Nottingham Renal and Transplant Unit GUIDELINES FOR ANTICOAGULATION of EXTRACORPOREAL CIRCUITS Author: Contact Name and Job Title

Initial Version by Sister Ann McGoran, Practice Development Nurse and Dr Simon Roe Consultant Nephrologist. Current version revised by Tina Bennison Haemodialysis Nurse Specialist and Dr Charlotte Bebb, Consultant Nephrologist

Directorate & Speciality

Cancer and Associated Specialities (Renal/Transplant)

Date of submission

April 2014

Explicit definition of patient group to which it applies (e.g. inclusion and exclusion criteria, diagnosis)

Applies to: All patients under the care of the Nottingham Renal and Transplant Unit (including patients dialysing at Kings Mill Hospital and Ilkeston Community Hospital and South Nottingham Dialysis Unit) Excludes: None

Version If this version supersedes another clinical guideline please be explicit about which guideline it replaces including version number.

Replaces February 2012 version. Previous guideline amended low molecular weight heparin from tinzaparin to enoxaparin.

Statement of the evidence base of the guideline – has the guideline been peer reviewed by colleagues?

Evidence level 4 and 5

Evidence base: (1-6) 1

NICE Guidance, Royal College Guideline, SIGN (please state which source).

2a

meta analysis of randomised controlled trials

2b

at least one randomised controlled trial

3a

at least one well-designed controlled study without randomisation

3b

at least one other type of well-designed quasiexperimental study

4

well –designed non-experimental descriptive studies (ie comparative / correlation and case studies)

5

expert committee reports or opinions and / or clinical experiences of respected authorities

6

recommended best practise based on the clinical experience of the guideline developer

Guidelines for Anticoagulation of Extracorporeal Circuits. Revised April 2014. Next revision April 2019.

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Consultation Process

These guidelines were developed in conjunction with medical and nursing staff within the renal unit.

Ratified by:

Renal Unit Senior Staff Meeting

Date:

April 2014

Target audience

Renal unit nursing and medical staff

Review Date: (to be applied by the Integrated Governance Team)

April 2019

A review date of 5 years will be applied by the Trust. Directorates can choose to apply a shorter review date; however this must be managed through Directorate Governance processes. This guideline has been registered with the trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt contact a senior colleague or expert. Caution is advised when using guidelines after the review date.

Evidence base of policy These guidelines have been derived using the following evidence base • Challinor, P and Sedgewick, J (2001) Principles and Practice of Renal Nursing. Nelson Thornes Ltd, UK. • Daugirdas, J.T, Blake, P.G, Todd, S.I (2001).Handbook of Dialysis. 3rd Edition. Lippincott Williams and Wilkins, Philadelphia, USA. • Glynne, P, Allen, A, Pusey, C (2002) Acute Renal Failure in Practice. Imperial College Press, London. • Grant ME, Lovell HB, Weigmann TB (1991) Current use of Anticoagulation in Haemodialysis. Seminars in Dialysis 4; 168-173. • International Technidyne Corporation. Heparinisation in Dialysis and Clinical perspectives. • Norton J et al (1991) Varying Heparin requirements in Haemodialysis patients receiving Erythropoietin. ANNA 19 (4); 367-373. • Polkinghorne, K.R, McMahon, L.P, Becker, G.J. (2002),Pharmachinetic studies of dalteparin, enoxaparin and danaparoid sodium in stable chronic haemodialysis patients. AM J Kidney Disease, Nov; 2002; 40 (5) pages 990 – 995. • Thomas, N, (2003) Renal Nursing. 2nd Edition. Bailliere Tindall. • Vienken J, Bowrys H (1993) Optimisation in Anticoagulation. EDTNA/ERCA Journal XIX (2) • Webb AR, Mythen MG, Jacobson D, Mackie IJ (1995) Maintaining blood flow in the extracorporeal circuit: haemostasis and anticoagulation. Intensive Care Medicine 21; 84-93. • Hetzel G and Sucker C (2005) The Heparins: All a Nephrologist should know. Nephrology, Dialysis and Transplantation, 2005; 20 (10) pages 2036 – 2042. • Lord H, Jean N, Dumont M et al (2002) Comparison between Tinziparin and Standard Heparin for Chronic Haemodialysis in a Canadian Centre. AMJ of Nephrology, 2002; 22 pages 58 – 66.

Guidelines for Anticoagulation of Extracorporeal Circuits. Revised April 2014. Next revision April 2019.

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INTRODUCTION When blood comes into contact with the extra corporeal circuit platelet adherence and activation of the intrinsic clotting cascade occurs, leading to thrombosis. Clots in the dialyser reduce the effective surface area; in extreme situations clots in the circuit may prevent treatment from continuing and result in loss of the blood in the circuit. As with all aspects of extra corporeal therapy the anticoagulant regime should be tailored to the needs of the individual patient, this includes the appropriate anticoagulant drug for the patient’s clinical condition. The aim is to anticoagulate the circuit without putting the patient at risk of bleeding. Unfractionated heparin is widely used for anticoagulation of extra-corporeal circuits. Low molecular weight (LMW) heparins offer advantages compared to unfractionated heparin for chronic anticoagulation of patients receiving haemodialysis. These include an improved lipid profile, less hyperkalaemia and less blood loss. Throughout the treatment the circuit must be observed for signs of clotting, such as: darkening of the blood; clots in the arterial or venous chambers; persistent arterial, venous or TMP alarms when the access patency has been established and streaks in the dialyser after rinsing the dialyser. Best Practice     

These guidelines should be used in conjunction with Extracorporeal protocols and Patient Group Directives (PGD). For Chronic outpatient haemodialysis, the Low Molecular Weight (LMW) heparin Enoxaparin will be used for routine anticoagulation. For acute haemodialysis, the Registered Nurse should liaise with the medical staff to determine the type of anticoagulant to be used. Options include heparin free dialysis, minimal or standard heparinisation with unfractioned heparin. Only Registered Nurses who have been assessed as competent are able to alter anticoagulant regimes as identified within the Patient Specific Directive (PSD). Support Nurses and Health Care Assistants who have had the appropriate training can undertake the blood sampling under the direction of the registered nurse.

Please refer to the algorithms on following pages to establish the method of anticoagulation required.

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Enoxaparin Algorithm 1

Patient Requires Haemodialysis (HD) Therapy? Yes Yes Is Enoxaparin contra-indicated? No

Consider if Heparin PSD applicable. If not, contact Renal SpR or consultant to agree treatment plan.

Is one of the following conditions applicable?  In the immediate Post Operative period (24-48hrs)  Following Severe Trauma  Signs of active bleeding  History of severe bleeding from graft or fistula post dialysis  New HD patient who is undergoing first, second or third HD session No

For Routine Haemodialysis

Yes

For Emergency (Acute) Haemodialysis

Anticoagulant-free HD. No Enoxaparin or Heparin is given during HD Go to Algorithm 2

Flush extracorporeal circuit with 100ml sodium chloride 0.9% hourly to prevent clotting

Note: Post Haemodialysis, central venous catheters are “locked” with Trisodium Citrate (TSC) 46.7% solution as per PSD

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Enoxaparin Algorithm 2

Is this the first time the patient is to be given Enoxaparin at a Haemodialysis (HD) session? Yes

Yes

No

Go to Algorithm 3

Yes

Haemodialysis session planned to last < 3hrs

Haemodialysis session planned to last between 3-4 hrs

Haemodialysis session planned to last >4hrs

Haemodialysis without Enoxaparin. Document No dose used on enoxaparin admin record and update HD prescription.

Give Enoxaparin 20mg (weight 4hrs

Previous HD given enoxaparin: 20mg (weight < 60kg) or 40mg (weight ≥ 60kg)

Previous HD given Enoxaparin starting dose 40mg

Circuit clotted on previous session? No

Haemodialysis without Enoxaparin. Document No dose used on enoxaparin admin record and update HD prescription. If no clots observed then continue without Enoxaparin on next HD session.

Yes

Give Enoxaparin 20mg (weight < 60kg) or 40mg (weight ≥ 60kg) into the arterial limb of the HD circuit. Document dose used on Enoxaparin admin record and update HD prescription. If no clots observed then continue with this dose on next HD session. *

No

Yes

Yes

If clots form increase Enoxaparin dose by 20mg increment on next dialysis (maximum dose 80mg) into the arterial limb of the HD circuit. Document dose used on enoxaparin admin record and update HD prescription. If no clots observed then continue with this dose on next HD session. * If maximum dose given and extracorporeal circuit still clotted, refer patient to Renal SpR or Consultant.

No

Give Enoxaparin 40mg into the arterial limb of the HD circuit. Document dose used on enoxaparin admin record and update HD prescription. If no clots observed then continue with this dose on next HD session. *

* If extracorporeal circuit clotted on greater than one isolated occasion despite using higher Enoxaparin dose refer patient to Renal SpR or Consultant. Note: Post Haemodialysis, central venous catheters are “locked” with Trisodium Citrate (TSC) 46.7% solution as per PSD.

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USE OF ENOXAPARIN FOR ANTICOAGULATION DURING CHRONIC HAEMODIALYSIS Enoxaparin is a low molecular weight heparin. It is given as a single bolus dose into the arterial port of the haemodialysis circuit at the start of dialysis. Low molecular heparins have proven safety, equal efficacy and easier handling than unfractioned heparin. Enoxaparin sodium. Clexane® 20mg, 40mg, 60mg and 80mg Prefilled syringes. Monitoring is generally unnecessary, but if required should be carried out by measuring factor Xa levels (aiming for Anti Xa levels at 1 hour post dialysis of 0.4-0.5 u/ml). Increases in APTT or activated clotting time may occur but are not linearly related to antithrombotic activity and are therefore unsuitable methods of monitoring therapy.

Contra-indications Refer to SPC for Enoxaparin Sodium / BNF / Renal pharmacist. 1. Acute renal failure 2. Pericarditis 3. Disseminated intravascular coagulation(DIC) 4. Active bleeding conditions, including recent stroke 5. Hypersensitivity to enoxaparin or any of the ingredients 6. Heparin induced thrombocytopenia (due to potential cross-reactivity with LMW heparins) 7. Dialysis sessions < 3 hours duration and have had a dialysis session without enoxaparin and without clotting the circuit on a previous session. 8. Patients requiring invasive procedures within 12 hours of the end of extracorporeal therapies. 9. A current prescription for unfractioned heparin or treatment dose low molecular weight heparin for another indication 10. Patients requiring anticoagulant free therapy NB. Prophylactic enoxaparin used for VTE prevention at dose of 20mg daily is not a contraindication for use on dialysis. In this case both the prophylactic enoxaparin and the IV dose on dialysis should be given.

Monitoring Instructions on identifying, managing and reporting possible adverse outcomes      

New starters should have their platelet count checked within 5 – 21 days of starting low molecular weight heparin or heparin as there is a risk of Heparin Induced Thrombocytopenia (HIT). Patients receiving chronic haemodialysis treatment require a full blood count (FBC) monthly to monitor platelet function. Patients who have had surgery must have all wounds and drains monitored regularly for signs of bleeding. Observe the extracorporeal circuit during each treatment for any signs of clotting. Monitor needle sites following removal for prolonged bleeding. Nursing staff with concerns about anticoagulation prescriptions should discuss these

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with renal medical staff (SpR or Consultant).

Description of circumstances in which further advice should be sought from a doctor      

Patients with severe liver insufficiency demonstrated by a prolonged INR (>1.5) and not on any oral anticoagulants Patients who are significantly thrombocytopenic (Platelets < 100 x109/L) Patients who are currently breast-feeding Patients with hypersensitivity to heparin or to any other Low Molecular Weight Heparin (eg Tinzaparin or Dalteparin) If extracorporeal circuit clotted on greater than one isolated occasion despite using higher Enoxaparin dose, refer patient to renal SpR or consultant. Patients with any signs of haemorrhage.

Dose Enoxaparin is administered into the injection port on the arterial line as an intravenous bolus at the beginning of each dialysis session. The drug is dosed according to the length of dialysis and the weight of the patient. Indication Dialysis < 3 hours Dialysis 3 - 4 hours

Dose No Enoxaparin Give Enoxaparin Patient weight < 60kgs give 20mg enoxaparin Patient weight ≥ 60kgs give 40mg enoxaparin into the arterial line injection port on the haemodialysis blood circuit prior to the dialyser. (Maximum dose 80mgs per dialysis session)

Dialysis time > 4 hours or patients dialysing ≤ 4 hours who have had previous episodes of clotting

Give 40mgs enoxaparin into the arterial line port on the haemodialysis blood circuit prior to the dialyser. (Maximum dose 80mgs per dialysis session)

The prefilled syringes will be available on the dialysis units in two different strengths Strengths 20mg

Colour GOLD

40mg

MAUVE

If a dose increase is required then a combination of the two strengths are to be used for example: Enoxaparin 20mg +enoxaparin 40mg = enoxaparin 60mg Enoxaparin 40mg +enoxaparin 40mg = enoxaparin 80mg Enoxaparin 80mg is the MAXIMUM DOSE per dialysis session

Reversal of enoxaparin using protamine Before administering protamine to any patient, advice must be sought from a senior member of the nephrology team. The anticoagulant effects of enoxaparin can only be partially reversed

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using protamine; the manufacturers of enoxaparin estimate that following administration of protamine, a maximum of 60% of the anticoagulant effects of enoxaparin can be neutralised. The initial dose of protamine used should be 1mg/kg, up to a maximum dose of 50mg. The following table summarises the dose of protamine that should be used for each of the doses of enoxaparin used during haemodialysis. Enoxaparin Dose 20 mg 40 mg 60 mg 80 mg

Protamine Dose 20 mg 40 mg 50 mg 50 mg

Further use of protamine, following the initial dose recommended above, should be discussed with a haematologist. Protamine should be administered undiluted by slow intravenous injection, at a maximum rate of 5mg/minute. The dose can be diluted with 5% Glucose or 0.9% Sodium Chloride to aid slow administration. Protamine 50mg/5ml vials are kept as a stock item on Bramley Ward, Carrel Ward, Centenary, Dialysis Unit & Main Dialysis Unit.

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USE OF HEPARIN SODIUM 1000 units/ml FOR ANTICOAGULATION DURING ACUTE EXTRA-CORPOREAL THERAPIES Indications for use Unfractionated heparin is used as the anticoagulant of choice in the extra corporeal circuit for acute therapies. The effect of heparin is immediate and has a short half-life (30 minutes to 2 hours after discontinuation). However in patients with renal failure the effect can last 24 hours. A bolus dose may be given during the “bleed out” procedure, by a registered nurse, into the arterial side of the circuit just as the blood reaches the blood pump insert. This raises the blood clotting time sufficiently to prevent the blood from clotting without increasing the patient’s risk of bleeding. Best Practice Bolus doses of heparin should only be programmed and given by Registered Nurses or medical staff. Intravenous drugs can not be administered by a non registered nurse The clotting time is controlled by a maintenance infusion for the duration of the treatment depending on the patient’s access type and the clotting times. Best Practice when bolus doses are used The bolus is administered into the arterial side of the circuit when blood reaches the blood pump. NOTE THAT THE HOURLY MAINTAINANCE RATE SHOULD NOT EXCEED THE BOLUS DOSE.

Cautions Heparin should be used with caution in the following circumstances: PROBLEM Uraemia Peptic ulceration, active bleeding, pre/post operatively Coagulopathies

Pericarditis Oral anticoagulant medications, e.g. warfarin or any other drug which effects platelet function e.g. aspirin/ clopidogrel Thrombocytopenia

RISK Increased risk of bleeding due to platelet dysfunction Increased risk of bleeding Thrombocytopenia, Disseminated Intravascular Coagulation (DIC), Liver disorders, and Haemophilia Heparin use is contra-indicated in patients with Heparin Induced Thrombocytopenia (HIT) Increased risk of cardiac tamponade that would require medical intervention. Increased risk of bleeding due to the effect on platelet function

Increased bleeding risk. If HIT is suspected advice should be sought from medical staff / haematology.

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Long term effects The long-term use of heparin has been associated with serious side effects such as: hair loss, thrombocytopenia, osteoporosis, hyperlipidaemia, pruritis and rashes.

Heparin Induced Thrombocytopenia (HIT) This is a potentially serious although rare problem. Type 1 HIT is characterised by mild thrombocytopenia (platelet count >100). It is non-immune mediated and typically recovers without discontinuation of heparin. Type 2 HIT is antibody mediated, occurs 5-10 days after the initiation of heparin and is associated with thromboembolism. It does not resolve spontaneously and recurs if the patient is re-challenged with heparin.

Procedures for heparinisation There are two procedures for heparinisation using Unfractionated heparin 1. Standard Heparinisation for patients requiring extra corporeal therapy who do not have any clotting problems or bleeding disorders and are not currently taking oral anticoagulants. 2. Reduced Heparinisation for patients requiring extra corporeal therapy who are at an increased risk of bleeding or are currently taking oral anticoagulants. Best Practice If you are unsure which heparin regime is suitable for a particular patient you must consult a senior member of staff It is possible to use less heparin if: •

A fast blood flow is achieved

•

Two needles/ dual lumen access is used

EQUIPMENT LIST Actalyke or haemochron clotting blocks. Actalyke test probe if using the actalyke clotting block for the first sample of the day. ACT sample tubes. 1 ml syringe. 21G needle. The Actalyke clotting block manufacturer recommends daily testing of their clotting blocks to ensure accuracy of the equipment. Please refer to the equipment guidelines for this.

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STANDARD HEPARINISATION IN PATIENTS REQUIRING EXTRACORPOREAL THERAPIES This procedure is used for patients who are stable but require extra corporeal therapy who do not have any clotting problems or bleeding disorders and are not currently taking oral anticoagulants. For patients who are unstable, have a tendency to bleeding or are prescribed oral anticoagulants the procedure for reduced heparinisation should be followed or an alternative anticoagulant / heparin free dialysis utilised. The regime for patients requiring standard heparinisation during extra corporeal therapy is to maintain the clotting time at 1½ times the baseline clotting time. Using the haemochron or actalyke clotting blocks the baseline should be approximately 110 – 180 seconds. Example: If the baseline is 120 seconds then aim for a clotting time of 180 seconds following heparinisation. See appendix 1 for guidance. SAFE PRACTICE. For safety reasons the unit policy is that the CLOTTING TIME SHOULD NEVER EXCEED 220 SECONDS. If the ACT’s are significantly elevated a full clotting screen (PT, APTT) should be assessed.

Principle

Rationale

1. Heparin should be checked by 2 Registered Nurses. Both Nurses sign the additive label.

Drug code of practice

2. Draw up the heparin into the syringe and apply additive label above the level of the plunger. Connect the syringe to the heparin infusion line situated after the arterial pump. Insert with the additive label clearly visible.

Full amount of heparin should be visible to allow for monitoring of the syringe driver.

3. When access has been established flush the lumen at least five times prior to taking the sample (refer to the guidelines on establishing vascular access).

To prevent contamination of the sample with saline, or heparin if the access is a central line.

4. Obtain the baseline blood sample according to the instructions for the actalyke or haemochron equipment.

This enables the nurse to accurately gauge the patient’s response prior to administering any heparin; it also indicates the patient’s clotting status.

Heparin is infused before the dialyser

Best Practice The baseline clotting time is the time it takes for non-heparinised blood to clot. This baseline is essential as individuals respond differently to the same dose of heparin. Principle 5. If the baseline clotting is within normal limits (110 – 180 seconds) give a heparin bolus of 1000 units into the extra corporeal circuit. Set the maintenance heparin dose to 1.0 ml/hr and commence treatment.

Rationale To prevent clotting within the extra corporeal circuit. This allows the effect of the initial bolus to be assessed and to maintain anticoagulation.

Best Practice The baseline clotting time is the time it takes for non-heparinised blood to clot. This baseline is essential as individuals respond differently to the same dose of heparin.

Principle

Rationale

6. Within 3 -5 minutes of commencing treatment take a blood sample from the arterial port of the circuit and recheck the clotting time. 7. Clotting times should be rechecked at least

It takes 3 – 5 minutes for systemic heparinisation to be achieved and the patient’s full response to heparin can then be assessed. To check the adequacy of the maintenance dose of

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hourly depending on the patient’s condition. 8. Maintain the clotting time within the range by adjusting the heparin infusion rate

heparin. The rate of infusion will be tailored according to the patient’s individual response. See appendix 1 for range and response. 9. Discontinue Heparin at the appropriate time To prevent excessive bleeding from the needle sites depending on the type of access. following their removal. It is important that the patient’s clotting times and dose of heparin are recorded so that adjustments can be made for future treatments. BEST LOCAL PRACTICE FOR DISCONTINUATION OF HEPARIN For a fistula: Termination time should be between 30-60 minutes before the end of therapy. This may depend on the maturity and strength of the fistula. For a graft: Termination time should be approximately one hour before the end of therapy. For a central venous catheter: Generally there is no need to stop the heparin before the end of therapy as this could risk the catheter clotting off. If there is clotting in the extra corporeal circuit or excessive bleeding following removal of the needles it may be necessary to check the clotting time prior to the end of subsequent therapies. Best Practice It is important that the patient’s clotting times and dose of heparin are recorded so that adjustments can be made for future treatments.

Principle

Rationale

10a. Observe the bloodlines and filter for signs of clotting i.e. fibrin formation and clots in the venous bubble trap, increased venous pressure and Transmembrane pressure (TMP), darker blood or poor blood clearance on washback. 10b. Observe the temperature of the venous line and the heparin stop time if additional time is required, at the end of the original prescribed treatment time, for isolated ultrafiltration. 11. Document the total amount of heparin given throughout therapy.

Detection of early signs of clotting prevents loss of blood in the filter and circuit. This determines the need to check clotting times during subsequent treatments. As the blood cools the risk of clot formation increases and in isolated ultrafiltration the haematocrit inside the filters is greatly increased. Provides information for future treatments but also informs medical staff of the total amount given should the patient develop a bleed after therapy has been discontinued.

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REDUCED HEPARINISATION IN PATIENTS REQUIRING EXTRACORPOREAL THERAPIES Reduced heparinisation is recommended for patients requiring extra corporeal therapy whom are at an increased risk of bleeding or are currently taking oral anticoagulants. Patients who are at risk of bleeding require a full clotting screen prior to administering any heparin. For patients at an excessive risk of bleeding use the heparin free guideline. This procedure should also be used for patients receiving warfarin therapy. INRs should be checked regularly as directed by the anticoagulant clinic BEST PRACTICE The regime for patients requiring reduced Heparinisation during extracorporeal therapy is to maintain the clotting time at 1 ¼ times the base line clotting time. Using the Haemochron or Actalyke clotting blocks the base line should be approximately 110140seconds. Example: If the base line is 110 seconds aim for a clotting time of 137 seconds during therapy. THE MAXIMUM CLOTTING TIME SHOULD NOT EXCEED 175 SECONDS For patients whose baseline exceeds 175 seconds withhold all heparin and recheck the clotting time within three minutes of commencing extracorporeal treatment. If the clotting time remains above 175 seconds withhold heparin until the clotting time is within the normal baseline range and monitor the patients clotting time every 15 minutes. If the INR is elevated then clotting times and heparin requirements must be reassessed.

Procedure See page 11 for the equipment list Principle

Rationale

1. Heparin should be checked by 2 Registered Nurses. Both Nurses sign the additive label. 2. Draw up the heparin into the syringe and apply additive label above the level of the plunger. Connect the syringe to the heparin infusion line situated after the arterial pump. Insert with the additive label clearly visible. 3. When access has been established flush the lumen at least five times prior to taking the sample (refer to the guidelines on establishing vascular access). 4. Obtain the baseline blood sample according to the instructions for the actalyke or haemochron equipment.

Drug code of practice Full amount of heparin should be visible to allow for monitoring of the syringe driver. Heparin is infused before the dialyser To prevent contamination of the sample with saline, or heparin if the access is a central line. This enables the nurse to accurately gauge the patient’s response prior to administering any heparin; it also indicates the patients clotting status.

Best Practice The baseline clotting time is the time it takes for non-heparinised blood, taken pre-dialysis, to clot. This baseline is essential as individuals respond differently to the same Principle 5. If the baseline clotting is within normal limits (110-140 seconds) give a Heparin bolus of 500 units into the extracorporeal circuit.

Rationale To prevent clotting within the extracorporeal circuit but not to raise it above 175 seconds.

Best Practice If the baseline clotting time is above or near the upper normal limit (175 Seconds) withhold all heparin and recheck the clotting time within three minutes of commencing extracorporeal treatment. Elevated baseline samples may be due to heparin contamination in patients dialysing with a central venous catheter. Guidelines for Anticoagulation of Extracorporeal Circuits. Revised April 2014. Next revision April 2019.

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If the clotting time remains over 175 seconds withhold heparin until the clotting time is within the normal baseline range and monitor the patients clotting times every 15 minutes. Principle 6. If the base line clotting is within normal limits (110-140 seconds) set the maintenance heparin dose to 0.5 ml/hr and commence treatment as outlined in the specific therapy procedure. 7. Within three to five minutes of commencing treatment take a blood sample from the arterial post of the circuit and recheck the clotting time.

Rationale This allows the effect of the initial bolus to be assessed and to maintain anticoagulation within 175 seconds. It takes three to five minutes for systemic heparinisation to be achieved and the patient’s full response to heparin can be assessed.

At this point the effect of the heparin should be at its optimum level and the response time can be assessed from the baseline clotting time. Principle 8a. If the initial bolus of 0.5ml was insufficient (i.e. clotting time 250mL/min and ideally >300mL/min (unless first dialysis session when a low blood flow rate would normally be prescribed). The blood circuit should be rinsed every 15 – 30 minutes with 25ml – 200ml saline. The ultrafiltration rate should be increased to allow removal of this extra saline. One to one nursing care is required with careful monitoring of the arterial and venous pressure alarms to detect early clotting. Avoid transfusing blood as this will raise the haematocrit and potentially result in the circuit clotting. If significant clotting occurs, flush as much blood back to the patient as possible. Set up and prime new blood lines and dialyser and recommence the treatment if the patient has more than 30 minutes remaining treatment time. If the patient has 30 minutes or less treatment time remaining, clots early in the treatment time, exhibits multiple rapid clotting episodes of the dialysis lines or dialyser or any other indication that heparin free dialysis cannot be successfully accomplished, inform the doctor or Consultant.

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ALTERNATIVE ANTICOAGULANTS TO HEPARIN DANAPAROID Danaparoid is a heparinoid composed of a mixture of low molecular weight glycosaminoglycans. Anticoagulant activity is via antithrombin III, leading to antifactor Xa activity. It is difficult to reverse and monitoring is done via anti Xa levels. Indications for use: 1. Heparin induced thrombocytopenia (acute HIT or previous diagnosis of HIT). 2. Heparin hypersensitivity/allergy. 3. Intolerance of heparin.

Administration Alternate day haemodialysis Danaparoid 3750units bolus (2250units if 55kg 3000 units 2250 units 2000 units 0 units

Danaparoid dose if