Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75%) and Group B (rSO2 < 75%).Seven and 5 patients were assigned to Group A and Group B, respectively.Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14) and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09) compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03). Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03).Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.Many authors have previously reported risk factors for aortic arch reconstruction in pediatric cardiac surgery including the Norwood operation for hypoplastic left heart syndrome [1,2]. A potential risk of complications such as neurologic deficits and renal dysfunction is still a controversy. Regional cerebral perfusion (RCP) has been shown to provide cerebral circulatory support during arch reconstruction, minimizing or avoiding deep hypothermic circulatory arrest (DHCA). The brain receives direct perfusion through the right common carotid artery and right vertebral artery. The ability of RCP to provide sub-diaphragmatic somatic circulatory support via collateral vessels (the arterial circle of Willis, internal mammary arteries, intercostal arteries, etc.) has previously been described in detail [3,4].Near-infrared spectroscopy (NIRS) is used to measure the oxygen saturation of hemoglobin in the blood vessels of the frontal cerebral cortex. This is a new method in which infrared light at 730 and 810 nm wave lengths is used to measure the absorption spe