This retrospective study analyzed the current practice of blood transfusion-free open-heart surgery in 536 children weighing 5-20 kg undergoing surgery between 2004 and 2007. A miniaturized cardiopulmonary bypass (CPB) circuit was used (priming volume; 300 ml for the flow rate <1,500 ml/min; 550 ml for the flow rate of 1500-2300 ml/min). Modified ultrafiltration was routinely performed. Criteria for blood transfusion during CPB included a hematocrit of <20% and/or mixed venous oxygen saturation of <65%. Transfusion during CPB was avoided in 264 (49.3%) of the 536 patients (5-10 kg group, 29.0%; 11-15 kg group, 67.4%; 16-20 kg group, 80.8%). There was no neurological complication related to hemodilution. Multiple logistic regression analysis revealed that body weight, preoperative hematocrit, priming volume of CPB circuit, CPB time, and lowest hematocrit during CPB predict requirement of blood transfusion (p < 0.01). Transfusion rate was lowest in the atrial septal defect group (5.6%) and highest in tetralogy of Fallot group (78.7%), being associated with complexity of diagnosis and procedure required. Blood transfusion-free open-heart surgery may be achieved in the half of the patients weighing 5-20 kg, and further miniaturization of CPB circuit and refinement of perfusion strategy might reduce transfusion rate in patients <10 kg and/or with complex congenital heart disease.

Extracorporeal membrane oxygenation (ECMO) is an important circulatory assist for children with refractory cardiopulmonary dysfunction, but its role and indications after a stage 1 Norwood procedure are controversial. We assessed outcomes and risk factors in patients who underwent a Norwood palliation and ECMO at our institution. We retrospectively reviewed all patients who underwent a Norwood procedure and were supported with ECMO between January 1998 and January 2010. Of the 91 children who underwent a Norwood procedure during the study period, there were 15 postoperative runs of ECMO in 12 patients. The diagnoses of the patients included five with hypoplastic left heart syndrome, five with a hypoplastic left heart syndrome variant, and two with critical aortic stenosis. A total of four patients underwent bilateral pulmonary artery banding, and two patients underwent aortic valvuloplasty before the stage 1 Norwood procedure. The mean age of the patients was 28±30 days, and mean body weight was 2.6±0.5kg at the induction of ECMO. The indications for ECMO were low cardiac output in six children, circulatory collapse needing cardiopulmonary resuscitation in six children, and hypoxemia in three children. Five of the 12 patients were successfully weaned from ECMO. The significant risk factors for the inability to be weaned from ECMO were a history of circulatory collapse requiring cardiopulmonary resuscitation, and the induction of ECMO in the intensive care unit. Induction of ECMO may be considered earlier when hemodynamics are unstable in impaired patients following a stage 1 Norwood procedure to avoid circulatory collapse.

This study was undertaken to determine the impact of miniaturization of a cardiopulmonary bypass (CPB) circuit on blood transfusion and hemodynamics in neonatal open-heart surgery. Neonates (n = 102) undergoing open-heart surgery between 2002 and 2006 were included and divided into three groups: group 1 (n = 28), Dideco 902 oxygenator + 5/16" line; group 2 (n = 29), Dideco 901 oxygenator + 1/4" line; group3 (n = 45), Dideco 901 oxygenator + 3/16" arterial + 1/4" venous line. Amount of priming volume, blood and bicarbonate sodium use during CPB, and hemodynamics were compared. Priming volume in the groups 2 and 3 was significantly less compared with the group 1 (group 1, 575 +/- 37 ml; group 2, 328 +/- 12 ml, group 3, 326 +/- 5 ml, p < 0.05). Blood transfusion and bicarbonate sodium use during CPB in groups 2 and 3 were significantly less compared with group 1. Hemodynamics during CPB was comparable. There were no differences between groups 2 and 3 in any parameter. Miniaturization of the CPB circuit resulted in decrease in priming volume and subsequent reduction in blood and bicarbonate sodium use. Downsizing the lines had minimal impact on any of the parameters studied, and further efforts should be made to achieve neonatal open-heart surgery without blood transfusion.

Blood priming is necessary for cardiopulmonary bypass (CPB) in neonates to avoid excessive hemodilution; however, transfusion-related inflammation affects postCPB outcomes in neonatal open-heart surgery. We hypothesized that ultrafiltration of priming blood before CPB may reduce inflammatory mediators in priming blood and postCPB inflammatory responses, thereby improving cardiopulmonary function. Twelve 1-week-old piglets (3.5 +/- 0.2 kg) were divided into two groups. Group U (n = 6) employed the priming blood ultrafiltrated before CPB, but group N (n = 6) used the nonultrafiltrated blood. Cardiopulmonary bypass was performed for 2 hours and then modified ultrafiltration (MUF) was conducted. Data were acquired before CPB and after MUF. The values of K+, serotonin, and IL-8 in priming blood was significantly decreased after ultrafiltration (8.2 +/- 2.6 vs. 4.2 +/- 0.8 mEq/L, p < 0.01, 234 +/- 96 vs. 74 +/- 42 ng/ml, p < 0.01, 78.4 +/- 5.1 vs. 64.5 +/- 59.1 pg/ml, p < 0.05). Group U after MUF had lower thrombin-antithrombin complex levels (23.9 +/- 5.1 vs. 33.7 +/- 4.6 ng/ml, p < 0.01) and lower IL-8 levels in airway fluid (925 +/- 710 vs. 2495 +/- 1207 pg/ml, p < 0.05) than group N. Cardiac output and arterial PO2 after MUF in group U were also higher (1.13 +/- 0.21 vs. 0.69 +/- 0.22, p < 0.01, 340 +/- 190 vs. 149 +/- 84 mm Hg, p < 0.05). The ultrafiltration of blood priming before CPB attenuated activation of the coagulation pathway and inflammatory responses and preserved cardiopulmonary function in neonatal piglets.

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The high-flow management of cardiopulmonary bypass (CPB; >or=2.4 L/min/m(2)) is a standard strategy used at this institute for children with pulmonary atresia (PA) due to a fear that the blood flow may be diverted by the major/minor aortopulmonary-collateral-arteries and hypervascularization due to long-term hypoxia. The purpose of this study was to describe the validity of high-flow management in children with PA. The CPB records of 23 children with PA who underwent a definitive biventricular repair between Feb 2006 and Nov 2008 were retrospectively reviewed. The mean age at the operation was 33 +/- 22 months. The blood-pressure during bypass was controlled with the same protocol. The mean cooling-temperature was 28.4 +/- 3.7 degrees C. The mean minimum hematocrit was 25.0 +/- 3.4%. The mean maximum bypass flow index at the initiation, the mean maximum flow index during aortic cross-clamping, the mean minimum flow index during aortic cross-clamping, and the mean maximum flow index after rewarming were 3.1 +/- 0.5, 3.1 +/- 0.5, 2.6 +/- 0.4, and 3.2 +/- 0.4 L/min/m(2), respectively. The higher bypass flow indexes significantly correlated with the lower serum lactate levels. The lowest oxygen delivery during CPB had significant influences on the urine output during bypass (R = 0.547, P = 0.007), the serum lactate levels at the end of CPB (R = -0.442, P = 0.035), and the postoperative thoracic effusion (R = -0.459, P = 0.028). A bypass flow index of 2.4 L/min/m(2) may not be sufficient and the maximum requirement of bypass flow index may be 3.2 L/min/m(2) or more in this patient population.

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