Table 14. Causes of decreased venous and arterial flows.

Causes of decreased venous return

(I) Position or size of venous cannula

(II) Air lock of venous cannula

(III) Lifting of heart or kinking of venous line

(IV) Misplaced tourniquet

(V) Hypovolemia- bleeding into field or different body compartment

(VI) Hyperdynamic heart- can suck blood and compete with venous cannula

Causes of decreased arterial flow

(I) Size of arterial cannula

(II) Kinking of arterial line

(III) Manipulation of aorta especially when it is small e.g. in TAPVR

TAPVR, total anomalous pulmonary venous connection.