M. Sjoquist1, D. Nelson1, D. Schaub1, W. Snell1, N. Jones1, L. Gries1 1University Of Arizona, Trauma/Surgery/Medicine, Tucson, AZ, USA
Introduction: High-flow intravenous (IV) access is critical during trauma, where high-volume resuscitation is required for the patient’s survival. A Belmont Rapid Infuser can infuse large volumes of fluid and is often used in trauma. Many different devices, cannulas, attachments, and fluids are used, but it is not well-known how these impact flow rates. This study aimed to investigate these variables using a Belmont.
Methods: A Belmont was hooked up to either 3L bag of 0.9% normal saline (NS) or blood using standard tubing. Devices tested included Cordis, Rapid Infusion Catheter (RIC), 14g, 16g, 18g, 20g, and 22g, along with needle-free valves (claves), and straight and curved pigtails. The blood product used in testing combined 2 units of whole blood, 2 units of plasma, and an additional 100mL of acid citrate dextrose. Three 1L bolus trials were conducted per data point and timed with a smartphone with the infusion rate set to 750 mL/s. Results were averaged, and flow rates were calculated. Trial times include air purges performed every 500ml by the Belmont.
Results: IVs were either pressure (300 mmHg) or flow (750mL/min) limited by the Belmont. Cordis, RIC, and 14g using NS and the RIC and Cordis with blood were flow rate limited. All other trials were pressure limited. Flow rates increased with IV size until max flow was achieved with the 14g. Flow rates in mL/min were 95 for 22g, 127 for 20g, 205 for 18g, 414 for 16g, 674 for 14g, 619 for RIC, and 664 for Cordis.
NS vs. blood showed minimal difference using the Cordis (-5%) and RIC (+3). Rates with blood slowed more with 14g (-35%), 16g(-22%), and 18g (-25%). Adding a clave was more restrictive with increasing IV size, with the 16g (-45%), 14g (-58%), RIC (-52%), and Cordis (-55%) being affected more than the 18g (-23%), 20g (-12%), and 22g (-13%). We noted an initial “break-in” period with new claves. A new clave attached to a 14g resulted in a 25 ml/min decrease (281 to 256 mL/min) compared to one previously used.
Straight pigtails restricted the flow rate to around 210 mL/min with the 14g (-68%) and 16g (-49%) until the rate became IV limited; however, the 18g rate was still slowed by 25%. Curved pigtails slowed the 14g (-24%) the most with 16g (-5%) and 18g (-5%) being minimally impacted.
Conclusion: IV size, fluid type, and attachments impact flow rates. Cordis and RIC are equivalent to a 14g with NS but 14g restricts infusion rates when used with blood, suggesting a Cordis or RIC should be used in trauma. Claves attached to a Cordis, RIC, or 14g convert the flow rate to the equivalent of 18g, but smaller IVs are less affected. Claves have a “break-in” period when initially used. Straight pigtails restrict more than curved ones.
