Antithrombotic Therapy in Children: Arterial Thromboembolic Disease

Antithrombotic Therapy in Children: Arterial Thromboembolic DiseaseArterial Thromboembolic Disease
Etiology: The most common cause of arterial thromboembolic disease in children is catheters. These include cardiac catheterization, and central or peripheral arterial lines in the intensive care setting. Noncatheter-related arterial thrombotic complications are rare and occur in Takayasu’s arteritis, in arteries from transplanted organs, in giant coronary aneurysms secondary to Kawasaki’s disease, and as complications of some forms of congenital heart disease and cerebral vessels from local lesions or emboli from cardiac or other locations. flovent inhaler

Cardiac Catheterization: In the absence of prophylactic anticoagulation, the incidence of symptomatic thrombotic complications following cardiac catheterization via the femoral arteiy is approximately 40% (Table 12). Younger children (<10 years of age) have an increased incidence compared to older children. Prophylactic anticoagulation with aspirin does not significantly reduce the incidence of arterial thrombosis (one level II study). However, anticoagulation with 100 to 150 U/kg of heparin reduces the incidence from 40 to 8% (one level II study). One level II study suggests that 50 U/kg bolus of heparin may be as efficacious as 100 U/kg when given immediately after arterial puncture, however this study was underpowered, and one could not recommend 50 U/kg as optimal prophylaxis at this time. Recent advances in interventional catheterization have resulted in the use of larger catheters and sheaths that may increase the risk of thrombotic complications. Further heparin boluses are frequently used in prolonged procedures (^60 min), especially during interventional catheterizations; the benefits of this practice, however, are not known. A short limb and claudication are the long-term consequences of femoral artery thrombosis in children.
Umbilical Artery Catheterization: Umbilical arterial catheterization is necessary for the administration of supportive care critical to the survival of sick newborns (Table 13). Umbilical artery catheter tips are either positioned high (level of T5 to T10) or low (level of L3 to L5). The optimal position to minimize thrombotic complications remains uncertain. The position the umbilical artery catheters may affect both the frequency of thrombosis and ICH. A low-dose, continuous heparin infusion (3 to 5 U/h) is commonly used to maintain catheter patency.

Table 12—Cardiac Catheterization in Children: Arterial

Study Level Intervention PatientNo. Outcome
Bleeding TE
Freed et al, 1974197 II Aspirin (15 mg/kg) 37 0 8
Placebo 58 0 14
Freed et al, 1974196 I Heparin (1 mg/kg) 37 0 2
Placebo 40 0 10f
Saxena et al, 1997198 II Heparin 50 IU/kg 183 0 18
Heparin 100 IU/kg 183 0 17

Table 13—Umbilical Artery Catheterization

Source, yr Level Intervention No. of Patients Bleeding Event (B or TE)
Jackson et al, 1987204 II HB-PU 61 NRf 13 TE
PVC 64 NR 23 TE
Horgan et al, 1987207 II Heparin 59 NR 16 TE
No heparin 52 NR 18 TE
Rajani et al, 1979203 I Heparin 32 NR 4 B§
Placebo 30 NR 19 B
David et al, 1981205 II Heparin 26 o| 3B§
No heparin 26 ot 15 B
Bosque and Weaver, 1986206 II Heparin (C) 18 NR 0B§
Heparin (I) 19 NR 8 B
Horgan et al, 1987207 II Heparin 59 NR 2 B§
No heparin 52 NR 10 B
Ankola and Atakent, 1993208 II Heparin 15 4 ICH 2B§
No heparin 15 5 ICH 11 B
Chang et al, 1997209 II Heparin 55 19 ICH NR
No heparin 58 17 ICH NR/span>