Benefits of a lower hematocrit during extracorporeal membrane oxygenation?

M. P. Griffin, P. K. Minifee, C. W. Daeschner 3rd and J. B. Zwischenberger
Department of Pediatrics, University of Texas Medical Branch, Galveston.

OBJECTIVE--To determine the possible benefits of maintaining a lower hematocrit than that normally used (0.35 vs 0.45) in neonates treated with extracorporeal membrane oxygenation. DESIGN--Randomized cohort. SETTING--Neonatal and pediatric intensive care units at a university hospital. PARTICIPANTS--Twenty neonates who met criteria for receiving extracorporeal membrane oxygenation from May 1988 to March 1990. INTERVENTIONS--Hematocrits were maintained at 0.35 for neonates in group 1 and 0.45 for neonates in group 2. MEASUREMENTS/MAIN RESULTS--Hematocrits were measured every 4 hours. Visible clots in the major circuit components were recorded. Infants in group 1 received (mean +/- SD) 2.5 +/- 0.6 mL of packed red blood cells per hour of extracorporeal membrane oxygenation while infants in group 2 received 3.8 +/- 0.9 mL of packed red blood cells per hour of extracorporeal membrane oxygenation. In group 1, clots were noted in six of 10 oxygenators and five of 10 bladder reservoirs. In group 2, clots were found in all 10 oxygenators and bladder reservoirs. CONCLUSIONS--Neonates' hematocrits can be maintained safely at 0.35 during extracorporeal membrane oxygenation with significantly less exposure to packed red blood cells and less clotting in the circuit.