VA-ECMO Monitoring — Summary
Purpose & Setup
- Context: Peripheral VA-ECMO: venous drainage → pump → oxygenator/heater → arterial return (often femoral) ± distal perfusion cannula to protect the limb.
- Goals: Hemodynamic stabilization, detect myocardial recovery, ensure systemic perfusion, and early complication detection via a multidisciplinary team.
Two-Pronged Monitoring
- Patient: Hemodynamics, perfusion, neuro, respiratory, renal/metabolic, hematology.
- Circuit: Flows, pressures, gas exchange, integrity, limb perfusion.
Hemodynamics & Perfusion
- Core tools: ECG, arterial line, CVP, ± pulmonary artery catheter, echo, advanced monitors (PiCCO).
- Targets: MAP ≥65 mmHg, cardiac index ≥2.2 L/min/m², CVP <15 mmHg.
- Perfusion indices: Pulsatility (aortic valve opening), SvO₂, lactate, end-tidal CO₂, chest X-ray for pulmonary edema (LV distension), echo for LV/LA pressures.
Neurologic Surveillance
- Methods: Serial exams (GCS, pupils, motor), NIRS, EEG, transcranial Doppler.
- Aims: Detect hypoxic-ischemic injury, embolic/hemorrhagic stroke; imaging (CT/MRI) if delayed awakening or concern.
Respiratory Management
- Ventilation: Lung-protective strategy (low VT, plateau <25 cmH₂O), avoid overdistension/atelectasis.
- Watch for: Differential hypoxia (Harlequin syndrome)—upper vs lower body saturation gap.
Renal & Metabolic
- Monitor: Urine output, creatinine, lactate, acid–base.
- Actions: Avoid fluid overload; initiate CRRT when indicated (positive balance, oliguria, refractory acidosis).
Hematology & Anticoagulation
- Routine: ACT, aPTT, anti-Xa (e.g., anti-Xa 0.3–0.5), correlate with TEG/ROTEM for goal-directed hemostasis.
- Balance: Bleeding vs thrombosis; monitor oxygenator for clots.
Circuit Monitoring & Readiness
- Parameters: Pump RPM/flow trends, pre/post-oxygenator pressures (ΔP for clot burden), post-oxygenator PaO₂/PaCO₂.
- Emergency: Hand-crank, backup circuit, clamps, vasopressors/fluids/blood as needed.
Limb Perfusion
- Tools: Doppler, NIRS (leg), clinical checks (color, temperature, tenseness), distal perfusion cannulaor grafts.
Imaging & Ultrasound/Echo Roles
- X-ray/CT: Cannula position, complications.
- Ultrasound: Vessel size/patency, DPC placement.
- Echo (key): Cannula/flow guidance, LV/RV recovery, aortic valve opening, thrombus; weaning tests at reduced flow using EF, LVOT VTI, lateral mitral S′, MAP.
Microcirculation (Sublingual)
- Method: SDF/IDF clips to derive TVD, PPV/PVD; trends help judge perfusion and weaning success.
Key Takeaways
- Continuous, multimodal, integrated monitoring is critical.
- Focus on early complication detection, organ support optimization, and objective weaning assessment to improve outcomes