Emergency Medical Minute

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.