Outcomes of Catheter-Related Arterial and Venous Thrombosis After Enoxaparin Therapy in Neonates and Infants With Congenital Heart Disease

Management strategies for the treatment of iatrogenic vascular injuries in infants and children

BACKGROUND

The care of ill children, from extremely premature infants to late adolescents, increasingly involves the use of invasive monitoring and percutaneous diagnostic and therapeutic interventions. Premature infants, neonates, and small children are at greatest risk for iatrogenic vascular injury. Given the often small diameter of the blood vessels and the ability to develop severe spasm, iatrogenic vascular injury is increasing. The very nature of their hemostatic mechanisms, small vascular diameters, tolerance of severe ischemia, and the potential for rapid growth and remodeling of collateral beds alters decision-making significantly from adults. Surgery, when required, may involve microsurgery and subtle changes in the methods of vascular dissection and arterial repair. There is little information available for the vascular surgeon to understand the risks and nature of these injuries and the options for treatment. This review addresses the mechanisms of and management strategies for the most common iatrogenic injuries.

METHODS

The National Task Force on Pediatric Vascular Care established jointly by the Society for Vascular Surgery and the American Pediatric Surgery Association appointed a working group with expertise in managing pediatric iatrogenic vascular injuries to develop a support document for vascular surgeons. To do this, the published literature was reviewed on pediatric iatrogenic injuries that vascular surgeons might be called to manage. Intracranial injuries and those associated with extracorporeal membrane oxygenation were excluded. The majority of injuries reported in the literature involved femoral and brachial artery cannulation sites. The literature was reviewed by the writing group and the most important of these selected. In addition, consensus expert opinion from the writing group was used when support from the literature was scant.

RESULTS

There were six major types of pediatric iatrogenic vascular injury identified: arteriovenous fistula, pseudoaneurysm, hemorrhage, arterial and venous thrombosis, and pharmacological ischemia. There is little uniform documentation on the diagnosis and treatment of these. Using the available literature and consensus expert opinion of the working group, each of the major categories of iatrogenic injury was defined and management strategies devised.

CONCLUSIONS

There is often a nonsurgical approach to the management of the six major types of iatrogenic injury. It is important for the vascular consultant to understand and incorporate these approaches to develop comprehensive management strategies for children with iatrogenic vascular injuries. When treatment of even the smallest of pediatric patients is undertaken with a clear understanding of the etiology and treatment options, a very high rate of success can be expected.

Pharmacokinetic model-guided enoxaparin dosing in the Neonatal ICU: Retrospective cohort study to plan for prospective feasibility trial

Traditional milligram per kilogram (mg/kg) dosing of enoxaparin in neonates frequently fails to achieve target anti-Xa levels promptly, necessitating repeated laboratory monitoring and dose adjustments. This study investigated whether a personalized dosing strategy based on predicted individual clearance and volume of distribution could improve outcomes, comparing standard-of-care (SOC) mg/kg dosing to pharmacokinetic (PK) model-informed precision dosing (MIPD). A retrospective analysis was conducted on hospitalized neonates treated with enoxaparin at less than 44 weeks postmenstrual age from 2019 to 2022. Data on demographics, drug dosing, PK model covariates, and clinical outcomes were extracted from electronic health records and analyzed using the Pumas-AI Lyv dosing tool. The primary focus was on comparing the initial SOC dose to the MIPD-recommended dose. The secondary outcome measured was the time required to achieve therapeutic anti-Xa levels. The study included 168 neonates with a median postnatal age of 15 days (range 1-149) and a median dosing weight of 3.1 kg (range: 0.82-5.2). MIPD-recommended initial doses were 20%-60% higher than SOC doses in 32% of the cases and over 60% higher in 11% of cases. Neonates who received SOC doses that were much lower than the MIPD recommendation showed the longest delays in reaching therapeutic anti-Xa levels. The results indicate that PK model-informed of enoxaparin dosing leads to higher initial dosages than SOC in neonates, potentially reducing the time to therapeutic anti-Xa levels. These findings are being utilized to define dosing limits for a prospective trial of MIPD in neonatal intensive care settings.

Central venous catheter-associated deep vein thrombosis in critically ill pediatric patients: risk factors, prevention, and treatment

PURPOSE OF REVIEW

Central venous catheter (CVC) placement and ICU admission are the two most important risk factors for pediatric deep vein thrombosis. The optimal prevention and treatment strategies for CVC-associated deep vein thrombosis (CADVT) are unclear, but recently, seminal studies have been published. This review aims to summarize the recent literature on CADVT in critically ill children.

RECENT FINDINGS

Recent publications focused on three themes: risk factors, prevention, and treatment of CADVT. Newly identified risk factors for CADVT relate to Virchow's triad of hemostasis, blood vessel injury, and hypercoagulability. New risk prediction models have moderately good accuracy in predicting CADVT. Though previous data on pharmacologic CADVT prophylaxis was equivocal, recent studies indicate that low-molecular-weight heparin may be effective in preventing CADVT, particularly in critically ill children. Finally, new studies suggest that direct oral anticoagulants and shorter treatment times are noninferior to traditional agents and treatment durations in the treatment of CADVT.

SUMMARY

Recent research suggests new ways to accurately identify children at high risk of CADVT, effectively prevent CADVT, and optimize CADVT treatment. Future research should focus on understanding the pathobiology of CADVT formation, prevention, and treatment in critically ill children.