Hemodynamic evaluation of the Avalon Elite bi-caval dual lumen cannulae

In previous studies, we have evaluated the hemodynamic properties of selected oxygenators, pumps (centrifugal and roller), and single lumen cannulae. Because the dual lumen cannulae are widely used in veno-venous extracorporeal life support (ECLS) and are receiving popularity due to their advantages over the single lumen cannulae, we evaluated the flow ranges and pressure drops of three different sizes of Avalon Elite dual lumen cannulae (13Fr, 16Fr, and 19Fr) in a simulated neonatal ECLS circuit primed with human blood. The experimental ECLS circuit was composed of a RotaFlow centrifugal pump, a Capiox BabyRX05 oxygenator, 3 ft of 1/4-in venous and arterial line tubing, an Avalon Elite dual lumen cannula, and a soft reservoir as a pseudo-right atrium. All experiments were conducted at 37°C using an HCU 30 heater-cooling unit and with human blood at a hematocrit of 36%. The blood pressure in the pseudo-right atrium was continuously monitored and maintained at 4-5 mm Hg. For each cannula, pump flow rates and pressures at both the arterial and venous sides were recorded at revolutions per minute (RPMs) from 1750 to 3750 in 250 intervals. For each RPM, six data sets were recorded for a total of 162 data sets. The total volume of the system was 300 mL. The flow range for the 13Fr, 16Fr, and 19Fr cannulae were from 228 to 762 mL/min, 478 to 1254 mL/min, and 635 to 1754 mL/min, respectively. The pressure drops at the arterial side were higher than the venous side at all tested conditions except at 1750 rpm for the 19Fr cannula. The results of this study showed the flow ranges and the pressure drops of three different sized dual lumen cannulae using human blood, which is more applicable in clinical settings compared with evaluations using water.