Severe hypokalemia in internal medicine hospitalized patients

Jung, Hyun Chul; Lee, Soo Bong; Kwak, Ihm Soo; Rha, Ha Yeon

Abstract

BACKGROUND: Serum potassium level assessment is one of the commonly requested laboratory tests. Hypokalemia is defined as a serum potassium level of less than 3.5 mEq/L. It can be potentially life-threatening when severe, due to its association with cardiac arrhythmia and sudden deaths. The aim of our study is to determine the prevalence and to define clinical characteristics of severe hypokalemia in internal medicine hospitalized patients.
METHODS
From December 1999 to June 2000, the group with at least one recorded plasma potassium concentration of less than 3.0 mEq/L was selected in department of internal medicine, Pusan national university hospital. Routine records of age, sex and prevalence was collected. Severe hypokalemia is defined as a serum potassium concentration less than 2.6 mEq/L. This patients were retrospectively studied for discharge diagnosis, medications prescribed before and during hospital stay, hospital course and laboratory findings.
RESULTS
There were 7.52% (235/3124) with at least one recorded potassium level of less than 3.0 mEq/L. Severe hypokalemia were 75 patients (2.4%). It were more likely to be female, but statically insignificant. Of the 75 patients, 59 patients (77.3%) had hypokalemia during hospitalization. Gastrointestinal loss of potassium was only 13.8% of the patients. The main causes were combination of iatrogenic factors, including the adminstration of intravenous fluids with insufficient or no potassium, malnutrition, and several drugs. The discharge diagnosis included infection 20 patients (26.6%), malignancy 19 patients (25.3%), gastointestinal disorders 8 patients (10.6%). And each of cardiovascular, respiratory and renal disorders have 7 patients (9.3%). In-hospital mortality was 34.6% (26/75) in severe hypokalemia. Compared to the alive group, death group showed statically significant decrease in serum albumin concentration (p<0.05).
CONCLUSION
Severe hypokalemia is fatal electrolyte disorder. The most frequent cause of this lethal condition is drug therapy and intravenous fluids with insufficient or no potassium replacement. It can be prevented by regular potassium monitoring and appropriate potassium supplementation in risky hospitalized patients.