Background and Goal of the study. Despite an increased survival rate, neonatal heart surgery still entails considerable morbidity. The aim of the study was to identify critical cerebral and splanchnic desaturation periods during congenital heart surgery with and without the use of cardiopulmonary bypass, in order to propose tailored treatment guidelines.
Materials and Methods. Neonates with transposition of the great arteries or aortic coarctation were eligible for this prospective observational study. Cerebral and splanchnic saturation was measured with near-infrared spectroscopy (Nonin Equanox™ 7600). Eleven potential jeopardizing events were evaluated. Differences between the two surgical groups were evaluated with the independent samples t-test. Changes over time were assessed with a linear mixed model.
Results and Discussion. Twelve neonates undergoing arterial switch repair (7±4 days, 3.1±0.4 kg) and 11 coarctation patients (12±6 days, 3.1±0.7 kg) were studied. Two patients (9%) had an absolute decrease in cerebral saturation below 50%. Eight patients (35%) showed a relative decrease of >20% from baseline. In the TGA group the main risk periods for cerebral desaturation were arterial and venous cannulation and start of cardiopulmonary bypass. Risk moments in both groups were transfer to intensive care and extubation. The two groups were only significantly different during aortic cross-clamping (Cerebral saturation: 72±8% vs 80±5%, p=0.012, and renal saturation: 84±12% vs 54±11%, p<0.001, for TGA and coarctation, respectively).
Perioperative desaturations were short lasting and in response to specific events. This might suggest a high standard of perioperative care.
Conclusion. Cerebral and splanchnic desaturations were linked to specific, predictable perioperative events. Preventive measures and a tailored treatment algorithm might diminish the risk for perioperative desaturation.

Assessment of perioperative critical cerebral and splanchnic desaturation periods during neonatal heart surgery