An innovative ovine model of severe cardiopulmonary failure supported by veno-arterial extracorporeal membrane oxygenation

Refractory cardiogenic shock (CS) often requires veno-arterial extracorporeal membrane oxygenation (VA-ECMO) to sustain end-organ perfusion. Current animal models result in heterogenous cardiac injury and frequent episodes of refractory ventricular fibrillation. Thus, we aimed to develop an innovative, clinically relevant, and titratable model of severe cardiopulmonary failure. Six sheep (60 ± 6 kg) were anaesthetized and mechanically ventilated. VA-ECMO was commenced and CS was induced through intramyocardial injections of ethanol. Then, hypoxemic/hypercapnic pulmonary failure was achieved, through substantial decrease in ventilatory support. Echocardiography was used to compute left ventricular fractional area change (LVFAC) and cardiac Troponin I (cTnI) was quantified. After 5 h, the animals were euthanised and the heart was retrieved for histological evaluations. Ethanol (58 ± 23 mL) successfully induced CS in all animals. cTnI levels increased near 5000-fold. CS was confirmed by a drop in systolic blood pressure to 67 ± 14 mmHg, while lactate increased to 4.7 ± 0.9 mmol/L and LVFAC decreased to 16 ± 7%. Myocardial samples corroborated extensive cellular necrosis and inflammatory infiltrates. In conclusion, we present an innovative ovine model of severe cardiopulmonary failure in animals on VA-ECMO. This model could be essential to further characterize CS and develop future treatments.

Effect of Acute Limb Ischemia on the Mortality of Patients with Extracorporeal Membrane Oxygenation Established by Femoral Vein-Arterial Catheterization and Analysis of Related Risk Factors

Extracorporeal membrane oxygenation (ECMO) is a common treatment for cardiopulmonary failure. Although it can effectively reduce the mortality of patients with cardiopulmonary failure, it still has a high mortality rate, such as acute limb ischemia (ALI), stroke, liver and kidney failure, and other related complications and related causes of death. This study aims to explore the impact of ALI on the mortality of VA-ECMO patients in hospital and 6 months after discharge and analyze the occurrence of ALI and related factors that affect the mortality of VA-ECMO in hospital and 6 months after discharge. The results showed that the smoking history was an independent risk factor for ALI, and age, diabetes, cardiac arrest, first time of ECMO, and hyperbilirubinemia were associated risk factors for in-hospital mortality. Cardiac arrest and ALI were associated risk factors for mortality at 6 months after discharge. Although ALI is not significantly associated with VA-ECMO in-hospital mortality, it is a risk factor for mortality at 6 months after discharge, and medical personnel should therefore strive to reduce and avoid ALI.

Postcardiotomy Extracorporeal Membrane Oxygenation in Neonates

Background Extracorporeal membrane oxygenation (ECMO) provides circulatory support in children with congenital heart disease, particularly in the setting of cardiopulmonary failure and inability to wean from cardiopulmonary bypass. This study summarized the clinical application of ECMO in the treatment of heart failure after cardiac surgery in neonates. Materials and Methods Clinical data of 23 neonates who received ECMO support in our center from January 2017 to June 2019 were retrospectively analyzed. Results Twenty-three neonates, aged from 0 to 25 days and weight between 2,300 and 4,500 g, with heart failure postcardiotomy were supported with ECMO. The successful weaning rate was 78.26% and discharge rate was 52.17%. Bleeding and residual malformation were the most common complications. The univariate analysis showed that nonsurvivors were related to the factors such as higher lactate value of ECMO 12 and 24 hours (p = 0.008 and 0.001, respectively), longer time to lactate normalization (p = 0.001), lactate > 10 mmol/L before ECMO (p = 0.01), lower weight (p = 0.01), longer ECMO duration (p = 0.005), lower platelet count (p = 0.001), more surgical site bleeding (p = 0.001), and surgical residual malformation (p = 0.04). Further logistic regression analysis revealed that higher lactate value of ECMO 24 hours (p = 0.003), longer ECMO duration (p = 0.015), and surgical site bleeding (p = 0.025) were independent risk factors. Conclusion ECMO was an effective technology to support the neonates with cardiopulmonary failure after open heart surgery. Control the lactate acidosis and surgical site bleeding event may be helpful for patients' recovery.

An innovative ovine model of severe cardiopulmonary failure supported by veno-arterial extracorporeal membrane oxygenation

Background Refractory cardiogenic shock (CS), frequently complicated by pulmonary failure, often requires veno-arterial extracorporeal membrane oxygenation (VA-ECMO) to sustain end-organ perfusion. Currently available animal models, such as the coronary ligation model, result in highly variable injury profiles and unacceptably high levels of subsequent ventricular fibrillation, cardiac arrest, and death. As the use of ECMO increases, there is a growing need for a clinically relevant, robust, and titratable model of severe cardiopulmonary failure supported by VA-ECMO. Methods Six sheep (60 ± 6 kg) were anaesthetized, intubated and mechanically ventilated. VA-ECMO was initially carried out at a flow rate of 1 L/min. CS was induced through 1-mL left ventricle myocardial injections of 96% ethanol and confirmed when systolic blood pressure (SBP) was < 90 mmHg and lactate > 4 mmol/L. Then, pulmonary failure was confirmed when PaO2 was < 60 mmHg through substantial decrease in the ventilatory support. Thereafter, VA-ECMO support was increased to obtain a mean arterial pressure of 65 mmHg. Echocardiography and cardiac Troponin I (cTnI) analysis were performed at baseline, upon CS confirmation, establishment of pulmonary failure and hourly thereafter. After 5h, the animals were euthanised and the heart collected for histological and macroscopic assessment. Results Ethanol (58 ± 23 mL) rapidly induced CS in all animals. cTnI levels increased near 5000-fold. SBP decreased from 97 ± 18 mmHg at baseline to 67 ± 14 mmHg upon CS, and lactate from 1.4 ± 0.8 to 4.7 ± 0.9 mmol/L, respectively. Echocardiography studies demonstrated a decrease in the left ventricular fractional area change from 34 ± 9% upon baseline to 16 ± 7% after CS. Analysis of myocardial tissue samples corroborated extensive cellular necrosis and inflammatory infiltrates. Conclusions We present a novel titratable model of severe cardiopulmonary failure in animal on VA-ECMO, through intramyocardial ethanol injections and reduction in ventilatory support. This model could be essential to further characterize left-sided heart failure and develop future treatments.