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Criteria for extra corporeal life support (ECLS) circuit change

The purpose of these guidelines is to provide a framework to support the extra corporeal life support (ECLS) team in the safe management during a circuit change.

The multiprofessional team involved in the care of the ECLS patient should have an understanding of the physiology of ECLS, familiarity with the ECLS circuit and have reached a recognised level of competence in managing the ECLS patient and prepared to deal with any trouble shooting that may be required.

The criteria for elective circuit change:

  1. A circuit with increasing clot formation affecting performance.  
  2. Visibly developing clots in potentially dangerous locations ie post oxygenator on the arterial limb.
  3. Oxygenator failure, rising premembrane pressures, and poor post oxygenator membrane gases on the Fi02 1.0, pa02 > 15kpa.
  4. Ongoing septicaemia > five days in a patient on ECLS with continual positive blood cultures unresponsive to antibiotics.
  5. Continuous unstable clotting screen caused by consumption of clotting factors by the circuit, with associated clot formation within the ECLS circuit.
The procedure is performed by the following team members:

  • cardiac senior surgical registrar familiar with the procedure
  • Extra Corporeal Membrane Oxygenation (ECMO) physician/fellow, consultant or ECMO coordinator
  • ECMO specialist nurse
  • perfusionist
Note: While this guideline refers to the 'child' throughout, all activities are applicable to young people.

Preparation

  1. Discuss need for a circuit change on the multiprofessional ward round, balancing risks and benefits for the child (Rationale 1). A circuit change will usually extend a child's need for support by up to 48 hours, and they will have exposure to a new circuit and blood products (Rationale 2).
  2. Preparation of the family. Inform the family when this is scheduled to take place including the risks and the benefits. Explain that this is a 'routine' procedure which applies to all children on this type of support. Disconnection of the ECMO circuit takes less than three minutes. They will not be able to stay on the unit during the procedure and this usually takes an hour (Rationale 3).
  3. Contact perfusionists to prime a new circuit / or use a standby system. This usually takes about 40 minutes. Large units of blood will be required for priming to optimise haematocrit (Hct) to 35 (Rationale 4):

    Levitronix centriMag 1/4 x 1/4 circuit: 2 large units
    Levitronix centriMag 1/4 x 3/8 circuit: 2 large units
    Levitronix centriMag 3/8 x 3/8 circuit: 2 large units
  4. Organise a mutually convenient time with the perfusionist, cardiac surgeon and ECMO physician within working hours where possible (Rationale 4).
  5. Prepare the child (Rationale 5).

    Airway - Check endotracheal tube position on chest X-ray (CXR).
    Breathing - Maximise ventilation or hand ventilate. Consider use of nitric oxide.
    Circulation - Attach volume to the child, and prepare any resuscitation drugs and saline flushes (Rationale 6).
    Depending on the reason for ECLS support and the condition of the heart and lungs, other drugs may be required. Adrenaline infusion may be considered in the cardiac child, just prior to the circuit change (Rationale 7).
    Sedation - Ensure that the child is well sedated and/or muscle relaxed for the circuit change (Rationale 8).

    The child should not be demonstrating respiratory effort to reduce the risk of air entraining into the venous cannula during the circuit change.
  6. Check the blood gases and ACT of the circuit prior to the circuit change (Rationale 9). 
  7. At this time the open bridge should be changed to a closed bridge by clamping the bridge with the ECMO clamp and removing the gate clamp and adjusting the blood flow once this procedure has been done. The bridge will now need to be 'flushed' every 15 minutes (Rationale 10).
  8. The actual time the child is off ECLS is a maximum of three minutes, and active resuscitation is therefore, not usually required. Volume resuscitation should be the first line of support. Volume can be removed once the new circuit is attached (Rationale 11).
  9. Document the circuit change in the patients care pathway, electronic patient record, including patients’ vital signs and any drugs or volume given during the procedure (Rationale 12).
  10. Obtain the ECMO priming sheet from the perfusionist and sign for circuit handover.
  11. Check how many units of blood were used. If there are residual units, contact blood bank to have them re-issued if not required (Rationale 13).
  12. Heparin management - be aware how much heparin has been added to prime the new circuit (Rationale 14). For further management see commencing ECLS guideline.
  13. For old circuit follow ECMO cleaning guidelines. 

Rationale

Rationale 1: To provide adequate information for decision making by the multiprofessional team.
Rationale 2: Inflammatory 'cascade' restarts at the change of a circuit.
Rationale 2: To provide information of the procedure to the family to facilitate their understanding of the procedure and the risks and benefits associated with changing the ECLS circuit.
Rationale 3: Enable adequate preparation of personnel and the equipment required for this procedure.
Rationale 4: Safety check to ensure the team are able to provide the child with oxygen and ventilation during the time they are not receiving ECLS.
Rationale 5: Preparation includes the individual needs of the child.
Rationale 6: Resuscitation may be required during the procedure.
Rationale 7: Team prepared to provide Cardiac support if required during the procedure.
Rationale 8: Maintain patient comfort and safety during this procedure.
Rationale 9: Safety check of the new circuit prior to attaching to the patient.
Rationale 10: To avoid clot formation within the bridge.
Rationale 11: To enable quick and efficient re-establishment of ECLS.
Rationale 12: Required for Extracorporeal Life Support Organisation (ELSO) data.
Rationale 13: Efficient use of precious resources.
Rationale 14: Important information in understanding the level of anticoagulation with the circuit

Further reading

Reference 1:
Van Meurs K, Lally KP, Peek G, Zwischenberger JB (2005) ECMO Extracorporeal Cardiopulmonary Support in Critical Care. Ann Arbor Michigan USA, ELSO.

Document control information

Lead author
Maura O'Callaghan, ECMO Co-ordinator, ECMO 

Additional author
Liz Smith, Lead Nurse ANP,  Cardiac
Document owner
Maura O'Callaghan, ECMO Co-ordinator, ECMO 

Approved by
Clinical Practice Committee

First introduced: 19 October 2002
Date approved: 17 May 2012
Review schedule: Two years
Next review: 17 May 2014
Document version: 3.0
Replaces version: 2.0

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