IV Catheter Quick Reference

Peripheral IV catheter reference for EMS providers. Gauge sizes, color codes, flow rates, catheter selection guidelines, complications, and prehospital site selection.

IV Catheter Quick Reference

Peripheral IV Catheter Gauge Chart

Gauge	Color	OD	Length	Flow Rate
14G	Orange	2.1 mm	4.5 cm (1.75")	~330 mL/min
16G	Gray	1.7 mm	4.5 cm (1.75")	~210 mL/min
18G	Green	1.3 mm	3.0 cm (1.25")	~105 mL/min
20G	Pink	1.1 mm	2.5 cm (1.0")	~60 mL/min
22G	Blue	0.9 mm	2.5 cm (1.0")	~36 mL/min
24G	Yellow	0.7 mm	1.9 cm (0.75")	~22 mL/min
26G	Violet	0.6 mm	1.9 cm (0.75")	~13 mL/min

Clinical Uses by Gauge

14G (Orange)

Major trauma resuscitation | Rapid volume replacement | Surgical settings

16G (Gray)

Trauma | Blood transfusion | Rapid fluid administration | Surgery

18G (Green)

Blood products | General medical patients | Moderate fluid resuscitation

20G (Pink)

Most IV infusions | Maintenance fluids | Medication administration

22G (Blue)

Pediatric patients | Elderly/fragile veins | Medication infusions

24G (Yellow)

Neonatal | Pediatric | Very small or fragile veins

26G (Violet)

Neonatal | Very fragile veins | Slow medication infusions only

Sources: Pedagogy Education. "Peripheral IV Catheter Gauge Chart and Uses." 2023.; NYSORA (New York School of Regional Anesthesia). "Peripheral Venous Catheter Selection Guide." 2022.; INS (Infusion Nurses Society). "Standards of Practice for Infusion Therapy." J Infusion Nursing. 2021;44(1S).; NAEMSP. "Prehospital Vascular Access Position Statement." 2020.; Emergency Nurses Association. "Clinical Practice Guideline: Difficult Intravenous Access." 2015.

Quick Tips

Gauge vs. Size:

Higher gauge number = smaller catheter. A 14G is the largest common peripheral catheter; 26G is the smallest.

Two IV Rule:

Trauma patients should have two large-bore (16G or larger) IVs established. Use antecubital veins for fastest access.

Blood Products:

Minimum 18G for blood transfusions. Smaller gauges cause hemolysis of red blood cells.

Gauge Color Memory Aid

14G Orange — "Orange for Oh-no trauma"

16G Gray — "Gray for Grave situations"

18G Green — "Green for Go-to catheter"

20G Pink — "Pink for Pretty standard"

22G Blue — "Blue for Baby-friendly"

24G Yellow — "Yellow for Young/tiny"

Clinical Pearls

Select the smallest gauge that meets your clinical need. Smaller catheters are less painful, cause less vein trauma, and allow better blood flow around the catheter.

Consider IO access early. If IV access fails after two attempts or 90 seconds in critical patients, switch to intraosseous (IO) access per protocol.

Flow rate depends on more than gauge. Catheter length, fluid viscosity, IV height, and tubing size all affect actual flow rates. Published rates are gravity-fed approximations.

Secure your IV well. Prehospital movement increases catheter dislodgement risk. Use commercial securement devices and loop tubing to create a stress relief.

Disclaimer

This reference is for educational purposes and clinical decision support only. It is not a substitute for local protocols, medical direction, or manufacturer specifications. Catheter specifications and flow rates may vary by manufacturer. Always follow your agency's protocols and consult medical control as appropriate.