PERIPHERAL INTRAVENOUS CATHETER: COMPARISON OF FEP AND PUR CANNULA MATERIALS
I. What is a Peripheral Intravenous Catheter?
A Peripheral Intravenous Catheter (PIVC) is an essential medical device widely used in patient care and treatment. It consists of a needle combined with a flexible cannula, which allows healthcare professionals to deliver medications, infusion fluids, blood products, and nutrients directly into a patient’s bloodstream. The catheter can be maintained in the vein for several days, reducing the need for repeated needle punctures and facilitating blood sampling when required.
II. Classification
Peripheral intravenous catheters are manufactured in various needle sizes, typically ranging from 1.4 to 2.4 mm in diameter, depending on clinical application. The size of a catheter is determined by the Gauge (G) system: the smaller the gauge number, the larger the needle diameter. For ease of use and quick identification, catheters are also color-coded according to their gauge size.
Table 1: Classification and Technical Specifications of Peripheral Intravenous Catheters
| Size | Color | Diameter (mm) | Length (mm) | Flow rate (ml/min) |
| 14G | Orange | 2.0 | 45 | 250 |
| 16G | Grey | 1.7 | 45 | 200 |
| White | 1.5 | 45 | 125 | |
| 18G | Green | 1.3 | 45 | 95 |
| 20G | Pink | 1.1 | 32 | 62 |
| 22G | Blue | 0.9 | 25 | 33 |
| 24G | Yellow | 0.7 | 19 | 20 |
| 26G | Purple | 0.6 | 19 | 15 |
Figure 1: Catheter sizes are classified according to different color codes.
III. Cannula Materials
Currently, two main materials are commonly used in the production of peripheral intravenous catheter cannulas: Fluorinated Ethylene Propylene (FEP) and Polyurethane (PUR). Each material possesses distinct mechanical properties, making it suitable for different clinical indications.
Table 2: Comparison of Advantages and Disadvantages of the Two Cannula Materials
| Materials | FEP | PUR |
| Advantages | – High rigidity and mechanical strength → reduces the risk of catheter breakage or kinking. – Provides a “firm grip” for healthcare professionals during insertion and infusion. | – High flexibility and adaptability to the anatomical variations of veins. – Minimizes the risk of vascular injury. – Reduces pain during insertion and ensures greater patient comfort throughout catheter placement. |
| Limitations | Due to rigidity: – Higher risk of damaging the vessel wall. – Patients may experience pain or discomfort when the catheter is indwelling for prolonged periods, with increased risk of phlebitis. | Due to softness: – May feel less stable during infusion, giving the impression of catheter “slackness.”- Higher likelihood of kinking or lumen collapse when patients move excessively. |
| Best suited for | Cases requiring high-pressure infusions or long-term catheter placement. | Patients with small or fragile veins, or those who are sensitive, such as children and the elderly. |
Figure 2: Vinacath peripheral intravenous catheter with FEP cannula manufactured by USM Healthcare
Figure 3: Favocath peripheral intravenous catheter with PUR cannula manufactured by USM Healthcare
IV. Conclusion
Both FEP and PUR are safe, medical-grade materials widely applied in the manufacturing of peripheral intravenous catheter cannulas. The choice of material should be guided by the condition of the patient’s veins, the type of infusion or medication required, and individual patient characteristics.
- FEP: Recommended for cases requiring strong mechanical durability, structural stability, or high-pressure infusions.
- PUR: Recommended for patients with small or difficult veins, or when patient comfort and reduced risk of phlebitis are priorities.
This distinction enables healthcare professionals to make informed choices, thereby optimizing treatment outcomes and enhancing the overall patient care experience.