Troubleshooting: Chatter:

Chatter describes the erratic swinging movement of the venous drainage cannula. It is analogous to a fire hose being turned on and left to lie on the ground. Some other names for this phenomenon are kicking, rattling, or swinging. Assessing the circuit for chatter is part of basic monitoring of a patient on ECMO.

  • Chatter is caused by a supply-demand mismatch between the pump speed and the blood supply to the pump.
  • The pump creates a negative gradient and tries to "suck" blood from the patient into the circuit.
  • If there isn't enough blood available to flow into the circuit, then the negative pressure relative to the atmosphere causes the circuit to twist and straighten.
  • It is important to distinguish chatter from normal pulsations in the circuit from the patient's cardiac cycle.

If you identify chatter in the circuit, there are a few initial steps you should take:

  • Temporarily lower the RPM of the pump until the chatter resolves.
  • Administer an intravenous fluid bolus appropriate for the given clinical scenario (e.g. crystalloid, albumin, or blood products).
  • Restore the pump speed and see if the chatter persists.

Ongoing chatter despite fluid administration should raise the suspicion of:

  • A kinked or malpositioned drainage cannula causing the vein to collapse, or "suck down"; this can be identified by an x-ray or echocardiography.
    • This is especially common with an Avalon catheter, as the flow is exquisitely sensitive to position and it can chatter very easily.
  • Increased intraabdominal pressure.
  • Increased intrathoracic pressure.
  • Haemorrhage.

Next page: Troubleshooting: Dropping flows

Return to icuECMO Home