Determining the Risk of Elevated Digoxin Concentrations Following Loading Dose in Patients With Acute and Chronic Kidney Disease.

BACKGROUND: The optimal loading dose of digoxin in patients with reduced kidney function is unknown. Tertiary references recommend reduced loading doses; however, these recommendations are based on immunoassays that are falsely elevated by the presence of digoxin-like immunoreactive substances, a problem that is minimized in modern assays. OBJECTIVE: To determine whether chronic kidney disease (CKD) or acute kidney injury (AKI) is associated with supratherapeutic digoxin concentrations after a digoxin loading dose. METHODS: A retrospective analysis on patients who received an intravenous loading dose of digoxin with a digoxin concentration collected 6 to 24 hours after the end of the dose. Patients were stratified into 3 groups: AKI, CKD, and non-AKI/CKD (NKI) based on glomerular filtration rate and serum creatinine. The primary outcome was frequency of supratherapeutic digoxin concentrations (>2 ng/mL) and secondary outcomes included frequency of adverse events. RESULTS: A total of 146 digoxin concentrations were included (AKI = 59, CKD = 16, NKI = 71). Frequencies of supratherapeutic concentrations were similar between groups (AKI: 10.2%, CKD: 18.8%, NKI: 11.3%; P = 0.61). Pre-planned logistic regression demonstrated no significant relationship between kidney function group and the development of a supratherapeutic concentration (AKI: odds ratio [OR]: 1.3, 95% confidence interval [CI]: 0.4-4.5; CKD: OR 4.3, 95% CI: 0.7-23). CONCLUSION AND RELEVANCE: This is the first study in routine clinical practice evaluating the relationship between kidney function and digoxin peak concentrations that differentiates AKI from CKD. We did not find a relationship between kidney function and peak concentrations; however, the group with CKD was underpowered.

Use of four-factor prothrombin complex concentrate (4F-PCC) for management of bleeding not associated with therapeutic anticoagulant use.

INTRODUCTION: Four-factor prothrombin complex concentrate (4F-PCC) may be an option for patients with bleeding unrelated to therapeutic anticoagulation to help with bleeding cessation and reduce blood component requirements. MATERIALS AND METHODS: Retrospective, observational study of adult patients who received 4F-PCC for bleeding not associated with therapeutic anticoagulation between June 2019 and July 2021. Primary outcome was to describe off-label 4F-PCC use in patients not on therapeutic anticoagulation for bleeding management in surgical and non-surgical patients. Additional outcomes evaluated were blood product use, chest tube and drainage output, and coagulation studies before and after 4F-PCC administration as well as other hemostatic agent use and thromboembolic events. RESULTS: Seventy-six patients were included; median age 64 years (IQR 50-69), 66% of bleeding events were associated with surgery, and the majority of 4F-PCC doses ordered by cardiac surgery (68.4%). A total of 110 4F-PCC doses were administered; median 1 dose/patient (IQR 1-2), median total dose 1000 units (IQR 500-1484). Other hemostatic agents commonly administered were protamine (59%), desmopressin (43%), and tranexamic acid (42%). Packed red blood cells, fresh frozen plasma, platelet, and cell saver blood administration and prothrombin time (PT), international normalized ratio (INR), and partial thromboplastin time (aPTT) were significantly reduced following 4F-PCC administration. Eight patients (11%) experienced thromboembolic complications. CONCLUSION: Relatively low doses of 4F-PCC (median total dose 1000 units) were associated with decreased blood component requirements and improved PT, INR, and aPTT values in patients with bleeding unrelated to therapeutic anticoagulation. Other hemostatic agent use was common and thromboembolic complications occurred.