Background Neonatal extracorporal membrane oxygenation (ECMO) for pulmonary failure is characterised by small cannulas and low flow rates. Novel rotary pumps with diagonal blood flow and a reduced priming volume are now available. Bench studies in different in-vitro models and the short-term use for cardio-pulmonary bypass in paediatric patients are encouraging. However, little data exist on the effect of these devices on hemolysis in the defined group of neonates with respiratory failure.
Design We prospectively studied circuit settings, plasma-free haemoglobin (fHb), lactatdehydrogenase and coagulation activation in neonates receiving veno-arterial ECMO due to respiratory failure with a novel diagonal pump system.
Results Eight newborns (3280 g [2700; 4380, Median; Range]) received veno-arterial ECMO through 8–10Fr venous and 8Fr arterial cannulas appropriate for neck vessels. All infants were maintained on a centrifugal pump system for 4.3d (2; 7.3). Median flow rate and venous cannula pressure were 259 ml/min (215; 314), and -9 cm H2O (-50; -1) respectively. The median revolutions per minute of the pump were 4774 (4008; 6801). Mild hemolysis was detected within 24 h in all patients [median fHb 12.1 mg/dl (7.0; 70.9)] with a further increase after 48 hrs. Two patients (25%) developed disseminated intravascular coagulation and persistent moderate hemolysis.
Conclusion Our in vivo data support previous in vitro studies by demonstrating that the use of a centrifugal pump on small venous and arterial cannula appears to be safe and effective for neonatal ECMO. Yet, ECMO for more than 48 hrs holds the risk for an increased hemolysis and disseminated intravascular coagulation.