Transcranial Doppler Ultrasound for Monitoring the Cerebral Hemodynamic Changes and Prognosticating Outcomes in Venoarterial Extracorporeal Membrane-Oxygenated Patients

Abstract

Objective: Patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) support may have cerebral hemodynamic changes whose impact on patient outcome are not fully elucidated. This study aims to evaluate the correlation between cerebral hemodynamic changes and prognostic outcome in patients during VA-ECMO.

Methods: Transcranial Doppler (TCD) ultrasound examination was performed to attain the systolic velocity (Vs), diastolic velocity (Vd), mean velocity (Vm), and pulsatility index (PI) of patients undergoing VA-ECMO. Cardiac ultrasound was also performed to assess the correlation between the left ventricular outflow tract velocity time integral (LVOT VTI), left ventricular ejection fraction (LVEF), and middle cerebral artery (MCA) with the systolic peak. Moreover, we assessed the predictive value of LVOT VTI and LVEF in patients with the systolic peak. Patients were divided into survival and death groups according to the 28-day survival period. Clinical data were compared between the two groups to investigate the effects of cerebral hemodynamic changes on the prognosis of VA-ECMO patients.

Results: We found that the patient's LVOT VTI and LVEF had high predictive values for the systolic peak of the right middle cerebral artery. The initial LVEF, Vs, Vd and PI, and lactate level as well as the MODS incidence rate difference were significantly different between the survival and death groups. In addition, the results showed that the initial Vs value was an independent risk factor for the prognosis of patients undergoing VA-ECMO.

Conclusions: Cerebral hemodynamic changes may occur in patients supported by VA-ECMO. In addition, a poor cerebral arterial pulsatile blood flow was closely correlated with an unfavorable outcome in these patients.

Figure 1

Correlation analysis of LVOT VTI, LVEF, and RMCA with the systolic peak.

Figure 2

The predictive value of LVOT VTI and LVEF for the occurrence of systolic peaks in the right middle cerebral arteries.

Figure 3

Univariate regression analysis of the variables affecting 28-day mortality of patients undergoing VA-ECMO.

Figure 4

The RMCA flow waveforms that can be observed during different cardiac functional states. (a) LVEF<10%, the RMCA had an advection. (b) 10%< LVEF <20%, there was a systolic spike in the right middle cerebral artery. (c) 20%< LVEF <30%, the systolic peak of the RMCA increased further, but the PI was still below the normal value. (d) LVEF >40%, the normal blood flow pattern of the RMCA.