Intra-aortic balloon pumps, ECMO, and ventricular assist devices, including indications and basic management principles.
34 cards · basic cards · AI-written, checked twice. Edit anything.
- What is the primary mechanism by which an intra-aortic balloon pump (IABP) augments the circulation?
- Counterpulsation: the balloon inflates during diastole to boost coronary perfusion and deflates just before systole to reduce afterload
- Where is the tip of a correctly positioned intra-aortic balloon typically located?
- In the descending thoracic aorta, just distal to the origin of the left subclavian artery
- What gas is used to inflate an intra-aortic balloon?
- Helium, because of its low viscosity and rapid diffusion characteristics
- What ECG or pressure waveform feature is commonly used to time IABP inflation?
- The dicrotic notch on the arterial pressure waveform, corresponding to aortic valve closure
- What hemodynamic effect does correctly timed IABP deflation have just before systole?
- It reduces left ventricular afterload, lowering myocardial oxygen demand and improving forward stroke volume
- Name a major contraindication to intra-aortic balloon pump use.
- Significant aortic insufficiency (or severe aortic disease such as dissection or significant aneurysm)
- What does the acronym ECMO stand for?
- Extracorporeal membrane oxygenation
- What are the two main configurations of ECMO based on cannulation?
- Venovenous (VV) ECMO and venoarterial (VA) ECMO
- What is the primary purpose of venovenous (VV) ECMO?
- Providing respiratory support (gas exchange) in patients with severe respiratory failure but adequate cardiac function
- What is the primary purpose of venoarterial (VA) ECMO?
- Providing both cardiac and respiratory support in patients with combined cardiac and respiratory failure or cardiogenic shock
- Why does VV ECMO not provide direct hemodynamic (cardiac output) support?
- Blood is returned to the venous system rather than the arterial system, so it does not bypass or directly assist the failing heart
- What complication is specific to peripheral VA ECMO where the native heart still ejects some blood against retrograde arterial flow?
- Differential hypoxia (Harlequin syndrome), where poorly oxygenated blood from the native heart preferentially perfuses the upper body
- What is often placed distal to a femoral arterial ECMO cannula to prevent limb ischemia?
- A distal limb reperfusion cannula (distal perfusion catheter)
- What is the general purpose of a ventricular assist device (VAD)?
- Mechanically augmenting or replacing the pumping function of a failing ventricle to maintain adequate systemic or pulmonic circulation
- What are the three general clinical intent categories for VAD implantation?
- Bridge to transplant, bridge to recovery, and destination therapy
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