Q76 / 110
What is the primary role of ultrasound before ECMO initiation?
Correct answer: B — Assess cardiopulmonary function and identify contraindications
Before ECMO, ultrasound helps evaluate ventricular function, valve disease, vascular anatomy, and causes of shock or respiratory failure that may require a different intervention. It can also identify contraindications or conditions that change configuration choice, such as severe aortic regurgitation or tamponade. This makes ultrasound central to initial planning, not just procedural guidance. In modern ECMO care, it is part of the decision framework from the beginning.
Board pearl: Pre-ECMO ultrasound is used to assess candidacy and identify contraindications or reversible alternative diagnoses.
Before ECMO, ultrasound helps evaluate ventricular function, valve disease, vascular anatomy, and causes of shock or respiratory failure that may require a different intervention. It can also identify contraindications or conditions that change configuration choice, such as severe aortic regurgitation or tamponade. This makes ultrasound central to initial planning, not just procedural guidance. In modern ECMO care, it is part of the decision framework from the beginning.
Board pearl: Pre-ECMO ultrasound is used to assess candidacy and identify contraindications or reversible alternative diagnoses.
Q77 / 110
Which imaging modality generally provides the best visualization of cannula position and intracardiac structures during ECMO support?
Correct answer: C — Transesophageal echocardiography
Both transthoracic and transesophageal echocardiography can be useful, but TEE generally provides superior visualization of cardiac chambers, guidewires, and cannulas. This is particularly helpful during cannulation, troubleshooting, and assessment of device position. TTE may still be sufficient in some patients, but image quality is often more limited. For detailed intracardiac views, TEE is usually preferred.
Board pearl: Transesophageal echocardiography usually provides the best visualization of guidewires, cannulas, and cardiac chambers during ECMO management.
Both transthoracic and transesophageal echocardiography can be useful, but TEE generally provides superior visualization of cardiac chambers, guidewires, and cannulas. This is particularly helpful during cannulation, troubleshooting, and assessment of device position. TTE may still be sufficient in some patients, but image quality is often more limited. For detailed intracardiac views, TEE is usually preferred.
Board pearl: Transesophageal echocardiography usually provides the best visualization of guidewires, cannulas, and cardiac chambers during ECMO management.
Q78 / 110
Which finding on pre-ECMO ultrasound is a major contraindication to standard peripheral VA ECMO?
Correct answer: B — Severe aortic regurgitation
Standard VA ECMO increases aortic root pressure and may worsen regurgitation into the left ventricle in severe aortic regurgitation. This can lead to worsening LV distension, pulmonary edema, and ineffective forward support. Pre-ECMO ultrasound is therefore essential to identify this problem before configuration choice. Alternative strategies may be required if support is still needed.
Board pearl: Severe aortic regurgitation is a major contraindication to standard VA ECMO strategies because it can worsen LV distension and regurgitant flow.
Standard VA ECMO increases aortic root pressure and may worsen regurgitation into the left ventricle in severe aortic regurgitation. This can lead to worsening LV distension, pulmonary edema, and ineffective forward support. Pre-ECMO ultrasound is therefore essential to identify this problem before configuration choice. Alternative strategies may be required if support is still needed.
Board pearl: Severe aortic regurgitation is a major contraindication to standard VA ECMO strategies because it can worsen LV distension and regurgitant flow.
Q79 / 110
How does VV ECMO most directly improve right ventricular function in severe ARDS?
Correct answer: B — By reducing pulmonary vascular resistance through improved oxygenation and decarboxylation
In severe ARDS, hypoxemia, hypercapnia, and aggressive ventilator settings can all increase pulmonary vascular resistance and strain the right ventricle. VV ECMO improves gas exchange, often allowing less injurious ventilation and lower RV afterload. This benefit is indirect rather than a direct inotropic effect. The result may be meaningful improvement in RV performance even without arterial support.
Board pearl: VV ECMO can reduce RV afterload by improving oxygenation and CO2 removal, which lowers pulmonary vascular resistance.
In severe ARDS, hypoxemia, hypercapnia, and aggressive ventilator settings can all increase pulmonary vascular resistance and strain the right ventricle. VV ECMO improves gas exchange, often allowing less injurious ventilation and lower RV afterload. This benefit is indirect rather than a direct inotropic effect. The result may be meaningful improvement in RV performance even without arterial support.
Board pearl: VV ECMO can reduce RV afterload by improving oxygenation and CO2 removal, which lowers pulmonary vascular resistance.
Q80 / 110
Which hemodynamic profile best defines vasoplegia during cardiopulmonary bypass?
Correct answer: B — Low mean arterial pressure, normal or high cardiac output, and low systemic vascular resistance
Vasoplegia during bypass is characterized by refractory hypotension with adequate pump flow or cardiac index but markedly reduced systemic vascular resistance. The problem is primarily vascular tone, not insufficient forward flow. This distinguishes it from low-flow states such as pump failure or severe cardiogenic shock. Recognizing the pattern guides rescue therapy.
Board pearl: Vasoplegia is a distributive shock state marked by low systemic vascular resistance despite adequate or high cardiac output.
Vasoplegia during bypass is characterized by refractory hypotension with adequate pump flow or cardiac index but markedly reduced systemic vascular resistance. The problem is primarily vascular tone, not insufficient forward flow. This distinguishes it from low-flow states such as pump failure or severe cardiogenic shock. Recognizing the pattern guides rescue therapy.
Board pearl: Vasoplegia is a distributive shock state marked by low systemic vascular resistance despite adequate or high cardiac output.