Contributor: Travis Barlock, MD

Educational Pearls:

• Gauge and length of catheter are determinants of flow rate 
  • Smaller gauges produce higher flow rate
  • Longer catheters reduce flow rate 
•  Common IV gauges produce predictable rates of flow: 
  • 20 gauge = 60 cc/min
  • 18 gauge = 105 cc/min
  • 16 gauge = 220 cc/min 
• Central lines typically have two 18 gauge and one 16 gauge lumen, both with long catheters, producing the following slower flow rates: 
  • 18 gauge = 26 cc /min 
  • 16 gauge = 55 cc/min
• Sheath Introducers, such as Cordis brand catheters, are wider and shorter than classic central lines.
  • Flow rates are 150 cc/min, or 130 cc/min with pressure bag 
  • Maximal flow allows for one unit of blood to be delivered over one minute 
• It is important to consider length and gauge of catheter when patients require fluids

References

Greene N, Bhananker S, Ramaiah R. Vascular access, fluid resuscitation, and blood transfusion in pediatric trauma. International Journal of Critical Illness and Injury Science. 2012;2(3):135. doi:10.4103/2229-5151.100890 

Khoyratty SI, Gajendragadkar PR, Polisetty K, Ward S, Skinner T, Gajendragadkar PR. Flow rates through intravenous access devices: an in vitro study. J Clin Anesth. 2016;31:101-105. doi:10.1016/j.jclinane.2016.01.048

Summarized by Kirsten Hughes, MS4 | Edited by John Spartz, MD, & Erik Verzemnieks, MD