1) ECMO Clinical Phases

  • Cannulation: candidate selection, cannula size/flow; lower initial shock severity → earlier weaning.

  • Escalation (24–48h): resuscitate; faster lactate and organ marker clearance → earlier weaning.

  • De-escalation/Weaning: ↓ flows, diurese, ↓ inotropes.

  • Decannulation: echo-guided confirmation, then remove.

2) Plan Exit Early

  • If recovery unlikely: consider LVAD/temporary VADs, VVA/VV ECMO, or palliation.

3) Readiness to Wean

  • Stable MAP, CI, and falling inotropes.

  • Pulse pressure returns/widens.

  • Echo: improving LV/RV function.

  • Perfusion markers: lactate and liver enzymes improving.

  • Tidal CO₂ rise (>5 mmHg) may indicate native circulation returning.

4) Weaning Mechanics

  • Maintain sweep (unlike VV).

  • Gradually reduce ECMO flow (e.g., to 2–2.5 L/min); ensure anticoagulation at low flows.

  • Before destination therapy, assess brain (awakening/CT).

5) Lung Readiness

  • Perform oxygen challenge and ventilation assessment.

  • If heart improves but lungs lag/Harlequin (north–south) appears → consider VVA or VV.

6) Ramp (ECBF Reduction) Study

  • Method: reduce flow ~1 L steps over ~30–45 s; observe hemodynamics + echo.

  • Abort if CVP rises, MAP falls, or instability.

  • Hemodynamic targets: MAP ≥60 mmHg; pulse pressure ≥30 mmHg.

  • Echo targets (at lowest flow):

    1. LVOT VTI >10 cm

    2. EF ≥25%

    3. LV not dilating

    4. Mitral lateral S’ ≥6 cm/s

    5. RV: no dilation or septal shift; coupling helpful

      • S’ / RVSP >1/3 or TAPSE / RVSP >1/2

7) Decannulation Trial

  • Option A: Clamp ECMO ~5 min with echo.

  • Option B: PCRTO (retrograde trial-off) to avoid clotting.

  • If ramp passes: keep low flow (~2 L/min) overnight, then decannulate.

8) If Ramp Fails or Gray Zone

  • Re-optimize (preload/afterload, gas exchange, revascularize, vent LV as needed) and retry.

  • If multi-organ failure: consider one-way decannulation after goals-of-care discussion.

  • If single-ventricle failure persists: bridge to LVAD/transplant.

9) Case Pearls

  • Post-RV infarct: successful wean when RV tolerated preload, AV opened, PP >30, EF ~45%.

  • Post-surgery RV failure: abort ramp if RV dilates/septum shifts at modest flow.

  • Central VA with LV apical vent: clamp RA drainage to test RV; rising LV vent flow indicates readiness to convert ECMO→LVAD, then durable HeartMate 3.

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