Tubing Selection for Arterial and Venous Perfusion

Materials Used in Medical Tubing

• Silicone is commonly used to make shower curtains and flexible tubes.
• Silicone rubber has a molecular structure of Si-O-Si (silicon-oxygen-silicon).

Hemolysis and Tubing

• Tubing made from silicone produces less hemolysis than PVC when occluded.
• Coating with a non-thrombogenic material can reduce the inflammatory response to foreign material in tubing.

Types of Tubing

• Tubing made from a non-heparin-based biopassive polymer is an example of a biopassive tubing.
• Larger bore tubing is advantageous as it reduces pressure drop and increases flow rate.

Selection of Tubing Size

• Inner diameter and flow rate are important factors to consider when selecting the appropriate tubing size.

Material Properties

• PVC tubing requires the addition of plasticizers to make it flexible.
• Over 30,000 substances have been tested for use as a polymer plasticizer.
• Phthalates are a family of polymer plasticizers used for flexibility in plastics.
• PVC has polar bonds.

Surface Modifications

• Surface modifications in tubing used in the extracorporeal circuit are done to reduce thrombogenicity.

Manufacturing and Sterilization

• Pultrusion is a method used for the manufacture of plastic tubing that involves pulling reinforced fibers through a die.
• Medical tubing has a pressure rating of up to 1000 psi and a maximum vacuum rating of up to 29 inHg.
• Sterilization is essential for medical tubing, and the most common method is Ethylene Oxide Sterilization.
• The four essential parameters for Ethylene Oxide Sterilization are temperature, humidity, gas concentration, and time.
• The basic cycle of Ethylene Oxide Sterilization includes preconditioning, sterilization, and aeration.
• Mechanical aeration is used to remove ethylene oxide residues from the tubing.
• Ethylene Oxide Sterilization is best suited for heat-sensitive materials.

Other Facts

• Polycarbonate connectors are made of polycarbonate material.
• The process of heating the tubing and placing it on the specified connection site is called heat forming.
• Silicone tubing has worse form recovery (compression set) after being under load.
• Minimum bend radius is important for medical tubing used in the extracorporeal circuit to prevent kinking.
• Flexing a tube too far can cause kinking or cracking.

This quiz tests your knowledge on selecting appropriate tubing sizes for arterial and venous perfusion, as well as cardioplegia administration and blood scavenging. Understand how factors like body surface area and cardiac index can guide tubing selection.