Measuring brain tissue oxygenation compared with jugular venous oxygen saturation for monitoring cerebral oxygenation after traumatic brain injury

Jugular bulb oximetry is the most widely used method of monitoring cerebral oxygenation. More recently, measurement of brain tissue oxygenation has be en reported in head-injured patients. We compared the changes in brain tiss ue oxygen partial pressure (PbO2) with changes in jugular venous oxygen sat uration (SjVO(2)) in response to hyperventilation in areas of brain with an d without focal pathology. Thirteen patients with severe head injuries were studied. A multiparameter sensor was inserted into areas of brain with foc al pathology in five patients and outside areas of focal pathology in eight patients. A fiberoptic catheter was inserted into the right jugular bulb. Patients were hyperventilated in a stepwise manner from a PaCO2 of approxim ately 35 mm Hg to a PaCO2 of 22 mm Hg. There was no significant change in c erebral perfusion pressure or arterial partial pressure of oxygen with hype rventilation. In areas without focal pathology, there was a good correlatio n between changes in SjVO(2) and PbO2 (Delta SjVO(2) and Delta PbO2, r(2) = 0.69, P < 0.0001). In areas with focal pathology, there was no correlation between Delta SjVO(2), and Delta PbO2 (r(2) = 0.07, P = 0.23). In this stu dy, we demonstrated that measurement of local tissue oxygenation can highli ght focal differences in regional cerebral oxygenation that are disguised w hen measuring SjVO(2). Thus, monitoring of PbO2 is a useful addition to mul timodal monitoring of patients with traumatic head injury. Implications: Br ain oxygenation is currently monitored by using jugular bulb oximetry, whic h attracts a number of potential artifacts and may not reflect regional cha nges in oxygenation. We compared this method with measurement of brain tiss ue oxygenation using a multiparameter sensor inserted into brain tissue. Th e brain tissue monitor seemed to reflect regional brain oxygenation better than jugular bulb oximetry.