Unfractionated heparin dosing requirements in the presence of inflammation during the first six months of life

Heparin Dosing Regimen Optimization in Veno-Arterial Extracorporeal Membrane Oxygenation: A Pharmacokinetic Analysis

BACKGROUND

Unfractionated heparin is administered in patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Anticoagulation monitoring is recommended, with an anti-activated factor X (anti-Xa) targeting 0.3 to 0.7 IU/mL. Owing to heparin's heterogeneous pharmacokinetic properties, anti-Xa is unpredictable, generating a challenge in anticoagulation practices. The aim of this study was to build a pharmacokinetic model of heparin accounting for potential confounders, and derive an optimized dosing regimen for a given anti-Xa target.

METHODS

Adult patients undergoing VA-ECMO were included between January 2020 and June 2021. Anticoagulation was managed with an initial 100 IU/kg heparin loading dose followed by a continuous infusion targeting 0.2 to 0.7 IU/mL anti-Xa. The data were split into model development and model validation cohorts. Statistical analysis was performed using a nonlinear mixed effects modeling population approach. Model-based simulations were performed to develop an optimized dosing regimen targeting the desired anti-Xa.

RESULTS

A total of 74 patients were included, with 1703 anti-Xa observations. A single-compartment model best fitted the data. Interpatient variability for distribution volume was best explained by body weight, C-reactive protein and ECMO indication (post-cardiotomy shock or medical cardiogenic shock), and interpatient variability for elimination clearance was best explained by serum creatinine and C-reactive protein. Simulations using the optimized regimen according to these covariates showed accurate anti-Xa target attainment.

CONCLUSION

In adult patients on VA-ECMO, heparin's effect increased with serum creatinine and medical indication, whereas it decreased with body weight and systemic inflammation. We propose an optimized dosing regimen accounting for key covariates, capable of accurately predicting a given anti-Xa target.

Effect of combining anticoagulant and glucocorticoid therapy on mortality in patients with severe COVID-19

Introduction

Coronavirus disease (COVID-19) has spread rapidly to more than 200 countries and regions worldwide. Although several options have been implemented in attempts to control the rate of COVID-19 infection, the mortality rates remain high. The aim of this study is to evaluate whether patients with severe COVID-19 will benefit from the combination of anticoagulant and glucocorticoid therapy.

Methods

A single-center retrospective cohort study of patients with COVID-19 was performed. Several factors influencing patients with COVID-19 have been analyzed retrospectively, including basic conditions, inflammatory factors, coagulation parameters, medications, and outcomes. Continuous and categorical variables have been evaluated via binary logistic regression analysis to predict mortality. The association between anticoagulant treatment and outcomes has also been evaluated, stratifying patients according to glucocorticoid treatment.

Results

61 patients with severe COVID-19, including 23 critically ill patients have been enrolled in the study. In those with severe and critical illness COVID-19, mortality rate was lower in those who received combined anticoagulant and glucocorticoid with odds ratio of 0.003 ( p = 0.042) and 0.031 ( p = 0.046), respectively. In cases of severe COVID-19, those who were treated with both anticoagulant and glucocorticoid had lower mortality (17.6%) than those treated with glucocorticoid alone (31.8%), although this did not reach statistical significance ( p = 0.321). In the critically ill COVID-19 patients who received both anticoagulant and glucocorticoid, there was significantly lower mortality (30%) than those who received glucocorticoid alone (77.8%) ( p = 0.047). Seventy-five percent of non-survivors of COVID-19 met the International Society on Thrombosis and Haemostasis criteria of disseminated intravascular coagulation (total points ≥5).

Conclusion

Patients with severe COVID-19 or critically ill patients with COVID-19 may benefit from the combination therapy of anticoagulant and glucocorticoid. As the disease getting severe, more benefits may be obtained from the combination therapy.

Retrieval of an Intracardiac Cannula Fragment via Femoral Access in a Premature Infant

A preterm infant with birth weight 1,550 g had an intravenous foreign body between the external iliac vein and the common iliac vein, which accidentally happened during peripheral intravascular central catheter insertion by the Seldinger technique. The infant initially received conservative management and close monitoring. Antibiotics were administered 4 weeks to treat culture positive sepsis and meningitis. The infant was clinically stable till the cannula fragment migrated to the heart 34 days later. At that time, his weight was 2,200 g, and he was full fed. The cannula fragment was retrieved by emergency interventional radiology via the right femoral access, with no complications. The infant was discharged at 45 days of age and closely followed up post-discharge. He is currently 6 months old, with normal development. This is the first case of successful percutaneous retrieval of an intracardiac intravenous cannula fragment via femoral access in a premature infant in China.