This is failure of either the drive console or pump head to drive the centrifugal pump and create forward circuit blood flow. ECMO support will stop.
VA ECMO: if the circulation is largely supported by ECMO flow, this will be associated with haemodynamic collapse and retrograde circuit flow. If reasonable native cardiac function exists, varying degrees of hypotension and cardiogenic shock will occur.
VV ECMO: if highly dependent on ECMO blood flow, dramatic desaturation and cardiac arrest can occur within seconds
- Pump head disengagement or fulminant thrombosis
- Electrical motor failure – either console or pump head
- Battery failure (and no AC power connected)
- Rotaflow Power Isolation Switch “OFF”
- Clamp circuit
- Call for help. Contact ICU Consultant and ECLS Coordinator
- Ask for emergency console
Engage Emergency Drive Unit (“Hand-crank”)
- Transfer pump head to Emergency Drive Unit
- If visible air or thrombus in pump head – ask for emergency circuit with emergency exchange pack and change circuit
- Otherwise rotate hand crank to 1500 rpm and remove circuit clamp
- Increase revs to previous speed if known or 3000 rpm
Ask for emergency console – Differentiate between power failure and pump head thrombosis
- Console (front): Power (On/Off Switch)
- Console (front): AC Power Supply Indicator lights
- Console (rear): Power Isolation Switch
Transfer to new console
- Ensure power to new console
- Clamp circuit
- Transfer pump head to a new console
- Establish pump speed to 1500 rpm and remove circuit clamp over 3-5 seconds while increasing pump speed to obtain full flow
Pump head thrombosis
In pump head thrombosis, thrombus is caught in the pump head with associated drop in blood flow to varying degrees. This may be from a clot that has been aspirated through the access cannula or formed within the cannula or circuit.
There can be a wide range of effects from pump head thrombosis ranging from standstill of the pump, rapidly enlarging clot to thrombus that barely interferes with the pump function.
Regardless of the presentation, a timely circuit change is indicated upon identification of the pump head thrombosis
Key features for early recognition
- Pump head noise, vibration
- Drop in blood flow
If a pump head thrombosis is suspected, the circuit should be examined to find evidence of thrombus. This can be subtle at times. See the examples below.