• Principle functions of venous reservoir:
i) Acts as a high capacitance (low pressure) receiving
chamber for venous return; facilitates gravity drainage of venous blood
ii) Acts as a buffer for fluctuation & imbalances
between venous return & arterial flow
ii) Remove both air & microaggregates present in
venous blood
1) Hardshell reservoir
• Rigid (hard) transparent plastic canister
• Contains a defoaming layer and a filtering screen (100-200 mm)
• Capacity: 1 — 4.5 litres
• Advantages: •
easier to measure volume
•
handles venous air more effectively
•
easier to prime
•
less expensive
2) Softshell reservoir
• ‘Bag’ consists of soft PVC
• Contains a defoaming polyurethane layer (optional) and a
filtering screen (100-200 mm)
• Capacity: 200 — 3000 ml
• Advantages: •
eliminates blood-gas interface
•
reduce risks of massive air embolism because they collapse when empty