iThoughts

The roller pump is still the most commonly used but can cause haemolysis and release of vasoactive substances, as well as particulate micro emboli from the tubing. The centrifugal pump avoids this.
Reduction in RBC, platelet and protein damage.
Arterial line needs to be clamped when the pump is not running.

Contact between blood and he material in the CPB circuit can activate complement, kinin, fibrinolytic, and coagulation cascades
Also activates neutrophils which can go on to cause SIRS, MOF, bleeding diathesis. More biocompatible coatings are used now.
Heparin coating of the circuit also makes it more biocompatible. Phosphorylcholine is also used as it mimics the natural cell membrane

Membrane oxygenator most commonly used as it permits gas exchange without the blood trauma of direct-contact oxygenators.
Gas transfer is via transmembrane diffusion or via micropores (0.1 μm) produced by stretching propylene
Membrane can either be flat sheets or hollow fibres. Blood flows over the fibres while gas passes through them. Eddies ensure blood continually brings more red cells to the gas exchange surface.
O2/air blender is used to regulate pO₂, and the FGF rate determines the pCO₂
Can accumulate a proteinaceous coating
Heparin coated, to simulate endothelium

Used to measure pH, pO₂, K+,Hct, SpO₂, Hb, T. It uses spectrophotometric optical fluoroescence.

Has been used to reduce haemodilution during CPB and reduce volume overload and EVLW