The primary outcome is brain relaxation scales , an indirect evaluation of ICP ; secondary endpoints include cerebral metabolism variables ( jugular venous oxygen saturation -LSB- SjvO ( @ ) -RSB- , arterial-jugular venous differences in oxygen -LSB- CajvO ( @ ) -RSB- , glucose -LSB- A-JvGD -RSB- , lactate -LSB- A-JvLD -RSB- , and cerebral extraction ratio for oxygen -LSB- CERO ( @ ) -RSB- ) and fluid volumes .