Understanding Hypokalemia in Acute Patients: Prevalence, Causes, and Impact Factors

Introduction

Stroke is a common chronic disease and the second leading cause of death worldwide. It has a high rate of occurrence, recurrence, disability, mortality, and economic burden. Approximately 26 million people are diagnosed with stroke each year, with Acute Ischemic Stroke (AIS) representing 60%-80% of these cases. AIS occurs due to interrupted blood flow to the brain, leading to damage and significant rates of mortality and disability. Patients may experience complications such as cognitive impairment, swallowing difficulties, and malnutrition. Thus, AIS requires significant attention.

Potassium (K+) is an important electrolyte in the body. It helps maintain cellular balance, supports muscle contraction, regulates fluid and acid-base status, aids nerve conduction, and participates in energy metabolism and enzymatic activities. Hypokalemia, a condition defined by low potassium levels, can occur due to excessive potassium loss, abnormal distribution, inadequate intake, or other factors. It often results from increased renal excretion, gastrointestinal loss, or conditions affecting absorption.

Study Design

The study used convenience sampling to include patients diagnosed with acute ischemic stroke at a Class III Grade A hospital in Wuxi from January 2021 to December 2022.

Setting and Participants

Participants met criteria including: diagnosis of acute ischemic stroke confirmed by imaging, age 18 or older, within 7 days of onset, ineligible or refusing thrombolysis, and providing informed consent. Exclusion criteria included severe mental illness, cancer, profound kidney disease, acute gastrointestinal disease, severe organ damage, unstable hemodynamics, and diuretic use.

Sample Size

To ensure statistical power, the sample size was calculated as 10 to 15 times the number of independent variables, totaling 996 cases after accounting for attrition.

Measurements

Demographic data included gender, age, weight, height, BMI, blood pressure, smoking and drinking history, and medical history. Laboratory tests included WBC, RBC, hemoglobin, platelet count, glucose, cholesterol, triglycerides, serum sodium, potassium, blood urea nitrogen, and creatinine levels. Additional assessments covered neurological function, daily living activities, frailty, nutritional risk, and swallowing ability.

Data Collection

Demographic data were retrieved from medical records. Serum potassium levels were measured within 24 hours of hospitalization. Hypokalemia was defined as potassium levels below 3.5 mmol/L. Investigators followed structured protocols for surveys, ensuring confidentiality and informed consent. Out of 1050 questionnaires, 996 were completed, resulting in a recovery rate of 94.9%.

Statistical Analysis

Descriptive statistics were used for data presentation. Mean ± standard deviation represented normally distributed data, while skewed data were expressed as median with interquartile ranges. Patients were categorized into hypokalemia and non-hypokalemia groups, with independent samples tested using t-tests and χ2 tests. Logistic regression identified factors influencing hypokalemia.

Results

A total of 996 patients were included, with 20.6% exhibiting hypokalemia. Stroke severity varied, with classification based on the NIH Stroke Scale. Significant differences were found in patient characteristics affecting potassium levels.

Discussion

Few studies have examined hypokalemia in acute ischemic stroke. Hypokalemia can increase the risk of cardiac arrhythmias and may cause muscle weakness and fatigue. This study identified factors influencing hypokalemia, including age, hypertension, frailty, neurological status, swallowing ability, platelet count, and blood urea levels.

Research suggests correlations between hypokalemia and factors such as hypertension. Diuretics often increase potassium loss. Patients with hypertension may also experience hormonal changes leading to potassium depletion. In frail patients, malnutrition can reduce potassium intake and absorption.

The study also noted a relationship between neurological function and hypokalemia. Higher NIHSS scores indicated a greater likelihood of hypokalemia. The study observed that swallowing difficulties could affect dietary intake, thus contributing to potassium imbalance. Moreover, the correlation between higher blood urea levels and lower rates of hypokalemia may demonstrate renal function dynamics during acute stress.

Conclusion

This study highlights the common occurrence of hypokalemia in acute ischemic stroke and the association of various factors. A proactive approach to manage hypokalemia is essential for improving patient outcomes. Healthcare providers should monitor potassium levels routinely and assess neurological and swallowing functions. By recognizing individual risk factors, targeted interventions can enhance recovery and quality of life for stroke patients.