A Study Of Significance Of Continuous Monitoring Of Jugular Venous Oxygen Saturation And The Effect Of Mild Hypothermia On It In Patients With Severe Traumatic Brain Injury

Objective: Significance of continuous monitoring of jugular venous oxygen saturation (SJVO2) and the effect of mild hypothermia on it in patients with severe traumatic brain injury (sTBI) were studied. Methods: 36 patients with sTBI (GCS<8 ) were divided into normalthermia control group (NT, n=12) and mild hypothermia group (HT, n=24), then continuous monitoring of SjvO2 in all patients was performed for 24-52 hours beginning within 6-24 hours after injury . In the same time, PbtO2 , ICP and other parameters of cerebral metabolism in patients of HT were measured , and the role of changes of SjVC>2 , the effect of mild hypothermia and factors which effect on SjvO2 ,and the relationship ofSjyO2 to outcome were analysed.Results: 1) In the acute phase of sTBI , the mean SjVO2 of the NT=35.33+ 10.30%, the mean SjvO2=43.04+20.63% in the HT, there was no significant difference between the two groups (p>0.05).2) At 48 hours SjvO2 after injury (SjvO2=47.58+5.83%) of NT was higher than those in the early time after injury(P<0.01). SjVO2 (SjvO2=58.33+14.33%) was higher than those in the early time after injury. 3) SjVO2 after mild hypothermia treatment was higher than those of control in the same time (P<0.05). 4) There was linear positive correlation between SJVO2and PbtO2 in HT (r=0.9871 P<0.05). 5) The outcome was evaluated at 3 months after injury. Outcome of HT was better than those of control group.6)According SjVO2 values after injury, the patients of HT were divided into high SjVO2 group, normal SjVO2 group and low SjVO2 group , and the outcome were evaluated , respectively. The outcome of normal SjVO2 group was better than low group and obviously high SjVO2 group was worse than normal and low SjvO2 group.Conclusion: 1) The SjVO2 of most sTBI patients was decreased after injury, Low value of SjvO2 was important information of cerebral anoxia , and it reflected the dynamic balance between brain oxygen delivery and/or brain oxygen metabolism. The value of SjVO2 of patients would affect patients' outcome. 2) The patients who had an obviously high SjVO2 would have a worse prognosis. This is thedescent of brain oxygen metabolism rate, finally resulted in severe brain anoxia, the prognosis would be affected . 3) Mild hypothermia therapy may improve PbtO2, and it may be a cerebroprotective mechanisms of hypothermia. 4) Continuous monitoring of SjVO2, which is simple and safe , could give a signal of brain the condition of brain oxygen metabolism associated with PbtO2, and it is an important means of monitoring of brain oxygen metabolism , guiding treatment and evaluating prognosis in patients with sTBI.