1
ECMO SPECIALIST EXAM Actual Exam 2026/2027
Complete Questions and Verified Answers with
Detailed Rationales Section 1 ECMO Specialist
Certification Pass Guaranteed - A+ Graded
Q1: During VA-ECMO initiation, the arterial cannula is typically placed in which vessel for
peripheral access?
A. Internal jugular vein
B. Common femoral artery [CORRECT]
C. Subclavian artery
D. Pulmonary artery
Correct Answer: B
Rationale: The common femoral artery is the standard insertion site for peripheral VA-ECMO
arterial cannulation, providing adequate flow and accessibility while allowing distal limb
perfusion via antegrade cannulation or distal perfusion catheter.
Q2: A patient on VV-ECMO develops sudden hypoxemia with unchanged circuit parameters.
The sweep gas is flowing normally. What is the most likely cause?
A. Pump failure
B. Recirculation [CORRECT]
C. Oxygenator thrombosis
D. Air embolism
Correct Answer: B
Rationale: Recirculation occurs when oxygenated blood is drawn back into the drainage cannula
rather than entering the systemic circulation, causing sudden hypoxemia despite normal circuit
function. This is common with malpositioned cannulas or high flows.
Q3: The optimal activated clotting time (ACT) range for a patient on unfractionated heparin
ECMO anticoagulation is typically:
A. 120-150 seconds
B. 180-220 seconds [CORRECT]
,2
C. 250-300 seconds
D. 350-400 seconds
Correct Answer: B
Rationale: Target ACT for ECMO is typically 180-220 seconds (1.5-2.5 times baseline),
balancing thrombosis prevention with bleeding risk. Higher ranges increase hemorrhagic
complications without proportional benefit.
Q4: During VA-ECMO, a patient develops differential hypoxia (Harlequin syndrome). What is
the pathophysiology?
A. Complete oxygenator failure
B. Native cardiac output competing with ECMO flow causing upper body hypoxemia
[CORRECT]
C. Pump thrombosis
D. Inadequate anticoagulation
Correct Answer: B
Rationale: Differential hypoxia occurs when native cardiac output recovers and competes with
retrograde ECMO flow, creating a mixing point where deoxygenated blood perfuses the coronary
and cerebral circulations while ECMO blood perfuses lower body.
Q5: The oxygenator's gas exchange capability is primarily determined by:
A. Blood flow rate
B. Membrane surface area and gas flow (sweep) rate [CORRECT]
C. Pump speed
D. Cannula diameter
Correct Answer: B
Rationale: Oxygenator efficiency depends on membrane surface area for diffusion and sweep
gas flow rate (FiO₂ and flow) creating the diffusion gradient. Blood flow affects delivery but not
intrinsic gas exchange capability.
Q6: A patient on VV-ECMO has pre-oxygenator SvO₂ of 75% and post-oxygenator saturation of
95%. What does this indicate?
A. Adequate oxygenator function [CORRECT]
B. Oxygenator failure
,3
C. Severe recirculation
D. Inadequate ECMO flow
Correct Answer: B
Rationale: The 20% saturation increase indicates functional oxygenator performance. Normal
VV-ECMO achieves 15-25% saturation increase. Values below 15% suggest oxygenator
dysfunction or excessive recirculation.
Q7: The most common complication of femoral arterial cannulation for VA-ECMO is:
A. Stroke
B. Lower limb ischemia [CORRECT]
C. Pulmonary embolism
D. Aortic dissection
Correct Answer: B
Rationale: Lower limb ischemia occurs in 10-30% of femoral VA-ECMO due to arterial
obstruction. Distal perfusion catheters or antegrade limb perfusion should be considered,
especially with large cannulas (>17 Fr).
Q8: During ECMO transport, if the centrifugal pump stops unexpectedly, the immediate action
is:
A. Increase heparin infusion
B. Manually crank the pump or clamp lines to prevent backflow [CORRECT]
C. Disconnect the oxygenator
D. Decrease sweep gas flow
Correct Answer: B
Rationale: Pump stoppage causes immediate backflow through the circuit. Immediate line
clamping or manual cranking maintains some flow and prevents stagnation/thrombosis until
pump function is restored.
Q9: A patient on VA-ECMO develops rising left atrial pressures and pulmonary edema. What
intervention is indicated?
A. Increase ECMO flow
B. Add mechanical circulatory support (Impella) or convert to central cannulation [CORRECT]
C. Decrease sweep gas FiO₂
D. Remove arterial cannula
, 4
Correct Answer: B
Rationale: Rising left atrial pressure indicates left ventricular distension from inadequate
ventricular unloading. Options include adding Impella, balloon atrial septostomy, or converting
to central cannulation with LA vent.
Q10: The recommended heparin bolus dose for ECMO cannulation is typically:
A. 10-20 units/kg
B. 50-100 units/kg [CORRECT]
C. 300-500 units/kg
D. 1000 units/kg
Correct Answer: B
Rationale: Standard heparin bolus for ECMO cannulation is 50-100 units/kg to achieve adequate
anticoagulation for cannula insertion without excessive bleeding risk. This is followed by
continuous infusion.
Q11: In VV-ECMO, recirculation fraction can be estimated by comparing:
A. Pre-oxygenator and post-oxygenator PaO₂
B. Pre-oxygenator saturation and patient arterial saturation
C. Pre-oxygenator and post-oxygenator oxygen content [CORRECT]
D. Pump speed and patient heart rate
Correct Answer: C
Rationale: Recirculation fraction = (Post-oxygenator O₂ content - Patient arterial O₂ content) /
(Post-oxygenator O₂ content - Pre-oxygenator O₂ content). Values >15-20% indicate significant
recirculation requiring intervention.
Q12: A patient on VA-ECMO has mean arterial pressure of 50 mmHg with adequate ECMO
flow. What is the most appropriate intervention?
A. Increase pump speed
B. Add vasopressors to increase vascular tone [CORRECT]
C. Decrease sweep gas flow
D. Add fluid bolus
Correct Answer: B
Rationale: With adequate ECMO flow (cardiac index >2.2 L/min/m²), hypotension indicates
ECMO SPECIALIST EXAM Actual Exam 2026/2027
Complete Questions and Verified Answers with
Detailed Rationales Section 1 ECMO Specialist
Certification Pass Guaranteed - A+ Graded
Q1: During VA-ECMO initiation, the arterial cannula is typically placed in which vessel for
peripheral access?
A. Internal jugular vein
B. Common femoral artery [CORRECT]
C. Subclavian artery
D. Pulmonary artery
Correct Answer: B
Rationale: The common femoral artery is the standard insertion site for peripheral VA-ECMO
arterial cannulation, providing adequate flow and accessibility while allowing distal limb
perfusion via antegrade cannulation or distal perfusion catheter.
Q2: A patient on VV-ECMO develops sudden hypoxemia with unchanged circuit parameters.
The sweep gas is flowing normally. What is the most likely cause?
A. Pump failure
B. Recirculation [CORRECT]
C. Oxygenator thrombosis
D. Air embolism
Correct Answer: B
Rationale: Recirculation occurs when oxygenated blood is drawn back into the drainage cannula
rather than entering the systemic circulation, causing sudden hypoxemia despite normal circuit
function. This is common with malpositioned cannulas or high flows.
Q3: The optimal activated clotting time (ACT) range for a patient on unfractionated heparin
ECMO anticoagulation is typically:
A. 120-150 seconds
B. 180-220 seconds [CORRECT]
,2
C. 250-300 seconds
D. 350-400 seconds
Correct Answer: B
Rationale: Target ACT for ECMO is typically 180-220 seconds (1.5-2.5 times baseline),
balancing thrombosis prevention with bleeding risk. Higher ranges increase hemorrhagic
complications without proportional benefit.
Q4: During VA-ECMO, a patient develops differential hypoxia (Harlequin syndrome). What is
the pathophysiology?
A. Complete oxygenator failure
B. Native cardiac output competing with ECMO flow causing upper body hypoxemia
[CORRECT]
C. Pump thrombosis
D. Inadequate anticoagulation
Correct Answer: B
Rationale: Differential hypoxia occurs when native cardiac output recovers and competes with
retrograde ECMO flow, creating a mixing point where deoxygenated blood perfuses the coronary
and cerebral circulations while ECMO blood perfuses lower body.
Q5: The oxygenator's gas exchange capability is primarily determined by:
A. Blood flow rate
B. Membrane surface area and gas flow (sweep) rate [CORRECT]
C. Pump speed
D. Cannula diameter
Correct Answer: B
Rationale: Oxygenator efficiency depends on membrane surface area for diffusion and sweep
gas flow rate (FiO₂ and flow) creating the diffusion gradient. Blood flow affects delivery but not
intrinsic gas exchange capability.
Q6: A patient on VV-ECMO has pre-oxygenator SvO₂ of 75% and post-oxygenator saturation of
95%. What does this indicate?
A. Adequate oxygenator function [CORRECT]
B. Oxygenator failure
,3
C. Severe recirculation
D. Inadequate ECMO flow
Correct Answer: B
Rationale: The 20% saturation increase indicates functional oxygenator performance. Normal
VV-ECMO achieves 15-25% saturation increase. Values below 15% suggest oxygenator
dysfunction or excessive recirculation.
Q7: The most common complication of femoral arterial cannulation for VA-ECMO is:
A. Stroke
B. Lower limb ischemia [CORRECT]
C. Pulmonary embolism
D. Aortic dissection
Correct Answer: B
Rationale: Lower limb ischemia occurs in 10-30% of femoral VA-ECMO due to arterial
obstruction. Distal perfusion catheters or antegrade limb perfusion should be considered,
especially with large cannulas (>17 Fr).
Q8: During ECMO transport, if the centrifugal pump stops unexpectedly, the immediate action
is:
A. Increase heparin infusion
B. Manually crank the pump or clamp lines to prevent backflow [CORRECT]
C. Disconnect the oxygenator
D. Decrease sweep gas flow
Correct Answer: B
Rationale: Pump stoppage causes immediate backflow through the circuit. Immediate line
clamping or manual cranking maintains some flow and prevents stagnation/thrombosis until
pump function is restored.
Q9: A patient on VA-ECMO develops rising left atrial pressures and pulmonary edema. What
intervention is indicated?
A. Increase ECMO flow
B. Add mechanical circulatory support (Impella) or convert to central cannulation [CORRECT]
C. Decrease sweep gas FiO₂
D. Remove arterial cannula
, 4
Correct Answer: B
Rationale: Rising left atrial pressure indicates left ventricular distension from inadequate
ventricular unloading. Options include adding Impella, balloon atrial septostomy, or converting
to central cannulation with LA vent.
Q10: The recommended heparin bolus dose for ECMO cannulation is typically:
A. 10-20 units/kg
B. 50-100 units/kg [CORRECT]
C. 300-500 units/kg
D. 1000 units/kg
Correct Answer: B
Rationale: Standard heparin bolus for ECMO cannulation is 50-100 units/kg to achieve adequate
anticoagulation for cannula insertion without excessive bleeding risk. This is followed by
continuous infusion.
Q11: In VV-ECMO, recirculation fraction can be estimated by comparing:
A. Pre-oxygenator and post-oxygenator PaO₂
B. Pre-oxygenator saturation and patient arterial saturation
C. Pre-oxygenator and post-oxygenator oxygen content [CORRECT]
D. Pump speed and patient heart rate
Correct Answer: C
Rationale: Recirculation fraction = (Post-oxygenator O₂ content - Patient arterial O₂ content) /
(Post-oxygenator O₂ content - Pre-oxygenator O₂ content). Values >15-20% indicate significant
recirculation requiring intervention.
Q12: A patient on VA-ECMO has mean arterial pressure of 50 mmHg with adequate ECMO
flow. What is the most appropriate intervention?
A. Increase pump speed
B. Add vasopressors to increase vascular tone [CORRECT]
C. Decrease sweep gas flow
D. Add fluid bolus
Correct Answer: B
Rationale: With adequate ECMO flow (cardiac index >2.2 L/min/m²), hypotension indicates
