How Cerebral Oxygenation Correlates, Measured at Various Cranial Points, Frontally and Occipital in Children Under 1 Years Old, During General Anesthesia and Surgery

Children who undergo surgery routinely for surgery that risk high levels of circulatory changes (eg heart surgery) is currently used routinely monitoring as regional oxygenation technology of the brain (NIRS). Near infrared spectroscopy (NIRS) is a technique for measuring regional oxygen saturation, indirect autoregulation of brain. We know that reduced oxygenation of the brain can occur with severe immediate blood loss. We in the research group has been able to note that in children who undergo surgery for cranioplasty interventions <1 year old, when they have ongoing excessive bleeding, decreases oxygenation in the brain and sometimes sharply before we can replace the loss of blood, even the blood pressure can be adequately maintained. Perioperative hypovolemia is a risk factor upset autoregulation of brain. Respect of which the mean arterial pressure (MAP) required to maintain intact autoregulation during general anesthesia still lacks a scientific consensus.

By illuminating the skin and underlying tissue with infrared light in the spectra of 700 to 1100nm, it is possible to measure regional oxygen saturation in various tissues. At cerebral measuring sensor is placed frontally, just below the hairline. INVOS then returns the absolute values of cerebral oxygen saturation frontally in the area where the sensor is placed.

A frontal placement may in some cases be impractical / impossible and thus limits the ability to monitor the brains of children with different types of surgery or body positions. At certain cranioplastic intervention surgery a frontal placement is not always possible, partly because of surgical technic reasons, but also that the child may have to lie prone during surgery. An alternative placement of INVOS sensor could mean greater opportunities to monitor cerebral oxygen saturation and thus increase patient safety within the mentioned categories of patients. An occipital location is practically possible in many cases. The purpose of this study is to investigate whether a occipital located sensor can measure cerebral oxygen saturation in a reliable manner.