Four-side near-infrared spectroscopy measured in a paediatric population during surgery for congenital heart disease.

In this study we monitored renal, hepatic and muscular oxygen saturations by near-infrared spectroscopy and we evaluated the correlation with variables that could affect tissue oxygenation in 16 paediatric patients during surgical heart procedure. We considered the following phases: 1) basal time (after induction of anaesthesia and before median sternotomy), 2) before starting cardiopulmonary bypass, 3) 15 min after starting it, 4) at half time, 5) 15 min before the end, 6) at the end, 7) 15 min after the end, and 8) 10 min before paediatric intensive care unit admission. Heart rate, mean arterial pressure, peripheral oxygen saturation, serum lactate, haemoglobin, blood gas analysis, and rectal temperature were registered. We found a decrease of all monitored regional saturations (rSO(2)) (cerebral P = 0.006, hepatic P = 0.005) before starting the bypass. After this time, cerebral saturation gradually increased without reaching the basal value; renal and liver saturations increased after starting bypass; muscular rSO(2) increased in the second half (P = 0.005). A statistically significative inverse correlation between cerebral rSO(2) and pH was observed. In conclusion, during paediatric heart surgery a vulnerable period was identified. We underline the necessity to monitor this phase.