Acid-Base Status During Venoarterial Extracorporeal Membrane Oxygenator Support in Patients With Cardiogenic Shock

Area of Science:

• Cardiology
• Critical Care Medicine
• Biochemistry

Background:

• Prognostic significance of acid-base balance in cardiogenic shock patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO) is unclear.
• Study investigated metabolic and respiratory disturbances in VA-ECMO patients with refractory cardiogenic shock using the ELSO Registry.

Purpose of the Study:

• To analyze acid-base disturbances at 24 hours post-VA-ECMO initiation.
• To identify predictors of in-hospital mortality in this patient population.

Main Methods:

• Analysis of arterial blood gas data (pH, PaCO2, bicarbonate) at 24 hours post-VA-ECMO.
• Classification of patients based on acid-base status.
• Multivariable logistic regression and machine learning for mortality prediction.

Main Results:

• Over 15,000 patients analyzed; 74.6% had no acidosis, 13.1% respiratory, 11.6% metabolic, and 0.7% combined.
• In-hospital mortality was 51.0% and increased with lower pH, bicarbonate, and base excess.
• Lowest pH metabolic acidosis cluster showed highest mortality (aOR 1.90).

Conclusions:

• Survival declines with worsening acidemia or metabolic acidosis despite VA-ECMO in cardiogenic shock.
• Metabolic parameters are significant, potentially modifiable prognostic factors.
• Early recognition and intervention for severe metabolic derangements are critical.