Near-infrared spectroscopy and ultrasound as complementary methods for assessing organ and peripheral tissue perfusion in veno-arterial-ECMO patients.

Abstract

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is vital for stabilizing patients with severe cardiac and pulmonary failure. Effective management requires precise monitoring of organ perfusion and systemic physiologic status. Near-infrared spectroscopy (NIRS) and ultrasound (US) are emerging as key methods of assessment, but their combined utility remains underexplored in VA-ECMO patients.

Methods: A retrospective analysis was conducted on 267 patients who received VA-ECMO between June 2018 and July 2023. Patients were divided into two groups based on weaning success, defined as survival for more than 48 hours post-weaning with improved cardiac function. Weaning trials involved incremental reductions in VA-ECMO flow, monitored by mean arterial pressure and other clinical measurements. Data including demographics, clinical scores [Glasgow Coma Scale (GCS), Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA)], blood gas indicators, and NIRS and US metrics were collected and analyzed.

Results: Significant differences were observed in cerebral regional oxygen saturation (rSO₂) dynamics and echocardiographic parameters between the groups. The successful group demonstrated higher maximal ΔrSO₂ (29.57% ± 13.77) than the failure group (25.86% ± 6.39, P = 0.003) and a lower minimal rSO₂ (40.67% ± 15.87 vs. 43.9% ± 4.27, P = 0.010). Post-ECMO, the successful group exhibited a higher cardiac index (CI, 2.47 L/min/m² ± 0.74) compared to the failure group (2.26 L/min/m² ± 0.61, P = 0.018). Pre-weaning, the successful group displayed lower left ventricular ejection fraction (LVEF, 32.06% ± 4.64) versus the failure group (34.55% ± 8.45, P = 0.016), yet post-weaning, it was higher (33.46% ± 4.85) than in the failure group (31.28% ± 7.37, P = 0.017). Additionally, the left ventricular outflow tract velocity-time integral (LVOT-VTI) pre-weaning was significantly lower in the successful group (14.95 cm ± 2.98) compared to the failure group (17.35 cm ± 7.22, P = 0.006).

Conclusion: NIRS and US were found to beconsistent and complementary modalities for assessing perfusion and cardiac function in VA-ECMO patients.