Responses of cerebral blood volume and oxygenation to carotid ligation and hypoxia in young rabbits: near-infrared spectroscopy study.

After ligation of the bilateral common carotid arteries with exposure to hypoxia in young rabbits, cerebral blood oxyhemoglobin, deoxyhemoglobin, and total hemoglobin were measured by near-infrared spectroscopy. Ligation of common carotid arteries decreased oxyhemoglobin, increased deoxyhemoglobin, and slightly decreased total hemoglobin. Exposure to hypoxia with bilateral carotid ligation more remarkably decreased oxyhemoglobin and increased deoxyhemoglobin than that without carotid ligation. However, the total cerebral blood volume did not change very much. This marked reduction in the cerebral oxygenation may cause brain damage and may be an important monitoring marker for the prevention of hypoxic-ischemic encephalopathy.