Advanced VV
The ECMO flow drops, the drainage line chatters, and the access pressure becomes increasingly negative.
What is inadequate venous return?
On VA ECMO, an increase in this difference between systolic and diastolic arterial pressure suggests improving native cardiac ejection.
What is pulse pressure?
Because the ECMO pump pulls blood from the patient, pressure between the drainage cannula and the pump normally has this sign.
What is negative pressure?
Unlike ACT or aPTT, this test more directly estimates heparin activity by measuring the inhibition of factor Xa.
What is the heparin assay (or anti-Xa)?
The console goes blank, ECMO flow stops, and the patient turns blue. This backup device can immediately restore circuit flow while the power problem is addressed.
What is the hand crank?
The ECMO flow stays the same, the pulsatility on the arterial line improves and the patients oxygen saturation falls.
What is improving cardiac output?
On peripheral VA ECMO with poor lung function and unchanged circuit flow, a falling patient saturation may indicate improving function of this organ.
What is the heart?
A loose stopcock on this side of the ECMO circuit may spray blood across the room rather than entrain air.
What is the positive-pressure side of the circuit?
This assay dilutes the patient's plasma before adding thrombin, providing a more direct measurement of bivalirudin effect than the aPTT.
What is the dilute Thrombin Time (dTT)?
What are tubing clamps?
On VV ECMO, reducing circuit blood flow shifts more responsibility for oxygenation back to this organ.
What are the lungs?
Reducing VA ECMO blood flow shifts both pumping and oxygenation responsibility back to these two organs.
What are the heart and lungs?
An unchanged ECMO blood flow, the pre-oxygenator pressure rises while the post-oxygenator pressure remains stable, increasing the pressure drop across the oxygenator and suggesting this problem.
What is oxygenator clotting?
For a fresh postoperative cardiac ECMO patient with uncontrolled mediastinal bleeding, this may be the safest initial anticoagulation strategy.
What is temporarily holding systemic anticoagulation?
The bubble alarm sounds and air is visible in the return limb downstream of the oxygenator. This immediate action prevents the air from reaching the patient.
What is clamp the return line between the air and the patient?
This unavoidable VV ECMO phenomenon explains why post-oxygenator blood may be fully saturated while the patient's arterial saturations remain below normal.
What is normal VV mixing?
On femoral VA ECMO, oxygenated circuit blood perfuses the lower body while poorly oxygenated native cardiac output perfuses the upper body - producing 'pink feet and a blue head'.
What is North-South Syndrome?
After repositioning the patient, both pre- and post-oxygenator pressures rise together, while the pressure drop across the oxygenator (TMP) remains unchanged.
What is kinked return tubing / cannula.
When circuit clot burden is increasing and anticoagulation monitoring is below target, this infusion adjustment is generally indicated.
What is increasing the anticoagulation infusion rate?
The patient suddenly becomes hypoxemic and hypercarbic despite unchanged ECMO blood flow and settings. This should be your first circuit check.
What is checking the sweep gas line from its source to the oxygenator.
On VV ECMO, the patient's saturation level falls while the pre-oxygenation saturation rises - narrowing the pre- to post-oxygenator saturation difference.
What is recirculation?
On VA ECMO, a persistently closed aortic valve with LV distension, spontaneous echo contrast, or pulmonary edema should prompt urgent consideration of this intervention.
What is left-heart (LA) decompression?
When pump demand exceeds available venous return, access pressure becomes markedly negative and the drainage tubing visibly shakes or collapses - producing this visible and tactile phenomenon.
What is chatter?
This direct marker of intravascular hemolysis rises when hemoglobin is released from red blood cells into plasma, although lipemia may interfere with its measurement.
What is plasma-free hemoglobin?
Your patient becomes unexpectedly bradycardic and hypothermic to 34 degrees despite stable circuit blood flow. This circuit component and its connections should be checked immediately.
What is the heater-cooler and its water lines?