinical picture and results do not completely align.

Pseudohyperkalemia Associated With Leukemia

“…These EKG changes may or may not occur in order. Hence, if any of these changes are present, it should increase the suspicion for the cardiac involvement of hyperkalemia [ 2 ]. In situations where there is a slow rise in potassium, for example, in a patient with end-stage renal disease, it may result in the development of cardiac tolerance to the persistent high potassium in the system, which could present with unremarkable EKG findings.…”

“…It is also thought that there may be leakage of potassium from fragile white blood cells in patients with leukemia, leading to falsely elevated potassium. This is theorized to occur due to a lack of energy to maintain sodium/ potassium adenosine triphosphatase activity for the collected large number of white cells in-vitro, resulting in the release of potassium contributing to false hyperkalemia [ 2 , 5 , 7 - 8 ]. Another proposed mechanism is that the heparin in the collection tube causes damage to the membranes of the brittle malignant cells [ 8 ].…”

Pseudohyperkalemia and the Need for Imperative Caution With the Newly Introduced Potent Potassium Binders: Two Cases

“…However, before pseudohyperkalemia was diagnosed, we had treated the patient in the hospital with over one week of the new potassium binder, sodium zirconium cyclosilicate, with monitoring of only serum potassium at the time [6]. The dangers of erroneously treating pseudohyperkalemia include an inappropriate decrease in actual serum potassium levels, which may lead to arrhythmias and other adverse cardiovascular complications [8][9][10][11]. Anti-hyperkalemic treatment of patients without true hyperkalemia can produce iatrogenic hypokalemia, which can be fatal [9].…”

Lėtinių Ligų Sukeliama Hiperkalemija Ir Jos Valdymas

“…Daugeliu atvejų SPS hiperkalemija nustatoma atsitiktinai, atliekant laboratorinius elektrolitų matavimus arba arterinių kraujo dujų tyrimus. Pacientams, neturintiems hiperkalemijos rizikos veiksnių, reikia apsvarstyti pseudohiperkalemiją [25]. Hiperkalemija pagal K + kiekį serume gali būti skirstoma į lengvą (5,5-6,5 mmol/l), vidutinio sunkumo (6,5-7,5 mmol/l) bei sunkią (> 7,5 mmol/l).…”

“…Atliekant laboratorinius kraujo tyrimus K + koncentracijai įvertinti, kyla sunkumų: kraujo tyrimų rezultatų kartais tenka laukti keletą valandų ar net dienų, todėl esant ūmiai hiperkalemijai, nesiimama skubaus gydymo [39], o dėl klaidų tiriant mėginius laboratorijoje [40], mechaninių pažaidų mėginio paėmimo pro-cese, netaisyklingai paimtame mėginyje (po intraveniškai skirtų K + preparatų) stebima pseudohiperkalemija [41], kuri ne visada teisingai diferencijuojama nuo hiperkalemijos [42].…”