Kintzel Polly E, Scott William L
Department of Pharmacy, MC 001, 100 Michigan St, NE, Grand Rapids, MI 49503, USA.
J Oncol Pharm Pract. 2012 Dec;18(4):432-5. doi: 10.1177/1078155211429885. Epub 2011 Dec 21.
Recognition of pseudohyperkalemia is essential to prevent medical mismanagement of erroneous hyperkalemia. The purpose of this case is to describe pseudohyperkalemia attributed to malignant leucocytosis in a patient with chronic lymphoblastic leukemia and tumor lysis syndrome. Methods for determination of pseudohyperkalemia are discussed.
A 75-year-old male with progressive chronic lymphoblastic leukemia was hospitalized for medical evaluation and chemotherapy administration. Notable laboratory findings included white blood cell count of 479 × 10(3) cells/µL (4.00 × 10(3) cells/µL-10.80 × 10(3) cells/µL) with 95% lymphocytes (20%-50%) and 5% blasts (zero) present in the differential, serum potassium 9.8 mM/L (3.4 mM/L-5.0 mM/L), uric acid of 11.8 mg/dL (3.5 mg/dL-8.0 mg/dL), serum creatinine 1.47 mg/dL (0.60 mg/dL-1.30 mg/dL), and lactate dehydrogenase of 2529 IU/L (100 IU/L-220 IU/L). The patient was anemic (Hb 7.6 g/dL (14.0 g/dL-18.0 g/dL)) and thrombocytopenic (17 × 10(3) platelets/μL (140 × 10(3) platelets/μL-400 × 10(3) platelets/μL)). There were no electrocardiographic findings indicating systemic hyperkalemia. Repeat analysis of the blood potassium level using a heparinized tube assayed immediately after specimen collection demonstrated a plasma potassium level 4.1 mM/L. Subsequent analysis of specimens using similar methodology demonstrated potassium results within the normal limits despite continued laboratory evidence of pseudohyperkalemia. Based on the patient's conscious and interactive condition, ECG findings, and normal plasma potassium level following immediate analysis, the diagnosis of pseudohyperkalemia was made. Laboratory findings of pseudohyperkalemia persisted throughout the period of leukocytosis.
This case describes pseudohyperkalemia attributed to malignant leucocytosis in a patient with chronic lymphoblastic leukemia (CLL). Practitioners should consider pseudohyperkalemia as the underlying cause of elevated potassium levels in patients with malignant leucocytosis who do not have signs or symptoms of systemic hyperkalemia.
识别假性高钾血症对于防止因错误的高钾血症而导致的医疗管理失误至关重要。本病例的目的是描述一名慢性淋巴细胞白血病和肿瘤溶解综合征患者中由恶性白细胞增多症引起的假性高钾血症。文中讨论了假性高钾血症的测定方法。
一名75岁男性，患有进展性慢性淋巴细胞白血病，因医学评估和化疗入院。显著的实验室检查结果包括白细胞计数为479×10³细胞/μL（4.00×10³细胞/μL - 10.80×10³细胞/μL），分类中淋巴细胞占95%（20% - 50%），原始细胞占5%（0），血清钾9.8 mM/L（3.4 mM/L - 5.0 mM/L），尿酸11.8 mg/dL（3.5 mg/dL - 8.0 mg/dL），血清肌酐1.47 mg/dL（0.60 mg/dL - 1.30 mg/dL），乳酸脱氢酶2529 IU/L（100 IU/L - 220 IU/L）。患者贫血（血红蛋白7.6 g/dL（14.0 g/dL - 18.0 g/dL））且血小板减少（17×10³血小板/μL（140×10³血小板/μL - 400×10³血小板/μL））。没有心电图表现提示全身性高钾血症。在标本采集后立即使用肝素化管对血钾水平进行重复分析，结果显示血浆钾水平为4.1 mM/L。随后使用类似方法对标本进行分析，尽管实验室持续有假性高钾血症的证据，但钾结果在正常范围内。基于患者清醒且有互动的状态、心电图表现以及立即分析后正常的血浆钾水平，做出了假性高钾血症的诊断。在白细胞增多期间，假性高钾血症的实验室检查结果持续存在。
本病例描述了一名慢性淋巴细胞白血病（CLL）患者中由恶性白细胞增多症引起的假性高钾血症。对于没有全身性高钾血症体征或症状的恶性白细胞增多症患者，从业者应考虑假性高钾血症是血钾水平升高的潜在原因。
