ECMO Weaning and Decannulation 5 — Questions and Answers
Question 1: Which combination of ventilator settings during a VV-ECMO weaning trial most closely mimics conditions the patient will face after decannulation?
- High PEEP (15 cmH2O), low FiO2 0.21, sweep off
- Protective lung settings (FiO2 ≤ 0.40, PEEP 8–10 cmH2O) with sweep gas off (Correct answer)
- Apnea test settings (zero rate, no PS) with sweep gas on
- Pressure-controlled ventilation at full FiO2 1.0 with sweep on
Correct answer: Protective lung settings (FiO2 ≤ 0.40, PEEP 8–10 cmH2O) with sweep gas off
Protective ventilation at low FiO2 with sweep off simulates post-decannulation conditions, revealing whether the lungs can sustain gas exchange independently.
Question 2: A previously anticoagulated ECMO patient requires decannulation but has an INR of 3.2 and platelet count of 45,000/µL. What is the most appropriate preparatory step?
- Proceed immediately; coagulopathy does not affect surgical decannulation safety
- Correct coagulopathy with fresh frozen plasma and platelets before decannulation, targeting INR < 1.5 and platelets > 80,000/µL (Correct answer)
- Administer protamine alone and proceed to decannulation
- Delay decannulation for 7 days until coagulopathy resolves spontaneously
Correct answer: Correct coagulopathy with fresh frozen plasma and platelets before decannulation, targeting INR < 1.5 and platelets > 80,000/µL
Correcting coagulopathy before decannulation reduces the risk of life-threatening hemorrhage at cannula removal sites.
Question 3: Which clinical sign during a VA-ECMO low-flow weaning trial indicates right ventricular failure and should prompt aborting the trial?
- Widened pulse pressure on the arterial waveform
- Rising central venous pressure with hepatomegaly and worsening systemic hypotension (Correct answer)
- Sinus tachycardia at 100 bpm
- Mild decrease in urine output from 80 to 60 mL/hr
Correct answer: Rising central venous pressure with hepatomegaly and worsening systemic hypotension
Elevated CVP with hepatomegaly and systemic hypotension during flow reduction signals right ventricular failure, mandating return to full ECMO support.
Question 4: In the context of ECMO weaning, what does the term 'circuit holiday' refer to?
- Planned temporary cessation of anticoagulation to reduce bleeding risk
- A brief period of complete ECMO flow cessation (with circuit clamping) to assess native cardiopulmonary function (Correct answer)
- Scheduled circuit change to prevent membrane oxygenator failure
- Reduction in sweep gas to the minimum possible level for 24 hours
Correct answer: A brief period of complete ECMO flow cessation (with circuit clamping) to assess native cardiopulmonary function
A circuit holiday (clamp trial) briefly stops all ECMO flow with the circuit clamped to evaluate whether native heart and lung function can sustain the patient.
Question 5: Following decannulation from femoral VA-ECMO, a patient develops ipsilateral leg swelling and pain. Duplex ultrasound reveals deep vein thrombosis at the cannulation site. Appropriate management includes:
- Surgical thrombectomy immediately
- Therapeutic anticoagulation and monitoring for pulmonary embolism (Correct answer)
- Observation alone; cannulation-site DVT never embolizes
- Inferior vena cava filter placement as the first-line intervention
Correct answer: Therapeutic anticoagulation and monitoring for pulmonary embolism
Cannulation-site DVT is managed with therapeutic anticoagulation and surveillance for PE, similar to other lower-extremity DVT.
Question 6: After decannulation from VV-ECMO, the patient develops hoarseness and difficulty swallowing. The most likely etiology related to the ECMO procedure is:
- Phrenic nerve injury from left internal jugular cannulation
- Recurrent laryngeal nerve injury or vocal cord dysfunction related to right internal jugular cannulation (Correct answer)
- Tracheal stenosis from prolonged intubation
- Esophageal perforation during transesophageal echocardiography
Correct answer: Recurrent laryngeal nerve injury or vocal cord dysfunction related to right internal jugular cannulation
The recurrent laryngeal nerve passes near the right internal jugular vein and can be injured during cannulation or decannulation, causing hoarseness.
Question 7: Which statement correctly describes the role of intra-aortic balloon pump (IABP) in VA-ECMO weaning?
- IABP increases ECMO afterload and should never be used concurrently
- IABP provides additional LV unloading and hemodynamic support to facilitate ECMO weaning in borderline candidates (Correct answer)
- IABP is contraindicated in patients with femoral arterial ECMO cannulas
- IABP replaces the need for echocardiographic assessment during the weaning trial
Correct answer: IABP provides additional LV unloading and hemodynamic support to facilitate ECMO weaning in borderline candidates
IABP augments diastolic coronary perfusion and reduces LV afterload, serving as a bridge device to facilitate VA-ECMO weaning in patients with marginal ventricular recovery.
ECMO Weaning and Decannulation 5
Which combination of ventilator settings during a VV-ECMO weaning trial most closely mimics conditions the patient will face after decannulation?