Optimization of the circuit configuration of a pulsatile ECLs: an in vivo experimental study.
An extracorporeal life support system (ECLS) with a conventional membrane oxygenator requires a driving force for the blood to pass through hollow fiber membranes. We hypothesized that if a gravity-flow hollow fiber membrane oxygenator is installed in the circuit, the twin blood sacs of a pulsatile ECLS (the Twin-Pulse Life Support, T-PLS) can be placed downstream of the membrane oxygenator. This would increase pump output by doubling pulse rate at a given pumpsetting rate while maintaining effective pulsatility. The purpose of this study was to determine the optimal circuit configuration for T-PLS with respect to energy and pump output. 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 of the T-PLS. In the parallel group, the twin blood sacs were placed downstream of the gravity-flow membrane oxygenator. Energy equivalent pressure (EEP), surplus hemodynamic energy (SHE) and pump output were collected at the different pump-setting rates of 30, 40, and 50 beats per minute (BPM). At a given pump-setting rate the pulse rate 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, while 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. SHE at each pump setting rate was 20,131 +/- 1408, 21,739 +/- 2470, and 15,048 +/- 2108 erg/ cm3 in the parallel group, while 33,968 +/- 3001, 38,232 +/- 3281, 37,964 +/- 2693 erg/cm3 in the serial group. Pump output was higher in the parallel circuit at 40, and 50 BPM 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). Either parallel or serial circuit configuration of T-PLS generates effective pulsatility. As for the pump out, the parallel circuit configuration provides higher flow than the serial circuit configuration by doubling the pulse rate at a given pump-setting rate.
Lim
Choon Hak
CH
Department of Anesthesiology and Pain Medicine, Korea University, Seoul, Korea
Son
Ho Sung
HS
Lee
Jung Joo
JJ
Fang
Yong Hu
YH
Moon
Ki Chul
KC
Ahn
Chi Bum
CB
Kim
Kyung Hyun
KH
Lee
Hye Won
HW
Sun
Kyung
K
D000818:Animals; D000831:Animals, Newborn; D001794:Blood Pressure; D004562:Electrocardiography; D004734:Energy Metabolism; D005069:Evaluation Studies as Topic; D005112:Extracorporeal Circulation / Q000295:instrumentation* / Q000379:methods; D006112:Gravitation; D006439:Hemodynamics; D010107:Oxygenators, Membrane; D011673:Pulsatile Flow; D011897:Random Allocation; D034421:Sus scrofa / Q000502:physiology*