Investigation of the pathophysiology of cardiopulmonary bypass using rodent extracorporeal life support model

Abstract

BackgroundExtracorporeal life support (ECLS) systems are life-saving devices used for treating patients with severe cardiopulmonary failure. In this study, we implemented a rat model of ECLS without the administration of inotropes or vasopressors.MethodsThe rats underwent 5 min of untreated asphyxial cardiac arrest and were resuscitated by ECLS for 30 min. The right external jugular vein and right femoral artery were separately cannulated to the ECLS outflow and inflow, respectively. Thereafter, ECLS was terminated, wounds were closed, and mechanical ventilation was provided for another 90 min. Subsequently, blood gas and hemodynamic analyses were performed. The plasma levels of C-reactive protein (CRP), interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha (TNF-α) were measured 120 min after reperfusion.ResultsThe metabolic rate of lactate in the group of asphyxial cardiac arrest rescued by ECLS was slow; therefore, the pH at 120 min after reperfusion was significantly lower in this group than that in the group of normal rats treated with ECLS. The hemodynamic data showed no between-group differences. The plasma levels of CRP, IL-6, IL-10, and TNF-α increased after ECLS treatment.ConclusionsWe successfully established a rodent ECLS model, which might be a useful approach for studying the pathophysiology induced by ECLS under clinical conditions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12872-017-0558-6) contains supplementary material, which is available to authorized users.

Cardiac and Vascular Surgery–Associated Acute Kidney Injury: The 20th International Consensus Conference of the ADQI (Acute Disease Quality Initiative) Group

“…Finally, the effect of the cardiopulmonary bypass (CPB) circuit itself in the case of cardiac surgery is notable. Although animal models of CPB and cardiac surgery–associated AKI (CS‐AKI) exist, they have not been widely applied to the study of AKI. Furthermore, although clinical studies have been conducted for >40 years, numerous knowledge gaps remain.…”

Extracorporeal Life Support Enhances the Forward Pressure Wave to Cause a Mismatch between Cardiac Oxygen Demand and Supply

“…We had previously observed high levels of inflammatory cytokines in rats at 120 min after reperfusion 22 , demonstrating persistent inflammatory insults, even after the rats had been weaned from ECLS. These inflammatory responses can be induced by the adrenergic pro-inflammatory pathway 23 , which might cause accelerated heartbeat after ECLS 22 . However, ECLS exerted no significant alterations in aortic pressure profiles such as P s , P d , P m , P ms , and P md except PP and P ms / P md .…”

“…This study has some limitations. Because a rat’s blood volume is approximately 7% of that rat’s body weight 32 , the priming volume of our extracorporeal membrane oxygenator (ECMO) circuit was about 19–20 ml, which accounted for 61% of blood volume in the studied rats 22 . The priming volume used in this study was the minimum volume that we could attain in our model.…”

“…The procedure for the implementation of ECMO in rats was conducted as described previously 22 . In brief, rats were anesthetized with 5% isoflurane/100% oxygen in an induction chamber (Serial number 4468, NorVap, Skipton, UK; Panion & BF Biotech Inc., Nangang Dist., Taipei, Taiwan), and then mechanically ventilated (tidal volume 7 mL kg −1 , rate 40 breaths min −1 , positive end-expiratory pressure 2 cmH 2 O; Model 131, New England Medical Instruments, Medway, MA, USA) by orotracheal intubation with 1.75%–2% isoflurane/0.7–0.8 L min −1 oxygen for maintenance.…”

“…In brief, rats were anesthetized with 5% isoflurane/100% oxygen in an induction chamber (Serial number 4468, NorVap, Skipton, UK; Panion & BF Biotech Inc., Nangang Dist., Taipei, Taiwan), and then mechanically ventilated (tidal volume 7 mL kg −1 , rate 40 breaths min −1 , positive end-expiratory pressure 2 cmH 2 O; Model 131, New England Medical Instruments, Medway, MA, USA) by orotracheal intubation with 1.75%–2% isoflurane/0.7–0.8 L min −1 oxygen for maintenance. The rats were placed on a circulating warm water blanket (B401H, Firstek Scientific Co. Ltd., Xinzhuang Dist, New Taipei City, Taiwan; TP22G, Gaymar Industries, Inc., Orchard Park, NY, 14127 USA) with a heating lamp above for maintaining body temperature 22 .…”