Prognostic effects of microcirculation-assisted adjustment of venoarterial blood flow in extracorporeal membrane oxygenation: A prospective, pilot, randomized controlled trial.

Objective: The study explored the clinical efficacy of microcirculation-assisted blood flow adjustment in patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO).

Methods: This prospective, pilot, randomized controlled trial was conducted from 2018 to 2021; enrolled patients were randomly assigned to the microcirculation or control group at a 1:1 ratio. Microcirculatory and clinical data were collected within 24 h (T1) and at 24-48 h (T2), 48-72 h (T3), and 72-96 h (T4) after ECMO initiation and were compared between the groups following the intention-to-treat (ITT) principle. The primary outcome was the Sequential Organ Failure Assessment (SOFA) score at T2. In addition to ITT analysis, analysis based on the as-treated (AT) principle was performed.

Results: A total of 35 patients were enrolled in this study. At T2, the SOFA score did not significantly differ between the microcirculation and control groups (16 [14.8-17] vs. 16 [12.5-18], P = 0.782). Generalized estimating equation analysis demonstrated a significantly greater reduction in the SOFA score over time in the microcirculation-AT group than in the control-AT group (estimated difference: -0.767, standard error: 0.327, P = 0.019). The lactate level at T2 was significantly lower in the microcirculation-AT group (2.7 [2.0-3.6] vs. 4.1 [3.0-6.6] mmol/L, P = 0.029). No significant difference in the 30-day survival rate was noted between the groups.

Conclusion: This prospective pilot study demonstrated the feasibility of microcirculation-assisted VA-ECMO blood flow adjustment despite no significant clinical benefit for critically ill patients. More efforts in personnel training and newer technologies may help achieve microcirculation optimization.