Flow Management Strategies For VA-ECMO In Patients With Cardiogenic Shock

Aims: Veno-arterial extracorporeal membrane oxygenation(VA-ECMO)is currently one of the most used mechanical auxiliary devices for patients with refractory cardiogenic shock(CS).At present,how to set the ‘optimal’ flow is still uncertain,the influence of inappropriate support flow can not be ignored.This study aims to the impact of "high flow" support on the prognosis of patients.Methods: Retrospective analysis was made on the basic data and treatment of 93 patients with CS who received VA-ECMO support in the Jinhua Central Hospital from February 2015 to November 2022.Based on the median flow during the first 48 h of the VA‐ECMO,patients were classified into "high flow" or "low flow" groups according to the flow rate ≥3.6L/min or <3.6L/min,recording the incidence rate of hypertension and diabetes,APACHE-II score,statistics of the primary cause of disease,variation trend of VA-ECMO flow within 7 days,recording the blood lactic acid level before and after VA-ECMO boarding,as well as the creatinine and urea nitrogen values at 2h,24 h and 48 h after running,observing the incidence of acute kidney injury(AKI),continuous renal replacement therapy(CRRT),mechanical ventilation days and stay in intensive care unit(ICU),and the success rate and final prognosis of patients.Multivariate COX regression was used to analysis the risk factors of VA-ECMO.Results: A total of 93 patients with an average age of 47 years were studied,which including 47(50.5%)in the "high flow" group and 46(49.5%)in the "low flow" group.Acute myocardial infarction(42 cases)and fulminant myocarditis(22 cases)are the two most common causes of CS.The APACHE-II scores and lactate level of patients in the "high flow" group were higher than those in the "low flow" group,and the incidence of AKI and the time to receive CRRT were longer(P<0.05).The days of mechanical ventilation in the "low flow" group were less than "high flow" group(P<0.05).There was no statistical difference between the two groups of patients in terms of VA-ECMO operation days,hospital stay,and withdrawal success rate.Multivariate COX regression analysis showed that the initial flow of VA-ECMO,lactic acid before boarding and age,were risk factors for death.Conclusions: In patients treated with VA-ECMO for CS,compared with the "low flow" group,the probability of AKI is higher,the time of CRRT and mechanical ventilation is longer.High flow support in the early stage is one of the risk factors for death.The support flow of VAECMO,lactic acid value before computer operation and age can predict the death of patients.