Retrospective long-term evaluation of digoxin poisoning in the emergency department

ABSTRACT Retrospective Long-Term Evaluation of Digoxin Poisoning in the Emergency Department Introduction and Objective: Digoxin toxicity can present to the emergency department with subtle signs and symptoms, particularly in elderly patients, due to the drug's narrow therapeutic window. The aim of our study is to identify the priorities in emergency diagnosis and treatment, as well as the risk factors, in patients aged 18 and over who presented to the Emergency Medicine Department of Çukurova University Faculty of Medicine with serum digoxin levels of 2.0 ng/mL or higher. Materials and Methods: In our study, we aimed to evaluate the demographic characteristics (age, sex), comorbidities, clinical signs and symptoms, diagnostic tests and their results (ECG, laboratory findings including glucose, blood urea nitrogen, creatinine, sodium, potassium, complete blood count, CK-MB, troponin), treatment details, echocardiographic findings, serum digoxin levels, treatment methods applied, and clinical outcomes of patients aged 18 years and older who presented to the emergency department between May 1, 2013, and July 31, 2024, with serum digoxin levels of 2.0 ng/mL or higher, using the mREMS score. Findings: Out of the patients, 104 were female (74.3%) and 36 were male (25.7%), with a mean age of 73.6±11.2 years. The most common comorbidities were coronary artery disease (CAD) in 96.4%, heart failure (HF) in 94.3%, hypertension (HT) in 78.6%, diabetes mellitus (DM) in 41.4%, and chronic kidney disease (CKD) in 9.3%. The most frequent presenting complaints were dyspnea (52.9%), gastrointestinal symptoms (33.6%), chest pain (31.4%), syncope (7.1%), and neurological findings (5%). On electrocardiography (ECG), the most common finding was atrial fibrillation with normal ventricular response (47.1%), followed by atrial fibrillation with slow ventricular response (32.1%). When evaluating digoxin levels, a positive correlation was observed with potassium, urea, creatinine, and hemoglobin, whereas a negative correlation was found with leukocyte count. At presentation, 97.9% of the patients (n=137) had a modified Rapid Emergency Medicine Score (mREMS) of <13, and 2.1% (n=3) had a score >13. Among those who died in the emergency department, the mREMS score was found to be >13. Regarding treatments administered, 92.1% of the patients (n=129) received medical treatment targeting comorbidities and metabolic conditions, while in 5% (n=7), only drug discontinuation and observation were performed. No treatment was administered in 2.9% (n=4) of the patients. When evaluating the clinical course in the emergency department (ED), 25.7% (n=36) of the patients were discharged, 18.6% (n=26) were admitted to the cardiology service, 50% (n=70) were admitted to the coronary intensive care unit, and 2.1% (n=3) died in the ED. Results: Digoxin toxicity is more frequently observed in elderly patients, women, and individuals with coronary artery disease (CAD) or congestive heart failure (CHF). In our study, we emphasize the importance of evaluating such patients-especially those presenting to the emergency department with symptoms like dyspnea, nausea, or vomiting—using the Modified Rapid Emergency Medicine Score (mREMS) during triage. If laboratory findings reveal elevated potassium, urea, creatinine, and hemoglobin levels, and the serum digoxin concentration exceeds 2 ng/mL, digoxin toxicity should be strongly suspected. These patients should be promptly assessed and treated in the red zone of the emergency department. Keywords: Emergency, digoxin toxicity, clinical, laboratory, diagnosis