CES ECMO Complications & Management 2 — Questions and Answers
Question 1: Retroperitoneal hematoma during ECMO is most often related to:
- Over-anticoagulation combined with femoral cannulation (Correct answer)
- Oxygenator rupture
- Surgical cannulation via neck vessels
- Spontaneous bleeding from anticoagulation alone
Correct answer: Over-anticoagulation combined with femoral cannulation
Retroperitoneal hematoma frequently results from a combination of anticoagulation and femoral access, especially if the access wire or cannula traverses the posterior peritoneum.
Question 2: Oxygenator thrombosis is first suspected when:
- Blood pressure suddenly drops
- Transmembrane pressure gradient across the oxygenator acutely rises (Correct answer)
- Circuit flow spontaneously increases
- Venous limb oxygen saturation falls below 60%
Correct answer: Transmembrane pressure gradient across the oxygenator acutely rises
A rising transmembrane pressure gradient (pre- vs. post-oxygenator pressure difference) indicates increasing resistance from thrombus formation within the oxygenator.
Question 3: Which anticoagulation monitoring approach is recommended when heparin-induced thrombocytopenia (HIT) is suspected on ECMO?
- Increase heparin dose and monitor anti-Xa levels
- Discontinue heparin and transition to bivalirudin, monitoring aPTT or ACT (Correct answer)
- Switch to warfarin immediately
- Administer argatroban with anti-Xa monitoring
Correct answer: Discontinue heparin and transition to bivalirudin, monitoring aPTT or ACT
Bivalirudin is the preferred anticoagulant when HIT is suspected or confirmed during ECMO, monitored via aPTT or ACT.
Question 4: Massive air embolism in the ECMO circuit requires immediate:
- Increasing ECMO flow to dilute the air
- Clamping the circuit and placing the patient in Trendelenburg position (Correct answer)
- Administering 100% FiO2 only
- Decreasing sweep gas to prevent further air entrainment
Correct answer: Clamping the circuit and placing the patient in Trendelenburg position
Clamping the circuit to prevent air delivery to the patient plus Trendelenburg positioning to trap air in the right side is the immediate response to massive air embolism.
Question 5: Left ventricular distension during VA ECMO is caused by:
- Excessive circuit blood flow returning to the right heart
- Increased left ventricular afterload from retrograde aortic flow combined with poor LV ejection (Correct answer)
- Low sweep gas flow reducing oxygenation
- Right heart failure from elevated pulmonary pressures
Correct answer: Increased left ventricular afterload from retrograde aortic flow combined with poor LV ejection
Retrograde VA ECMO flow increases LV afterload; if the LV cannot eject against this pressure, the ventricle distends, worsening myocardial recovery.
Question 6: Which intervention is used to vent the distended left ventricle during VA ECMO?
- Increasing ECMO flow rate
- Intra-aortic balloon pump (IABP) or Impella device to offload the LV (Correct answer)
- Decreasing vasopressor doses only
- Adding a venous limb to convert to VAV ECMO
Correct answer: Intra-aortic balloon pump (IABP) or Impella device to offload the LV
An IABP or Impella device provides mechanical left ventricular unloading, reducing wall stress and enabling myocardial recovery during VA ECMO.
CES ECMO Complications & Management 2
Retroperitoneal hematoma during ECMO is most often related to: