Objective To determine the effect of intravascular fluid infusions on cerebral oxygenation and hemodynamics during veno-arterial extracorporeal membrane oxygenation (va-ECMO).
Methods Neonates treated with va-ECMO were studied during intravascular infusions of normal saline and erythrocytes (due to hypovolemia and low hemoglobin level, respectively). Mean arterial blood pressure (MAP) was continuously monitored. Concentration changes of oxyhemoglobin (cO2Hb) and deoxyhemoglobin (cHHb) were assessed using near infrared spectrophotometry. Changes in cHbD ( = cO2Hb–cHHb) represent changes in cerebral blood flow (CBF) and changes in ctHb ( = cO2Hb+cHHb) reflect changes in cerebral blood volume (CBV). Mean changes of MAP, cHbD and ctHb at the end of the fluid infusion as compared to the beginning were statistically analyzed using the Wilcoxon signed rank test.
Results 16 measurements of intravascular fluid infusions (9 saline and 7 erythrocytes infusions, volumes 20–50 mL, infusion duration 1–3 min) were obtained in 5 patients. Intravascular fluid infusions resulted in significant increases of MAP, cHbD and ctHb (see fig).
Rapid intravascular fluid infusions during va-ECMO result in significant increases of MAP and simultaneous increases of CBF and CBV. This finding indicates disturbed cerebral autoregulation. In our previous study a relationship between frequent intravascular fluid infusions during va-ECMO and development of intracerebral hemorrhage (ICH) has been shown. We propose that due to disturbed autoregulation, rapid intravascular volume replacement therapy might be a risk factor for development of ICH during va-ECMO.