ECMO Circuit Components: cannulas, tubing, pump, membrane oxygenator, pressure/flow monitors, and other additional components (Dr. Faten Farid)
ECMO Overview
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Two ECMO types:
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VV ECMO: For respiratory support
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VA ECMO: For cardiac support
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Circuit components: Include pump (centrifugal/roller), oxygenator, cannulas, heat exchanger
Cannulas & Technical Details
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Biocompatible, wire-reinforced cannulas collapse for insertion, expand in position
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Proper cannula sizing and placement (e.g., IVC for drainage) essential for adequate flow
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Monitoring via ECMO consoles includes RPM, flow rate, and backup hand crank system
Oxygenator Function & Circuit Safety
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Oxygenators:
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Polypropylene for short-term
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Polyimide for long-term
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Heat exchanger regulates blood temperature
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Vigilance required to prevent thrombus, air embolism, and disconnection
Circuit Monitoring Essentials
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Low flow may suggest cannula size/clot issues
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Non-invasive monitors detect air bubbles and trigger alarms
Monitor flow, efficacy, harm:
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Track pump speed, circuit pressures, gas flow
Pressure Monitoring
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Pre-pump, post-pump pre-oxygenator, post-oxygenator
Key pressures:
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Rising delta pressure = resistance or obstruction
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Emphasized trend monitoring over isolated readings
Oxygenator Monitoring
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Check pre- and post-oxygenator PO₂ (>300–350 mmHg ideally)
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Watch for recirculation or contamination that skews readings
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Decline in efficacy suggests need for replacement
Safety & Complication Awareness
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Monitor for bleeding, thrombosis, hemolysis
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Use of alarms, bubble detectors, and battery backups is critical for safe operation