The purpose of this guideline is to provide a framework to support the extra corporeal life support (ECLS) team in the safe management of converting a child from veno-venous (VV) to veno-arterial (VA) extra corporeal membrane oxygenation (ECMO) support.
Background
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.
Note: While this guideline refers to the ‘child’ throughout, all activities are applicable to young people.
VV ECMO support requires good native heart function (
Rationale 1).
Reasons for conversion:
- Inability to maintain adequate oxygen delivery to tissues (unable to oxygenate, metabolic acidosis). Confirm adequate blood flow through VV cannula on ECHO.
- Inability to maintain blood pressure/perfusion despite volume and inotropes, and optimisation of VV ECMO.
- Poor cardiac function.
The decision to convert from VV to VA ECLS made by the ECMO physician.
- Personnel required:
Cardiac surgeon, scrub nurse, perfusionist (Rationale 2).
ECMO specialist nurse, ECMO fellow/intensivist (Rationale 3) - Cannula size: Decide on the size of the venous and arterial cannula to be used. Assess patient stability throughout the procedure (Rationale 4).
- Clotting: Check the clotting screen prior to procedure (Rationale 5).
- Parents: Discuss with the patents the reason for the procedure to be undertaken and the associated risks (Rationale 6).
- Cooling: Cooling should be used to 34°C, with sedation and muscle relaxants for the procedure to assist with cerebral protection. An oesophageal temperature probe should be used to monitor central temperature.
- Prepare the child for a surgical procedure, ie position, availability of lines, emergency drugs, cross matched blood available on the unit (Rationale 7). Volume, colloid or blood already drawn up in 50cc syringe and attached to the child via a long line (Rationale 8).
Fentanyl - 5-10mcg/kg
Rocuronium - 0.5-1.0mg/kg (unless renal failure - use atracurium)
Vecuronium - 0.1mg/kg
Sodium Chloride 0.9% - 5ml x 3
Heparin - 50 units/kg - The child will require a cut down procedure to insert the arterial cannula – all equipment for the procedure to be supplied by the theatre team.
- The child will need to come off ECLS support briefly for recannulation of the internal jugular vein (IJV) and re connection of the venous and arterial cannula to the circuit.
Conversion from double lumen VV cannula will require both arterial cannula and a new single lumen venous cannula. Continued use of the double lumen cannula usually results in thrombus formation in one of the lumens. - Prophylactic antibiotics to be prescribed and given for 24 hours (BNF for Children 2011; GOSH antibiotic guidelines 2010) (Rationale 9).
| Antibiotic | Dosage |
| Flucloxacillin | - neonates < 7 days - 25mg/kg, 12-hourly
- neonates 7 - 21 days - 25mg/kg, eight-hourly
- 21 days to 18 years - 25mg/kg, six-hourly
|
| Amikacin | - neonates < 28 days, 15mg/kg, one dose only (for patients <2kg consult GOSH antibiotic policy)
- 28 days to 18 years - 15mg/kg two doses
- renal impairment - 10mg/kg, one dose only
|
Teicoplanin (if already on antibiotics)
| - neonates - 16mg/kg dose for initial 24 hours
- 28 days to 18 years - 10mg/kg (max 400mg every 12 hours) for two doses
|
Prophylactic antibiotics and recommended dosages
If unsure please consult with the clinician leading the care of the baby/child.
10. Anaesthesia:
The child is anaesthetised with Fentanyl and muscle relaxation is maintained with Rocuronium/Vecuronium.
Ensure good access to airway, hand ventilation tubing long enough to reach the baby and attach to nitric oxide if required.
11. Venous access:
Adequate venous access is essential, preferably central but not essential if there is good peripheral access. Extension lines are to clear surgical field.
Ensure emergency volume is drawn up and ready for use, and emergency drugs are at the bedside. Blood should be available if needed (Rationale 10).
Discuss with surgeon whether a half dose of heparin (50units/kg) is required for cannulation (Rationale 11).
12. End of conversion:
Check that full blood flow can be achieved up to 120% (Rationale 12).
Document size of new cannula.
Check that the circuit is correctly connected: venous cannula to venous limb of the circuit and arterial cannula to arterial limb (trace back to the oxygenator) (Rationale 13).
Rationale 1: VV ECMO does not provide direct cardiac support but replaces pulmonary gas exchange and therefore theoretically offers indirect cardiac support.
Rationale 2: Surgical procedure.
Rationale 3: To maintain life support during the procedure and re-establish ECMO support following conversion.
Rationale 4: Ensure appropriate size cannula available, surgical decision on the size used, made once the vessels have been visualised.
Rationale 5: To minimise further risk of bleeding in a patient receiving anticoagulation therapy.
Rationale 6: To keep the parents fully informed of treatment procedures.
Rationale 7: To provide appropriate analgesia and anaesthetic cover for the procedure.
Rationale 8: Team prepared for emergency fluid resuscitation.
Rationale 9: Prophylactic antibiotic cover to prevent infection.
Rationale 10: Team prepared for emergency resuscitation.
Rationale 11: To prevent clot formation in the cannulae.
Rationale 12: Safety check: ECMO support can be re-established before the surgical team leave the bedside.
Rationale 13: Safety check: providing correct ECMO support.
Reference 1:
van Meurs K, Lally KP, Peek G (2005) ECMO Extracorporeal Cardiopulmonary Support in Criical Care. Ann Arbor Michigan, ELSO.
Reference 2:
Fortenberry JD, Pettignano R, Dykes F (2005) Principles and Practice of Venovenous ECMO Van Meurs K Lally KP Peek G Zwischenberger JB in: ECMO Extracorporeal Cardiopulmonary Support in Critical Care. Ann Arbor Michigan USA, ELSO.
Reference 3:
British National Formulary (2012) BNF for Children 2011-2012. London, BMJ Publishing Group Ltd, RCPCH Publications Ltd and Royal Pharmaceutical Society of Great Britain
Document control information
Lead authorMaura O'Callaghan, ECMO Co-ordinator, ECMO
Additional authorLiz Smith, Lead Nurse ANP, ECMO
Document owner
Maura O'Callaghan, ECMO Co-ordinator, ECMO
Approved by
Cho Ng, Lead Consultant ECMO, CICU/ECMO
First introduced: 5 July 1999
Date approved: 25 April 2012
Review schedule: Two years
Next review: 25 April 2014
Document version: 4.0
Replaces version: 3.0
