Characterization of Cerebral Hemodynamics with TCD in Patients Undergoing VA-ECMO and VV-ECMO: a Prospective Observational Study

Background: Extracorporeal membrane oxygenation has a high risk of acute brain injury and resultant mortality. Transcranial Doppler characterizes cerebral hemodynamics in real time, but limited data exist on its interpretation in ECMO. Here, we report TCD mean flow velocity and pulsatility index in a large ECMO population. Methods: This was a prospective cohort study at a tertiary care center. The patients were adults on venoarterial ECMO or venovenous ECMO undergoing TCD studies. Results: A total of 135 patients underwent a total of 237 TCD studies while on VA-ECMO (n = 95, 70.3%) or VV-ECMO (n = 40, 29.6%). MFVs were captured reliably (approximately 90%) and were similar to a published healthy cohort in all vessels except the internal carotid artery. Presence of a recordable PI was strongly associated with ECMO mode (57% in VA vs. 95% in VV, p < 0.001). Absence of TCD pulsatility was associated with intraparenchymal hemorrhage (14.7 vs. 1.6%, p = 0.03) in VA-ECMO patients. Conclusions: Transcranial Doppler analysis in a single-center cohort of VA-ECMO and VV-ECMO patients demonstrates similar MFVs and PIs. Absence of PIs was associated with a higher frequency of intraparenchymal hemorrhage and a composite bleeding event. However, cautious interpretation and external validation is necessary for these findings with a multicenter study with a larger sample size.

Automated summary

This study reports the results of transcranial Doppler measurements of mean flow velocity and pulsatility index in a large ECMO population. The results suggest similar flow velocity and pulsatility index compared to a healthy population, but the absence of pulsatility index is associated with intraparenchymal hemorrhage. These findings require validation through a larger multicenter study.