**3.4.1 Commonly used anticoagulants**

#### **3.4.1.1 Unfractionated heparin**

The following disadvantages should be considered: the need for venous access for therapy and monitoring, age-dependent unpredictable pharmacokinetics; normal AT levels required; monitoring by a PTT prone to pre-analytic errors; risk for bleeding; risk for HIT. Intravenous UFH should only be given in the initial phase of antithrombotic therapy and then switched to LMWH.

#### **3.4.1.2 Low - molecular - weight heparin**

Advantages are easy subcutaneous administration once daily without need of venous access, predictable pharmacokinetics, minimal monitoring, minimized bleeding complications, reduced risk of HIT. Infants < 5 kg required about 50% higher doses than older children to reach equivalent anti-FXa levels.(Sutor et al, 2004) As a general guideline

Venous Thromboembolism in Neonates, Children and

**3.4.1.5 Infusion of deficient inhibitors of hemostasis** 

hereditary TTP due to PS or ADAMTS13 deficiency,respectively.

months (**Table 6**).

**3.4.2 New anticoagulants** 

**3.4.3 Special conditions** 

3.4.3.1.1 UFH

3.4.3.1.3 LMWH

toxicity.(Balsa, 2005; Kuhle et al, 2006).

**3.4.3.1 Prophylaxis of CVC occlusion** 

3.4.3.1.2 Thrombolytic agents (urokinase, rt - PA)

contradictory results.(Aquino et al, 2002; Solomon et al, 2000)

individual decision. For the recommended dosage see **Table 4**.

3.4.3.1.4 Oral anticoagulation with vitamin K - antagomist

Patients with Chronic Renal Disease – Special Considerations 61

Warfarin and phenprocoumon are usually administered for oral anticoagulation and inhibit g-carboxylation of vitamin K–dependent proteins. Considerable variation due to nutrition, co-medication, intercurrent illness and difficult monitoring requires close supervision and dose adjustment. We administer vitamin K antagonists in cases of prophylaxis exceeding 6

In cases of thrombosis with hereditary or acquired deficiencies of coagulation inhibitors, replacement therapy may be an option. Concentrates of AT and PC are commercially available and are life saving in conditions of purpura fulminans due to inhibitor deficiency. PC concentrate also proved to be effective in heterozygous or acquired PC deficiency. Fresh frozen plasma is the only but effective option of treating patients with purpura fulminans or

The limitations of the traditional anticoagulants are particularly obvious in pediatrics; hence, the promotion of the new drugs already approved in adults urgent. Yet there is but individual experience in children with the following substances: the pentasaccharides fondaparinux and idraparinux, and the direct thrombin inhibitors hirudin, bivalirudin, argatroban; ximelagatran has been withdrawn from the market because of hepatic

Prophylactic UFH seems to significantly decrease CVC-related DVT as well as bacterial colonization of the catheter.(Hentschen & Sutor, 2002) Heparin-bonded catheters do not reduce clot formation and bacterial colonization beyond 24 hours after CVC insertion.

Thrombolytic therapy is widely and safely used for the management of occluded catheters. There are only a few studies using thrombolytic agents prophylactically in order to reduce catheter infections and occlusions. Some studies show a substantial benefit of thrombolytic agents over UFH or no prophylaxis.(Hentschen & Sutor, 2002) whereas others get

Prophylactic use of LMWH has been efficient and safe in the treatment and prevention of DVT in children with cancer.(Elhasid et al, 2001; Massicotte et al, 2003; Tabori et al, 2006) However, LMWH to maintain CVC-patency and prevent CVC-related DVT has to remain an

There are no data for children on using low-dose oral anticoagulation to prevent CVCassociated DVT and to maintain catheter patency. Considering the heterogeneous pediatric

we recommend LMWH with therapeutic anti-Xa levels for 4–6 weeks, followed by prophylactic dosage up to 6 months. For the treatment duration of different sites, types and age groups refer to references (Monagle et al, 2004; Andrew et al, 2000).
