Randomized trial of hematocrit 25% versus 35% during hypothermic cardiopulmonary bypass in infant heart surgery.
OBJECTIVE
We previously reported that postoperative hemodynamics and developmental outcomes were better among infants randomized to a higher hematocrit value during hypothermic cardiopulmonary bypass. However, worse outcomes were concentrated in patients with hematocrit values of 20% or below, and the benefits of hematocrit values higher than 25% were uncertain.


METHODS
We compared perioperative hemodynamics and, at 1 year, developmental outcome and brain magnetic resonance imaging in a single-center, randomized trial of hemodilution to a hematocrit value of 25% versus 35% during hypothermic radiopulmonary bypass for reparative heart surgery in infants undergoing 2-ventricle repairs without aortic arch obstruction.


RESULTS
Among 124 subjects, 56 were assigned to the lower-hematocrit strategy (24.8% +/- 3.1%, mean +/- SD) and 68 to the higher-hematocrit strategy (32.6% +/- 3.5%). Infants randomized to the 25% strategy, compared with the 35% strategy, had a more positive intraoperative fluid balance (P = .007) and lower regional cerebral oxygen saturation at 10 minutes after cooling (P = .04) and onset of low flow (P = .03). Infants with dextro-transposition of the great arteries in the 25% group had significantly longer hospital stay. Other postoperative outcomes, blood product usage, and adverse events were similar in the treatment groups. At age 1 year (n = 106), the treatment groups had similar scores on the Psychomotor and Mental Development Indexes of the Bayley Scales; both groups scored significantly worse than population norms.


CONCLUSIONS
Hemodilution to hematocrit levels of 35% compared with those of 25% had no major benefits or risks overall among infants undergoing 2-ventricle repair. Developmental outcomes at age 1 year in both randomized groups were below those in the normative population.
Newburger
Jane W
JW
Department of Cardiology, Children's Hospital Boston, Boston, Mass 02115, USA. jane.newburger@cardio.chboston.org
Jonas
Richard A
RA
Soul
Janet
J
Kussman
Barry D
BD
Bellinger
David C
DC
Laussen
Peter C
PC
Robertson
Richard
R
Mayer
John E
JE
del Nido
Pedro J
PJ
Bacha
Emile A
EA
Forbess
Joseph M
JM
Pigula
Frank
F
Roth
Stephen J
SJ
Visconti
Karen J
KJ
du Plessis
Adre J
AJ
Farrell
David M
DM
McGrath
Ellen
E
Rappaport
Leonard A
LA
Wypij
David
D
D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000379:methods*; D002423:Cause of Death; D002493:Central Nervous System Diseases / Q000453:epidemiology / Q000209:etiology; D002658:Developmental Disabilities / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery*; D006345:Heart Septal Defects, Ventricular / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D006400:Hematocrit; D006438:Hemodilution / Q000009:adverse effects*; D006801:Humans; D007036:Hypothermia, Induced; D015994:Incidence; D007223:Infant; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology; D011336:Probability; D018570:Risk Assessment; D016019:Survival Analysis; D013771:Tetralogy of Fallot / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D013997:Time Factors; D014188:Transposition of Great Vessels / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D016896:Treatment Outcome