Objective Several clinical and experimental animal studies indicate that resuscitation with 100% oxygen increases brain injury and induces inflammation in vital organs. Elevated levels of the cytokine interleukin (IL)-6 have been observed in a number of pathological conditions including inflammation. Studies indicate that phytochemicals may protect against reoxygenation injury in the newborn. Our aim was to determine whether resuscitation with 100% oxygen after hypoxia generates higher levels of IL-6 in brain than resuscitation with 21% oxygen. We also wanted to examine if intravenous administration of phytochemicals given prior to hypoxia would have an additional effect.
Methods Forty newborn Noroc piglets were randomized to hypoxia or control groups and pretreatment with phytochemicals or placebo. The phytochemical solution contained 10 different biological active molecules with antioxidative properties. The piglets were given hypoxia and resuscitated with either 21% or 100% oxygen for 30 min and then observed with 21% oxygen for 120 min.
Results IL-6 increased significantly in frontal cortex of the brain for the 100% oxygen group compared to the 21% oxygen group. The adjusted difference was 28.0 (95% CI: 1.9 to 54.1, p = 0.041). IL-6 was not significantly related to phytochemicals (p = 0.836).
Conclusions Resuscitation after hypoxia with 21% oxygen induces less IL-6 in frontal cortex of newborn piglet brain than resuscitation with 100% oxygen. Intravenously administered phytochemicals did not have an additional effect. The potential effects of phytochemicals in this model are being further investigated.