Indications

• Maintain visibility in operative field
• Prevent distension of cardiac chambers
• Post-heparinisation suction device
• ‘Sucker bypass’ – if extreme haemorrhage, until venous cannulation is established

Mechanism

Suction driven by roller pump. The position adjusted by surgeon and flow rate adjusted by perfusionist to keep pressure as low as needed to prevent injury to blood and prevent occlusion.

Complications

Operative field blood is highly ‘activated’ with:

• Fibrinolytic mediators,
• Inflammatory mediators (leukocuytes, endotoxins, cytokines),
• Rubbish (microparticles, fat, cellular aggregates)

Air-blood interface causes haemolysis, platelet injury/loss, hence amount of air aspirated is surrogate for injury to cells.

High negative pressure during suction contributes to haemolysis. This can be caused by occlusion, or high flow rate.

Suction of non-anti-coagulated blood at end of CPB, due to suction after giving protamine. Clots can be formed in CPB circuit which will necessitate priming a new circuit if CPB is to be re-established.

Avoiding complications

• Haemostasis to reduce bleeding and hence use of suction
• Minimise air aspiration by:
  • Low negative pressure
  • Slow suction rate, or turning suction off
  • Avoid sucking dry
  • Keep tip under blood level
• Filtration of suction blood (leukocyte depletion)
• Cell salvage instead of cardiotomy suction
• Off-pump surgery