In this section
This page contains Clinical Practice Guidelines for the administration of Standard Heparin infusions, systemic lytic therapy and the management of a blocked central venous access device.
In addition, the Clinical Haematology department has developed guidelines to support clinician’s management of warfarin and low molecular weight heparin (Clexane). These can be accessed from the department’s webpage, or via the links below
The following are guidelines for the commencement and maintenance of Unfractionated Heparin (UFH) infusions, also known as Standard Heparin. It may be necessary to modify this protocol according to individual patient requirements. Outside of Rosella and Koala, the Clinical Haematology Department should be consulted before commencing a UFH infusion
At RCH we only administer UFH by intravenous route. This guideline applies to the intravenous route only. UFH is compatible with 5% Dextrose and 0.9% NaCl.
Intravenous orders for UFH must state ALL of the following:
NB Patients that are fluid restricted may require more concentrated UFH solutions than that recommended based on weight. If this is necessary, increased vigilance is required and a Clinical Haematology consult is highly recommended.
b. Draw up required units of heparin and volume of diluent
(maximum starting dose 1000units/hour)
stopped or interrupted for other medication.
programing infusion pumps when commencing UFH infusions, careful checking
procedures are required, including double checking at the patient bedside.
Patient Weight x Dose Required (units/kg/hr) / Heparin concentration (units/mL) = mls/hour to be
9. Flow rate (ml per hour) will vary according to weight.
The table below provides examples of UFH calculations based upon patient weight. All dose calculations are based upon age-appropriate UFH units/kg recommended to achieve therapeutic anticoagulation.
UFH units required/hour
*maximum upper limit of 1000 units per hour starting dose breached by Weight x 18unit/kg/hr calculation.
Monitoring therapeutic UFH infusions
UFH is monitored using the APTT assay. The table below summarises a UFH dosing nomogram based on the APTT result. APTT results across laboratories cannot be reliably compared.
In some clinical scenarios, the APTT may not be accurate, and an anti-Xa assay may be used. Within adult based studies, an anti-Xa assay of 0.35-0.7 units/mL equates to a therapeutic UFH dose. Consultation with the Clinical Haematology unit is recommended in such scenarios.
If two unsuccessful attempts to obtain a venous APTT have occurred, contact the Clinical Haematology department before further attempts are made.
Rate change (units/hr)
*Bolus may be appropriate depending on clinical situation and perceived bleeding risk. Consult the Clinical Haematology department.
3. The rate changes suggested in the table above are to be calculated as a percentage of
the total infusion, that is, in units/kg/hour.
4. Do NOT turn off UFH infusion prior to collecting an APTT or anti-Xa assay.
5. APTT blood samples should NOT be drawn from the same line (or limb) as the UFH
infusion. If this cannot be avoided, a minimum discard volume of 5mL should be collected
prior to collecting the APTT or Anti-Xa sample.
6. Coagulation tubes must be filled exactly to the specified mark to avoid erroneous results.
7. Twice weekly FBEs, (platelet count) and renal function are required. If there is an abrupt decrease in platelet count, (eg 50%) consult the Clinical Haematology department.
8. The duration of UFH therapy is dependant upon the primary problem. Please consult the Clinical Haematology department for guidelines.
The major adverse event potentially related to UFH infusion is bleeding. The reported frequency of UFH-related major bleeding varies significantly, from major bleeding rates ranging from 0% to 24 % of patients exposed to UFH. If a patient on UFH develops bleeding, cease UFH infusion and seek urgent Clinical Haematology consult. Heparin induced thrombocytopaenia (HIT) is a potentially life-threatening UFH-related adverse event. In adults, the reported incidence ranges from 3-5%. In children, the incidence is likely much lower. Thrombocytopaenia occurring in the setting of UFH therapy is likely to be secondary to patient's comorbidity. Screening for the possibility of HIT requires Clinical Haematology consultation.
If anticoagulation with UFH needs to be discontinued for clinical reasons, termination of the UFH infusion will usually suffice. If an immediate effect is required, consider administering protamine sulphate.
Protamine is a medication that requires a high level of caution when being prescribed and administered. Outside of cardiac surgery and ICU, Clinical Haematology approval is required for the use of protamine – do not allow this to lead to delayed administration in the case of bleeding. Contact the appropriate senior person immediately.
Protamine sulphate neutralises UFH by virtue of its positive charge. Following IV administration, neutralisation occurs within 5 minutes. The dose of protamine sulphate is based on the amount of UFH received in the previous 2 hours as follows:
Time since Last UFH Dose
Protamine Dose (mg) per 100units UFH received
< 30 min
> 120 min
The maximum dose of protamine sulphate, regardless of the amount of UFH received is 50mg except for reversal of UFH following cardiopulmonary bypass. Protamine sulphate is usually administered in a concentration of 10mg/mL at a rate not to exceed 5mg/minute. If administered too quickly, protamine sulphate may cause cardiovascular collapse. Patients with known hypersensitivity reactions to fish, and those who have received protamine- containing insulin or previous protamine therapy may be at risk of hypersensitivity reactions to protamine sulphate. Obtain blood for PT and APTT 15 min after the administration of protamine sulphate.
Obtain CXR to confirm line placement and absence of kinking.
Blood Related Blockage
Chemical Related Blockage
Single lumen CVAD
Double lumen CVAD
1.5ml x 2-4 hours*
1.5ml per lumen x 2-4hrs*
1.5ml x 2-4 hrs*
* HCl and tPA are prepared by Pharmacy. If unable to obtain blood return, repeat once in 24 hours.
* After 2-4 hours instillation of each drug, withdraw drug. If possible flush with 0.9% N/saline and attempt to aspirate blood.
Linogram to determine: - Location of CVAD's tip.
If venography is unavailable, perform doppler ultrasound of large vessels near and including CVAD
However, this technique is only accurate in 20% of cases in detecting large vessel thrombus of the upper venous system. Venography is the gold standard investigation for the diagnosis of large upper venous system thrombosis.
Consultation with the Clinical Haematology department is available.
Contact can be made on ext. 52605 during office hours or page the on-call Haematologist through the RCH switchboard after hours.
Urokinase is not available at the Royal Children's Hospital. All line related blockages thought to be thrombus related are treated with Alteplase (tPA). Streptokinase is still available in this state, however there is a substantial risk of anaphylaxis on repeat exposure. This risk is readily avoidable with the use of tPA and therefore the use of streptokinase is not recommended.
This is a guideline for the use of systemic lytic therapy. There is no robust data to support the use of local lytic therapy in infants and childrenexcept for line blockages (see guideline for CVAD malfunction). Administration of systemic lytic therapy within the RCH requires involvement of the Clinical Haematology department.
DO NOT use Streptokinase if the patient has previously been exposed to streptokinase. Premedicate with Paracetamol and/or promethazine due to potential for allergic reactions.
6. Administer Lytic therapy as per following guidelines:
Maximum loading dose
0.5mg/kg/hour over 6 hours.
2000 units/kg over 10 minutes
1000 units/kg/hour over 6 hours
*occasionally "front-loaded" tPA therapy is indicated. The Clinical Haematology department will discuss this option with clinical teams as indicated.
Based upon case series reports and cohort studies, 30-50% of patients receiving systemic lytic therapy will experience a bleeding event, with approximately 11-40% of patients requiring red blood cell transfusion. An increased likelihood of bleeding is associated with a prolonged lytic therapy infusion. Minor bleeding usually presents as oozing from a wound or puncture site. Major bleeding is defined as bleeding into a body cavity (intracranial, retroperitoeal, thoracic) or external bleeding requiring transfusion.
If bleeding occurs, cease tPA and heparin infusions and seek an urgent Clinical Haematology review. Treatment with local pressure is usually sufficient management of bleeding from wound or puncture sites. Cryoprecipitate, antifibrinolytics and blood products may be indicated for the management of major bleeding.
Consultation with the Clinical Haematology Department is required. Contact can be made on ext. 52605 during office hours or page the on-call Haematologist through RCH switchboard after-hours.
Urokinase is not available at the Royal Children's Hospital. All CVAD related blockages thought to be thrombus are treated with Alteplase (tPA). Streptokinase is still available in this state, however there is a substantial risk of anaphylaxis on repeat exposure. This risk is readily avoidable with the use of tPA and therefore the use of streptokinase is not recommended.
Consultation with the Clinical Haematology Department is required for therapeutic infusions outside of the Paediatric Intensive Care Unit and Cardiac Unit. Contact can be made by paging the Inpatient Clinical Haematology Registrar on pager 5030 during office hours or page the on-call Haematologist through RCH switchboard after hours.
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