Incidence, risk factors, and prognosis of hypokalemia in patients with normokalemia at hospital admission.

<strong>Background</strong> Hypokalemia (K+&lt;3.5 mmol/L) is a common electrolyte abnormality observed in 20% of hospitalized patients. Previous studies have often dealt with the symptoms of hypokalemia, its prevalence, and risk factors in hospitalized patients. Very few studies have dealt with hospital-induced hypokalemia. The aim of this study was to find the incidence, predisposing risk factors, and prognosis of patients developing hypokalemia in patients with normokalemia at admission. <strong>Materials and methods</strong> A prospective observational study was performed over a period of two months. Patients with at least two potassium values after admission and normal K values at admission were considered for inclusion. Clinical features, diagnoses, laboratory reports, and treatment details, including antibiotics, were noted. Incidence of hypokalemia was determined. Patients with and without hypokalemia were compared. <strong>Results</strong> A total of 653 patients were studied; 138 (21.1%) developed hypokalemia. Diabetes, ischemic heart disease, heart failure, chronic kidney disease, hypertension, chronic liver disease, and COPD were the most associated comorbidities. Urea, creatinine, transaminases, and neutrophilia at admission differed significantly between those with and without hypokalemia groups. Most patients developed mild hypokalemia (78.2%); moderate and severe hypokalemia developed in 19.5% and 2% of patients, respectively. Hypokalemia developed mostly on the second(22.4%) and third (24.6%) day of hospitalization. Antibiotics were used in 60% of patients, with 23% and 24.5% receiving one and two antibiotics, respectively. Only linezolid and metronidazole use were significant with regard to the patient’s second potassium value. The potassium values returned to normal within 2.5±1.9 days. Three patients subsequently developed hyperkalemia. <strong>Conclusion</strong> Patients admitted under General Medicine mostly developed mild hypokalemia, even if they had multiple risk factors for developing hypokalemia. Inpatient hypokalemia had an incidence of 21%. An overwhelming majority (~88%) had at least one risk factor. Hypokalemia was not attributed to causing mortality in any patient.

研究背景：低钾血症（hypokalemia，血清钾＜3.5 mmol/L）是一种常见的电解质异常，在住院患者中的发生率约为20%。既往研究多聚焦于住院患者低钾血症的症状、患病率及危险因素，极少有研究关注医源性低钾血症。本研究旨在探究入院时血钾水平正常的患者发生低钾血症的发生率、易感危险因素及预后情况。
材料与方法：本研究为一项为期2个月的前瞻性观察性研究。纳入标准为入院后至少完成2次血钾检测且入院时血钾水平正常的患者。记录患者的临床特征、诊断结果、实验室检查报告及包括抗生素在内的所有治疗细节，计算低钾血症的发生率，并对比发生与未发生低钾血症患者的临床差异。
研究结果：本研究共纳入653例患者，其中138例（21.1%）发生低钾血症。与低钾血症发生关联最为密切的合并症包括糖尿病、缺血性心脏病、心力衰竭、慢性肾脏病、高血压、慢性肝病及慢性阻塞性肺疾病（COPD）。入院时的尿素、肌酐、转氨酶水平及中性粒细胞增多情况在低钾血症组与非低钾血症组间存在显著差异。大多数患者表现为轻度低钾血症（78.2%），中度和重度低钾血症患者占比分别为19.5%和2%。低钾血症多发生于住院第2日（22.4%）和第3日（24.6%）。60%的患者使用了抗生素，其中23%和24.5%的患者分别接受1种和2种抗生素治疗。仅利奈唑胺（linezolid）与甲硝唑（metronidazole）的使用与患者第二次血钾检测结果存在显著相关性。患者的血钾水平可在2.5±1.9日内恢复至正常范围。另有3例患者后续出现高钾血症（hyperkalemia）。
研究结论：收入普通内科（General Medicine）的患者即使存在多项低钾血症易感危险因素，仍多表现为轻度低钾血症。住院相关性低钾血症的发生率为21%，约88%的患者存在至少1项易感危险因素。本研究未发现低钾血症导致患者死亡的案例。