Umbilical artery catheters in the newborn: effects of catheter design (end vs side hole)

The evaluation and management of postnatal thromboses

In the pediatric population, neonates have the highest risk for thromboembolism (TE), most likely due to the frequent use of intravascular catheters. This increased risk is attributed to multiple risk factors. Randomized clinical trials dealing with management of postnatal thromboses do not exist, thus, opinions differ regarding optimal diagnostic and therapeutic interventions. This review begins with an actual case study illustrating the complexity and severity of these types of cases, and then evaluates the neonatal hemostatic system with discussion of the common sites of postnatal thrombosis, perinatal and prothrombotic risk factors, and potential treatment options. A proposed step-wise evaluation of neonates with symptomatic postnatal thromboses will be suggested, as well as future research and registry directions. Owing to the complexity of ischemic perinatal stroke, this topic will not be reviewed.

Thrombosis in the critically ill neonate: incidence, diagnosis, and management

Among children, newborn infants are most vulnerable to development of thrombosis and serious thromboembolic complications. Amongst newborns, those neonates who are critically ill, both term and preterm, are at greatest risk for developing symptomatic thromboembolic disease. The most important risk factors are inflammation, DIC, impaired liver function, fluctuations in cardiac output, and congenital heart disease, as well as exogenous risk factors such as central venous or arterial catheters. In most clinically symptomatic infants, diagnosis is made by ultrasound, venography, or CT or MRI angiograms. However, clinically asymptomatic vessel thrombosis is sometimes picked up by screening investigations or during routine imaging for other indications. Acute management of thrombosis and thromboembolism comprises a variety of approaches, including simple observation, treatment with unfractionated or low molecular weight heparin, as well as more aggressive interventions such as thrombolytic therapy or catheter-directed revascularization. Long-term follow-up is dependent on the underlying diagnosis. In the majority of infants, stabilization of the patients’ general condition and hemodynamics, which allows removal of indwelling catheters, renders long-term anticoagulation superfluous. Nevertheless, in certain types of congenital heart disease or inherited thrombophilia, long-term prophylaxis may be warranted. This review article focuses on pathophysiology, diagnosis, and acute and long-term management of thrombosis in critically ill term and preterm neonates.

Umbilical artery catheters in the newborn: effects of catheter design (end vs side hole)

BACKGROUND

This section is under preparation and will be included in the next issue.

OBJECTIVES

To determine whether the design of an umbilical arterial catheter influences the frequency of ischemic events, aortic thrombosis, intraventricular hemorrhage, mortality or necrotising enterocolitis in newborn infants.

SEARCH STRATEGY

Randomized and quasi randomized controlled trials of umbilical catheterization use were obtained from the following sources: 1. Effective Care of the Newborn Infant, edited by JC Sinclair and MB Bracken. 2. Medline Search using Melvyl Medline Plus and the keyword headings 'Umbilic#', 'Catheter#' and subject heading 'Infant, Newborn' 3. Search of personal data files

SELECTION CRITERIA

Randomized trials in newborn infants of any birthweight or gestation. Comparison of end hole catheters with side hole catheters. Clinically important end points such as ischemic events or aortic thrombosis.

DATA COLLECTION AND ANALYSIS

There appears to be only a single trial which has addressed this issue (Wesstrom 1979).

MAIN RESULTS

End hole catheters are associated with a much decreased risk of aortic thrombosis compared to side hole catheters. RR = 0.27 (95% CI 0.11, 0.67)

REVIEWER'S CONCLUSIONS

Side hole catheters should be avoided for umbilical arterial catheterisation in the newborn.