An evaluation of the Rapid Infusion System.

The performance of the Rapid Infusion System was evaluated in the laboratory. Using a conventional mixture of two units of packed red cells, two units of fresh frozen plasma and 500 ml crystalloid, a single line and a driving pressure of 300 mmHg, the highest flow in our study was 970 ml.min-1 (2.8 mm catheter, no stopcock). With a 1.6 mm venous cannula the measured flow was 640 ml.min-1. Additional diluting of the standard 'blood cocktail' did not add much to the performance of the system. When primed with tap water 21 degrees C (12 degrees C respectively), the fluid at the outlet of the system reached a maximum temperature of 37.8 degrees C (37.4 degrees C) after 6 min at a flow of 400 ml.min-1. At flows higher than 1150 ml.min-1 (priming with 12 degrees C tap water: 800 ml.min-1), the system slowed down to flows of 700 to 1000 ml.min-1 in order to maintain an adequate temperature. We conclude, that the Rapid Infusion System is a valuable tool for situations where a rapid but controlled replacement with warmed blood at rates up to at least 1100 ml.min-1 is needed. The use of large bore intravenous catheters and avoiding additional resistors such as standard 3-way stopcocks is highly recommended.