血小板增多症导致假性血钾升高9例

Thrombocytosis-induced 9 cases with pseudohyperkalemia

目的研究血小板增多症患者的临床特点,以提高临床医生对血小板增多症引起假性血钾升高这一现象的认识,避免误诊高钾血症或漏诊低钾血症。方法测定9例血小板增多症患者的血浆钾浓度及采取血样后即刻血清钾浓度,进行对比分析,选取其中1例患者血液样本,测定其放置2 h的血清钾浓度。同时测定7例血小板计数正常患者的血清钾及血浆钾浓度作对照观察。结果 9例血小板增多症患者血清钾及血浆钾浓度检测结果显示,血清钾水平均高于血浆钾。9例患者血小板计数在（431~2448）×10~9/L,血清钾与血浆钾浓度差在0.47~2.53 mmol/L,平均浓度差为1.35 mmol/L。3例患者血清钾检测显示有高钾血症,但血浆钾浓度在正常范围内,无高钾病因及临床表现,诊断为假性高钾血症;2例患者血清钾检测在正常范围内,但血浆钾浓度显示有低钾血症。9例患者平均血清钾浓度（5.34±0.70）mmol/L与平均血浆钾浓度（3.99±0.55）mmol/L比较,差异具有统计学意义（P〈0.05）。1例患者测定了即刻血浆钾及放置2 h的血清钾浓度,发现血清钾水平随标本放置时间的延长而升高。7例血小板计数正常患者血清钾及血浆钾浓度差在-0.31~0.24 mmol/L,平均浓度差为0.104 mmol/L。7例血小板计数正常患者平均血清钾浓度（3.76±0.38）mmol/L与平均血浆钾浓度（3.65±0.38）mmol/L比较,差异无统计学意义（P〉0.05）。结论对于血小板增多症的患者,血浆钾浓度更能反映体内真实血钾水平;标本应在采样后尽快送检;血小板计数正常的患者其血清钾与血浆钾浓度差别较小,不影响临床判断。

Objective To research clinical characteristics of pseudohyperkalemia patients, in order to improve knowledge in clinicians of thrombocytosis-induced pseudohyperkalemia, and to avoid misdiagnosed pseudohyperkalemia and missed diagnosis of hypokalemia. Methods Detection was made on plasma potassium concentration and immediate serum potassium concentration after blood sample collection in 9 patients with thrombocytosis for comparison. One patient’s blood sample was taken to detect its 2 h serum potassium concentration, along with comparative observation by serum potassium concentration and plasma potassium concentration in other 7 cases. Results Detection of serum potassium concentration and plasma potassium concentration in 9 cases showed higher serum potassium level than plasma potassium level. The 9 cases had blood platelet count as（431~2448）×10~9/L, concentration difference between serum potassium and plasma potassium as 0.47~2.53 mmol/L, and mean concentration difference as 1.35 mmol/L. There were 3 cases with hyperkalemia shown by serum potassium detection, along with normal level of plasma potassium. Due to their lack of pathogenesis and clinical manifestations of hyperkalemia, they were diagnosed as pseudohyperkalemia. There were 2 cases with normal serum potassium level, but their plasma potassium concentration showed hypokalemia. The difference of mean serum potassium concentration as（5.34±0.70） mmol/L and mean plasma potassium concentration as（3.99±0.55） mmol/L in 9 cases had statistical significance（P〈0.05）. Detection of immediate plasma potassium and 2 h serum potassium concentrations in 1 case showed increasing serum potassium levels along with sample storage period. Serum potassium and plasma potassium concentrations in 7 cases with normal blood platelet count ranged-0.31~0.24 mmol/L, with mean concentration difference as 0.104 mmol/L. There was no statistically significant difference between mean serum potassium concentration as（3.76±0.38） mmol/L and mean plasma potassium concentration as（3.65±0.38） mmol/L in 7 cases with normal blood platelet count（P〉0.05）. Conclusion Plasma potassium concentration in patients with thrombocytosis reveals precisely physical blood potassium level. Immediate detection is necessary after sample collection. Slight difference between serum potassium and plasma potassium in patients with normal blood platelet count shows no influence on clinical judgment.