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

We examined the hypothesis that higher cerebral oxygen saturation (rSO2) during RCP is correlated with urinary output.

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 < or = 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.