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Technical
IVT
venous air lock
Condition where air bubbles trapped in venous cannulae impede venous return during cardiopulmonary bypass.
Full Definition
A potentially dangerous situation where air accumulates in the venous drainage system, creating a barrier that prevents adequate venous return to the bypass pump. This can occur due to inadequate venous cannula positioning, kinked tubing, or entrainment of air through surgical sites. Venous air lock can rapidly lead to pump cavitation, inadequate systemic perfusion, and hemodynamic instability, requiring immediate recognition and correction by repositioning cannulae or increasing venous reservoir level.
Usage
Usage note: Emergency situation requiring immediate intervention.
In Context
- "Venous air lock was suspected when pump flow suddenly decreased despite adequate systemic pressure." — Perfusion emergency note
- "The perfusionist cleared the venous air lock by briefly increasing reservoir level and adjusting cannula position." — Incident report
Also known as
venous line air lock
drainage obstruction
Contrasted with
optimal venous return
Don't confuse with
pump cavitation
cannula malposition