A Study of Optimal Model for the Circuit Configuration of Korean Pulsatile Extracorporeal Life Support System (T-PLS)

Lim, Choon Hak; Sun, Kyung; Son, Ho Sung; Lee, Jung Joo; Hwang, Znuke; Lee, Hye Won; Kim, Kwang Taik

Abstract

BACKGROUND: We have hypothesized that, if a low resistant gravity-flow membrane oxygenator is used, then the twin blood sacs of TPLS can be located at downstream of the membrane oxyenator, which may double the pulse rate at a given pump rate and increase the pump output. The purpose of this study was to determine the optimal configuration for the ECLS circuits by using the concept of pulse energy and pump output. MATERIAL AND METHOD: Animals were randomly assigned to 2 groups in a total cardiopulmonary bypass model. In the serial group, a conventional membrane oxygenator was located between the twin blood sacs. In the parallel group, the twin blood sacs were placed downstream of the gravity-flow membrane oxygenator. Energy equivalent pressure (EEP) and pump output were collected at pump-setting rates of 30, 40, and 50 BPM. RESULT: At the given pump-setting rate, the pulse rate was doubled in the parallel group. Percent changes of mean arterial pressure to EEP were 13.0+/-1.7, 12.0+/-1.9 and 7.6+/-0.9% in the parallel group, and 22.5+/-2.4, 23.2+/-1.9, and 21.8+/-1.4% in the serial group at 30, 40, and 50 BPM of pump-setting rates. Pump output was higher in the parallel circuit at 40 and 50 BPM of pump-setting rates (3.1+/-0.2, 3.7+/-0.2 L/min vs. 2.2+/-0.1 and 2.5+/-0.1 L/min, respectively, p=0.01).
CONCLUSION
Either parallel or serial circuit configuration of the ECLS generates effective pulsatility. As for the pump out, the parallel circuit configuration provides higher flow than the serial circuit configuration.