ECMO Specialist Exam Actual Exam
2026/2027 – All 101 Questions with
Complete Solutions & Rationales Already
Graded A+ (Instant Download)
Q1: Circuit Monitoring & Troubleshooting
A perfusionist is performing a daily check on a running VV ECMO circuit.
The pre-pump pressure (P1) reads -80 mmHg, and the post-pump pressure
(P2) reads 250 mmHg. The flow is 4.0 L/min. What is the calculated pressure
drop across the oxygenator, and what does this indicate?
A. The pressure drop is 170 mmHg, indicating a possible clot in the heat
exchanger.
B. The pressure drop is 330 mmHg, indicating immediate pump head
failure.
C. The pressure drop is 170 mmHg, which is within normal limits for full
flow.
D. The pressure drop is 80 mmHg, indicating hypovolemia requiring fluid
bolus.
Correct Answer: C
Rationale: The pressure drop (ΔP) across the oxygenator is calculated as
Post-pump pressure minus Pre-oxygenator pressure. A ΔP of 170 mmHg at
4.0 L/min is typically within normal limits for a modern polymethylpentene
(PMP) oxygenator, whereas a rising gradient (approaching 300+ mmHg)
would indicate clotting. Hypovolemia is indicated by highly negative P1
pressures, not the ΔP .
,Q2: Emergency Procedures & Physics
During an emergency power loss, the ECMO specialist initiates hand-
cranking of the centrifugal pump. Which physical principle dictates that the
specialist must maintain the correct rotational direction and speed to
prevent massive hemolysis?
A. Bernoulli's Principle.
B. Reynolds' Number.
C. Shear stress mechanics.
D. Poiseuille's Law.
Correct Answer: C
Rationale: Hand-cranking too fast or too slow creates abnormal shear
stress forces on the blood components. Excessive speed causes high shear
stress, leading to immediate hemolysis. Poiseuille's law governs flow
resistance in tubes, while Bernoulli relates to fluid speed and pressure.
Maintaining the correct RPM range ensures the pump impeller creates
kinetic energy without excessive friction on the blood elements .
Q3: Cannulation & Recirculation
A patient on VV ECMO has a dual-lumen catheter (e.g., Avalon/ProtekDuo)
inserted in the right internal jugular vein. The drainage lumen ports are
located in the IVC and SVC, while the return lumen port is positioned in the
RA. If the tip migrates into the IVC, what is the primary physiologic
consequence?
A. Increased afterload on the right ventricle.
B. Decreased circuit flow due to high resistance.
C. Increased recirculation fraction.
D. Differential hypoxia (Harlequin syndrome).
Correct Answer: C
Rationale: If the dual-lumen catheter tip migrates such that the return port
(directing oxygenated blood) is positioned close to the drainage ports
(usually the SVC/IVC ports), the freshly oxygenated blood is immediately re-
,aspirated into the drainage lumen. This "recirculation" reduces effective
systemic oxygen delivery. Differential hypoxia is a complication of VA
ECMO, not VV ECMO .
Q4: Circuit Design & Safety
Which component of the ECMO circuit is specifically designed to minimize
the risk of gas embolism during a membrane breach by utilizing a
microporous hydrophobic layer?
A. The integral heat exchanger.
B. The plasma-tight hollow fiber membrane.
C. The arterial line filter.
D. The venous bubble trap.
Correct Answer: B
Rationale: Modern PMP (polymethylpentene) oxygenators use plasma-
tight hollow fibers. While older microporous membranes had a risk of
plasma leakage, the structure is designed to separate the gas phase from
the blood phase. The "true" safety feature preventing gas entry into blood
during a breach relies on the pressure gradient (blood pressure > gas
pressure). However, regarding the material composition, the plasma-tight
nature prevents plasma wetting of the micropores which would lead to gas
exchange failure .
Q5: Pharmacology & Anticoagulation
Why is anticoagulation necessary for a patient on ECMO?
A. To prevent bleeding from surgical sites.
B. To counteract the SIRS response.
C. To prevent clot formation from blood contact with the circuit.
D. To treat underlying sepsis.
, Correct Answer: C
Rationale: Blood contact with the foreign surfaces of the ECMO circuit
activates the coagulation cascade and the systemic inflammatory response
(SIRS), leading to a high risk of thrombosis. Anticoagulation, typically with
heparin, is required to prevent clot formation within the circuit and in the
patient .
Q6: Oxygenator Performance
During a VV ECMO run, the sweep gas flow is set at 4 L/min with 100%
FiO₂. The post-oxygenator pO₂ is 450 mmHg and pCO₂ is 35 mmHg. If the
sweep gas flow is decreased to 1 L/min, what immediate change would you
expect?
A. Increased post-oxygenator pO₂ and decreased pCO₂.
B. Decreased post-oxygenator pO₂ and increased pCO₂.
C. No change in either pO₂ or pCO₂.
D. Increased pCO₂ only, with no change in pO₂.
Correct Answer: B
Rationale: Sweep gas flow regulates CO₂ removal (diffusion-limited).
Decreasing sweep flow reduces the concentration gradient for CO₂
washout, leading to hypercapnia. Oxygen transfer is primarily affected by
blood flow and the oxygenator's surface area, not sweep gas flow, once the
blood is fully saturated. However, at very low sweep flows, pO₂ may also
drop slightly due to reduced oxygen delivery into the gas phase .
Q7: Mechanical Complications
The ECMO circuit alarms with a high pre-pump pressure (P1) reading of -
200 mmHg. The flow has dropped from 4.0 L/min to 2.5 L/min. What is the
MOST likely cause?
A. Patient hypertension.
B. Oxygenator clotting.
C. Inflow obstruction (e.g., cannula malposition or hypovolemia).
D. Clamp partially closed on the return line.
2026/2027 – All 101 Questions with
Complete Solutions & Rationales Already
Graded A+ (Instant Download)
Q1: Circuit Monitoring & Troubleshooting
A perfusionist is performing a daily check on a running VV ECMO circuit.
The pre-pump pressure (P1) reads -80 mmHg, and the post-pump pressure
(P2) reads 250 mmHg. The flow is 4.0 L/min. What is the calculated pressure
drop across the oxygenator, and what does this indicate?
A. The pressure drop is 170 mmHg, indicating a possible clot in the heat
exchanger.
B. The pressure drop is 330 mmHg, indicating immediate pump head
failure.
C. The pressure drop is 170 mmHg, which is within normal limits for full
flow.
D. The pressure drop is 80 mmHg, indicating hypovolemia requiring fluid
bolus.
Correct Answer: C
Rationale: The pressure drop (ΔP) across the oxygenator is calculated as
Post-pump pressure minus Pre-oxygenator pressure. A ΔP of 170 mmHg at
4.0 L/min is typically within normal limits for a modern polymethylpentene
(PMP) oxygenator, whereas a rising gradient (approaching 300+ mmHg)
would indicate clotting. Hypovolemia is indicated by highly negative P1
pressures, not the ΔP .
,Q2: Emergency Procedures & Physics
During an emergency power loss, the ECMO specialist initiates hand-
cranking of the centrifugal pump. Which physical principle dictates that the
specialist must maintain the correct rotational direction and speed to
prevent massive hemolysis?
A. Bernoulli's Principle.
B. Reynolds' Number.
C. Shear stress mechanics.
D. Poiseuille's Law.
Correct Answer: C
Rationale: Hand-cranking too fast or too slow creates abnormal shear
stress forces on the blood components. Excessive speed causes high shear
stress, leading to immediate hemolysis. Poiseuille's law governs flow
resistance in tubes, while Bernoulli relates to fluid speed and pressure.
Maintaining the correct RPM range ensures the pump impeller creates
kinetic energy without excessive friction on the blood elements .
Q3: Cannulation & Recirculation
A patient on VV ECMO has a dual-lumen catheter (e.g., Avalon/ProtekDuo)
inserted in the right internal jugular vein. The drainage lumen ports are
located in the IVC and SVC, while the return lumen port is positioned in the
RA. If the tip migrates into the IVC, what is the primary physiologic
consequence?
A. Increased afterload on the right ventricle.
B. Decreased circuit flow due to high resistance.
C. Increased recirculation fraction.
D. Differential hypoxia (Harlequin syndrome).
Correct Answer: C
Rationale: If the dual-lumen catheter tip migrates such that the return port
(directing oxygenated blood) is positioned close to the drainage ports
(usually the SVC/IVC ports), the freshly oxygenated blood is immediately re-
,aspirated into the drainage lumen. This "recirculation" reduces effective
systemic oxygen delivery. Differential hypoxia is a complication of VA
ECMO, not VV ECMO .
Q4: Circuit Design & Safety
Which component of the ECMO circuit is specifically designed to minimize
the risk of gas embolism during a membrane breach by utilizing a
microporous hydrophobic layer?
A. The integral heat exchanger.
B. The plasma-tight hollow fiber membrane.
C. The arterial line filter.
D. The venous bubble trap.
Correct Answer: B
Rationale: Modern PMP (polymethylpentene) oxygenators use plasma-
tight hollow fibers. While older microporous membranes had a risk of
plasma leakage, the structure is designed to separate the gas phase from
the blood phase. The "true" safety feature preventing gas entry into blood
during a breach relies on the pressure gradient (blood pressure > gas
pressure). However, regarding the material composition, the plasma-tight
nature prevents plasma wetting of the micropores which would lead to gas
exchange failure .
Q5: Pharmacology & Anticoagulation
Why is anticoagulation necessary for a patient on ECMO?
A. To prevent bleeding from surgical sites.
B. To counteract the SIRS response.
C. To prevent clot formation from blood contact with the circuit.
D. To treat underlying sepsis.
, Correct Answer: C
Rationale: Blood contact with the foreign surfaces of the ECMO circuit
activates the coagulation cascade and the systemic inflammatory response
(SIRS), leading to a high risk of thrombosis. Anticoagulation, typically with
heparin, is required to prevent clot formation within the circuit and in the
patient .
Q6: Oxygenator Performance
During a VV ECMO run, the sweep gas flow is set at 4 L/min with 100%
FiO₂. The post-oxygenator pO₂ is 450 mmHg and pCO₂ is 35 mmHg. If the
sweep gas flow is decreased to 1 L/min, what immediate change would you
expect?
A. Increased post-oxygenator pO₂ and decreased pCO₂.
B. Decreased post-oxygenator pO₂ and increased pCO₂.
C. No change in either pO₂ or pCO₂.
D. Increased pCO₂ only, with no change in pO₂.
Correct Answer: B
Rationale: Sweep gas flow regulates CO₂ removal (diffusion-limited).
Decreasing sweep flow reduces the concentration gradient for CO₂
washout, leading to hypercapnia. Oxygen transfer is primarily affected by
blood flow and the oxygenator's surface area, not sweep gas flow, once the
blood is fully saturated. However, at very low sweep flows, pO₂ may also
drop slightly due to reduced oxygen delivery into the gas phase .
Q7: Mechanical Complications
The ECMO circuit alarms with a high pre-pump pressure (P1) reading of -
200 mmHg. The flow has dropped from 4.0 L/min to 2.5 L/min. What is the
MOST likely cause?
A. Patient hypertension.
B. Oxygenator clotting.
C. Inflow obstruction (e.g., cannula malposition or hypovolemia).
D. Clamp partially closed on the return line.
