Elevated jugular venous oxygen saturation after severe head injury

Object. The aim of this study was to investigate the incidence of elevated (greater than or equal to 75%) jugular venous oxygen saturation (SjvO(2),) and its relationship to-cerebral hemodynamic and metabolic parameters and t o outcome after severe head injury. Methods. Data from 450 severely head injured patients admitted to the Neuro surgical Intensive Care Unit of Ben Taub General Hospital were analyzed ret rospectively. The SjvO(2), was measured in blood obtained from indwelling j ugular bulb catheters. Patients were classified into the following categori es: high (Group I), normal (Group II), or low SjvO(2), (Group III) if their mean SjvO(2), over the duration of monitoring was 75% or higher, 74 to 56% , or 55% or lower, respectively. A high SjvO(2), occurred in 19.1% of patients. There was no consistent rela tionship between SjvO(2), and simultaneous cerebral blood flow (CBF) or cer ebral perfusion pressure measurements. Compared with Groups II and III, the patients in Group I had a significantly higher CBF and lower cerebral meta bolic rate of oxygen (CMRO2. In Group I, the outcomes were death or persist ent vegetative state in 48.8% of patients and severe disability in 25.6%. T hese outcomes were significantly worse than for patients in Group II. Withi n Group I, the patients with a poor neurological outcome were older and mor e likely to have suffered a focal head injury; they demonstrated a lower CM RO2, and a greater rate of cerebral lactate production than the patients wh o attained a favorable outcome. Conclusions. Posttraumatic elevation of SjvO(2) is common but cannot be aut omatically equated with hyperemia. Instead, elevated SjvO(2), is a heteroge neous condition that is associated with poor outcome after head injury and may carry important implications for the management of comatose patients.