Neonatal Venous Thromboembolism

Abstract

Neonates are the pediatric population at highest risk for development of venous thromboembolism (VTE), and the incidence of VTE in the neonatal population is increasing. This is especially true in the critically ill population. Several large studies indicate that the incidence of neonatal VTE is up almost threefold in the last two decades. Central lines, fluid fluctuations, sepsis, liver dysfunction, and inflammation contribute to the risk profile for VTE development in ill neonates. In addition, the neonatal hemostatic system is different from that of older children and adults. Platelet function, pro- and anticoagulant proteins concentrations, and fibrinolytic pathway protein concentrations are developmentally regulated and generate a hemostatic homeostasis that is unique to the neonatal time period. The clinical picture of a critically ill neonate combined with the physiologically distinct neonatal hemostatic system easily fulfills the criteria for Virchow’s triad with venous stasis, hypercoagulability, and endothelial injury and puts the neonatal patient at risk for VTE development. The presentation of a VTE in a neonate is similar to that of older children or adults and is dependent upon location of the VTE. Ultrasound is the most common diagnostic tool employed in identifying neonatal VTE, but relatively small vessels of the neonate as well as frequent low pulse pressure can make ultrasound less reliable. The diagnosis of a thrombophilic disorder in the neonatal population is unlikely to change management or outcome, and the role of thrombophilia testing in this population requires further study. Treatment of neonatal VTE is aimed at reducing VTE-associated morbidity and mortality. Recommendations for treating, though, cannot be extrapolated from guidelines for older children or adults. Neonates are at risk for bleeding complications, particularly younger neonates with more fragile intracranial vessels. Developmental alterations in the coagulation proteins as well as unique pharmacokinetics must also be taken into consideration when recommending VTE treatment. In this review, epidemiology of neonatal VTE, pathophysiology of neonatal VTE with particular attention to the developmental hemostatic system, diagnostic evaluations of neonatal VTE, and treatment guidelines for neonatal VTE will be reviewed.

Risk Factors Linked to Central Catheter-Associated Thrombosis in Critically Ill Infants in the Neonatal Intensive Care Unit

“…8 In contrast, a prospective study of neonates who underwent central venous catheter placement indicated a 13% incidence of CT, 9 while another evaluating only umbilical catheters revealed a higher incidence of 22%. 10,11 These studies taken together with our study suggest that neonates with catheters are at high risk for CT, but CTs are not always associated with clinically significant symptoms. This suggests that other factors must play an important role in those CT that become symptomatic.…”

“…A recent review identified that the distribution of venous thromboembolism across the pediatric age group is bimodal, with one spike in the neonatal period and a second spike in the adolescent period. 11 Age has been positively associated with thrombosis in critically ill patients in the pediatric intensive care unit, where children older than 13 years were significantly more likely to develop CT compared with infants younger than 1 year. 22 A systematic review of several adult population-based studies found that older age was significantly associated with catheter-related thrombosis.…”

Inferior vena cava syndrome in neonates: An evidence‐based systematic review of the literature

“…Magnetic resonance imaging/angiography, abdominal computerized tomography (CT), and echocardiography were employed to detect IVC thrombi in five cases, and in two cases the diagnosis was established at postmortem . Although gray‐scale/Doppler ultrasonography is recognized as the modality of choice in suspected neonatal IVC thrombosis, CT provides more detailed information about thrombus extension, but at the expense of radiation exposure . In our review, 75% ( n = 46/61) of the cases were diagnosed by ultrasound alone, while 7% ( n = 4/61) were diagnosed by ultrasound with CT confirmation.…”

“…15,22 Although gray-scale/Doppler ultrasonography is recognized as the modality of choice in suspected neonatal IVC thrombosis, CT provides more detailed information about thrombus extension, but at the expense of radiation exposure. 61 In our review, 75%…”

Venous thromboembolism an observational study to assess the risk of venous thromboembolism in surgical patients.

“…The Virchow's Triad proposes that VTE occurs as a result of blood stasis, vascular endothelial injury and inherited or acquired hypercoaguable states. 2 Keeping in view the pathophysiology of VTE, the patients after surgery are at higher risk of VTE because surgery induces inflammatory responses and hypercoagulable state along with endothelial injury. After surgery limited movements result in venous stasis.…”