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

Abstract

Background Hypokalemia (K+<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. Materials and methods 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. Results 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. Conclusion 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.