CES ECMO Weaning & Decannulation 3 — Questions and Answers
Question 1: The 'ECMO-off' test in VV ECMO involves which specific maneuver?
- Reducing flow to 0.5 L/min for 10 minutes
- Clamping both the drainage and return limbs with the circuit recirculating for 5–10 minutes while monitoring gases (Correct answer)
- Removing the patient from the circuit entirely for 1 hour
- Increasing FiO2 on the ventilator to 1.0 during flow reduction
Correct answer: Clamping both the drainage and return limbs with the circuit recirculating for 5–10 minutes while monitoring gases
Clamping both ECMO limbs while recirculating allows assessment of native lung gas exchange without any ECMO support for a brief trial period.
Question 2: Which ventilator strategy is recommended before attempting VV ECMO weaning to protect the recovering lung?
- High PEEP and low tidal volume (lung-protective ventilation) (Correct answer)
- High tidal volume to re-recruit atelectasis
- Pressure control with high FiO2
- Spontaneous breathing mode without PEEP
Correct answer: High PEEP and low tidal volume (lung-protective ventilation)
Lung-protective ventilation with low tidal volumes and appropriate PEEP should be confirmed adequate before and during weaning to prevent re-injury.
Question 3: After successful ECMO weaning, anticoagulation is typically:
- Continued at full therapeutic doses for 48 hours post-decannulation
- Discontinued immediately at decannulation
- Transitioned to prophylactic dosing or bridged to oral anticoagulation based on indication (Correct answer)
- Maintained with heparin drip for one week
Correct answer: Transitioned to prophylactic dosing or bridged to oral anticoagulation based on indication
Post-decannulation anticoagulation is individualized — prophylactic dosing or bridging to oral agents is common depending on thrombosis risk and bleeding history.
Question 4: What echo parameter during a VA ECMO weaning trial at 1 L/min flow best predicts successful decannulation?
- LVEF > 35% and LVOT VTI > 12 cm (Correct answer)
- Heart rate < 60 bpm
- Right ventricular fractional area change > 40%
- Pulmonary artery systolic pressure < 25 mmHg
Correct answer: LVEF > 35% and LVOT VTI > 12 cm
LVEF > 35% combined with LVOT VTI > 12 cm at minimal ECMO support correlates with sufficient cardiac recovery for decannulation.
Question 5: Which parameter indicates successful weaning from neonatal VV ECMO in a term infant?
- PaO2 > 60 mmHg on FiO2 0.4 with sweep gas off (Correct answer)
- Normal chest X-ray appearance
- Absence of supplemental oxygen requirement
- Heart rate < 120 bpm
Correct answer: PaO2 > 60 mmHg on FiO2 0.4 with sweep gas off
Maintaining PaO2 > 60 mmHg on FiO2 ≤ 0.4 with sweep gas turned off demonstrates sufficient native lung recovery in neonates.
Question 6: Which surgical technique is used for decannulation when the femoral artery requires patch repair?
- Primary closure with 4-0 Prolene suture only
- Vein patch angioplasty or synthetic patch closure to prevent stenosis (Correct answer)
- Ligation of the femoral artery
- Endovascular stent placement immediately
Correct answer: Vein patch angioplasty or synthetic patch closure to prevent stenosis
When primary closure would narrow the femoral artery, vein patch angioplasty or a synthetic patch is used to maintain vessel patency.
CES ECMO Weaning & Decannulation 3
The 'ECMO-off' test in VV ECMO involves which specific maneuver?