Life Support Systems in Terms of Energy

ABSTRACT

BACKGROUND: The pro's and con's of pulsatile versus nonpulsatile perfusion during acute and chronic mechanical circulatory support is a longstanding controversial issue, some investigators have suggested that the simplest explanation for this controversy is a failure to quantitate adequately the pulsatile components of flow in studies. The aim of this study was to examine the pulsatility generated by centrifugal pump (CP) and a pulsatile extracorporeal life support (twin pulse life support, T-PLS) in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE). METHODS: In each of the 5 cardiac arrested pigs, the outflow cannula of the CP or T-PLS was inserted into the ascending aorta, and the inflow cannula of the CP or T-PLS was placed in the right atrium. Extracorporeal circulation was maintained for 30 minutes using a pump flow of 75 ml/kg/min by CP or T-PLS, respectively. Pressure and flow were measured in the right internal carotid artery. RESULTS: No statistical difference was observed between CP and T-PLS in terms of mean carotid artery pressure. However, pulse pressure, the percent change from mean arterial pressure to EEP, and SHE in T-PLS were higher than CP (pulse pressure 36.1 +/- 3.6 mmHg vs 9.1 +/- 1.3 mmHg, P < 0.05, the percent change from mean arterial pressure to EEP 19.8 +/- 6.2% vs 0.2 +/- 0.3%, P < 0.05). CONCLUSIONS: In a cardiac arrested animal model, CP revealed nonpulsatility and pulsatility generated by T-PLS was effective in terms of EEP and SHE.