Flow characteristics of admixed erythrocytes through medex tubing with a pall filter

Resuscitation with fluid and blood components is the mainstay of therapy for hypovolemic patients. This study evaluated the flow rate and resultant temperature of 6 degrees C erythrocytes admixed with warmed saline passing through a new commercial large bore tubing. The tubing is 183 cm long and is 0.57 cm in diameter. The effect on the outflow fluid temperature when catheters of various sizes were added to the system distally was also assessed. The admixed solution temperature averaged 36.2 degrees C and the outflow temperature of the mixture from the distal tubing averaged 34.9 degrees C. There was an average drop in temperature over the length of the tube of 1.5 degrees C. The filter in the Medex Hi-Flow Trauma Quad system collapsed, severely restricting fluid flow, after only four units. The problem of filter clogging was overcome by the in-line addition of a Pall filter. Addition of this in-line filter had a negligible effect on the flow rate. The flow rate with the Pall filter in-line averaged 1,150 mL/min. As the catheters that were added distally to the system diminished in size, there was a predictable decrease in the admixed fluid flow rate. A warmed saline-erythrocyte solution may be very rapidly infused through commercial large-bore tubing modified with an in-line filter. The size of the catheters used determines the ultimate flow rate.