Optimal ECLS Support in Mixed Cardiogenic and Septic Shock: An ELSO Registry Analysis
Abstract
Background
Mixed cardiogenic and septic shock has been shown to have a higher mortality than cardiogenic shock alone and presents a unique hemodynamic phenotype.
Objectives
This study aimed to evaluate whether higher circulatory support with veno-arterial extracorporeal life support (VA-ECLS) was associated with increased survival to discharge in patients with mixed shock.
Methods
We queried the Extracorporeal Life Support Organization database to identify adult (age >18 years) patients in mixed (cardiogenic and septic) shock requiring VA-ECLS between 2017 and 2022. Patients were categorized into lower (<2.2 L/min/m2 flow) or higher (≥2.2 L/min/m2 flow) circulatory support on VA-ECLS at 24 hours post-ECLS initiation.
Results
A total of 452 patients supported with VA-ECLS with mixed shock were identified. Overall mortality was 63% (n = 285). Older age (adjusted OR [aOR]: 1.02; 95% CI: 1.01-1.04; P < 0.001), pre-extracorporeal membrane oxygenation cardiac arrest (aOR: 1.71; 95% CI: 1.11-2.65; P = 0.016), and baseline Charlson Comorbidity Index (aOR: 1.13; 95% CI: 1.01-1.28; P = 0.043) were associated with increased mortality. Patients receiving higher VA-ECLS support at 24 hours were numerically more likely to survive to discharge (42.6% vs 33.8%, P = 0.063). When evaluated as a continuous variable, higher VA-ECLS flow at 24 hours was associated with an aOR of 1.31 (95% CI: 0.87-1.97; P = 0.19) for survival to discharge.
Conclusions
Patients with mixed shock requiring VA-ECLS have a high mortality. Patients with mixed shock receiving higher support at 24 hours had a trend toward increased survival to discharge compared to those with lower support. These results are hypothesis-generating, and further studies are needed.
Utilization of veno-arterial extracorporeal life support (VA-ECLS) in the treatment of refractory cardiogenic shock (CS) has increased substantially.1,2 The versatility of the VA-ECLS platform and its ability to provide comprehensive circulatory and pulmonary support has in part driven this growth.3 Optimization of VA-ECLS care in CS patients has been investigated frequently, but there remains scarce literature on the role of VA-ECLS in the management of mixed cardiogenic and septic shock.3-7 Patients in CS may develop concomitant septic shock, and conversely severe myocardial dysfunction in the setting of septic shock may also lead to CS.8-10 Recent studies have shown that mixed cardiogenic and septic shock is a growing problem in contemporary cardiovascular intensive care units and now accounts for 15% to 20% of patients presenting in shock. This cohort has also been shown to have higher mortality than patients with CS alone and often presents challenging therapeutic dilemmas.11,12
Effective oxygen delivery to the end organs is diminished in septic shock due to profound vasodilation and inefficient oxygen extraction. Increased cardiac output allows for improved oxygen delivery, but this compensation is generally blunted when CS is also present.13 It is reasonable to hypothesize that patients with mixed cardiogenic and septic shock who require circulatory support with VA-ECLS may benefit from higher flows. However, evidence supporting this principle is sparse and mostly limited to small series or pediatric patients with septic shock without cardiac dysfunction.14 We queried the Extracorporeal Life Support Organization (ELSO) database to investigate if higher circulatory support (≥2.2 L/m2) on VA-ECLS was associated with increased survival to discharge in patients with mixed shock.