BACKGROUND

The objective of this study was to evaluate the pump performance of the novel diagonal Medos Deltastream DP3 diagonal pump (MEDOS Medizintechnik AG, , Stolberg, Germany) under nonpulsatile to pulsatile mode with varying differential speed values in a simulated pediatric extracorporeal life support system.

METHODS

The experimental circuit consisted of a Medos Deltastream DP3 pump head and console, a Medos Hilite 2400 LT hollow fiber membrane oxygenator (MEDOS Medizintechnik AG), a 14F Medtronic DLP arterial cannula (Medtronic Inc, Minnesota), and a 20F Terumo TenderFlow Pediatric venous return cannula (Terumo Corporation, Michigan). Trials were conducted at flow rates ranging from 500 mL/min to 2,000 mL/min (500 mL/min increments) and pulsatile differential speed values ranging from 500 rpm to 2,500 rpm (500 rpm increments) using human blood (hematocrit 35%). The postcannula pressure was maintained constantly at 60 mm Hg. Real-time pressure and flow data were recorded using a custom-made data acquisition system and Labview software.

RESULTS

Under all experimental conditions, pulsatile flow (P) generated significantly greater energy equivalent pressure (EEP), surplus hemodynamic energy (SHE), and total hemodynamic energy (THE) than those of nonpulsatile flow (NP). Under NP, SHE was zero. Higher differential speed values generated greater EEP, SHE, and THE values. There was little variation in the oxygenator pressure drop and the cannula pressure drop in P, compared to NP.

CONCLUSIONS

The novel Medos Deltastream DP3 diagonal pump is able to generate physiological quality of P, without backflow. With increased differential rpm, the pump generated greater EEP, SHE, and THE. Physiological quality of pulsatility may be associated with better microcirculation because of greater EEP, SHE, and THE.