The Clinical Significance Of Regional Oxygenation Saturation And Its Derived Variables In Early Diagnosis Of Sepsis-associated Encephalopathy

Objective:To investigate the clinical significance of regional oxygenation saturation?r SO₂?and its derived variables in early diagnosis of sepsis-associated encephalopathy?SAE?.We also sought to investigate the influencing factors of regional oxyhemoglobin saturation.Methods:Adult patients??18 years?admitted<24 h to intensive care unit were eligible if they had sepsis.Patients underwent cerebral oxygen saturation?S_cO₂?and thenar muscle oxygen saturation?S_mO₂?monitoring with the tissue oxygenation monitor in the first 24 hours of ICU admission and the muscle-cerebral oxygen saturation gradient(S_m-cO₂)was calculated.Systolic blood pressure?SBP?,diastolic blood pressure?DBP?,mean arterial pressure?MAP?,and heart rate?HR?were concurrently recorded.Clinically ordered arterial and central venous blood gas were also documented and will include PH,concentration of hemoglobin?Hb?,partial pressure of arterial O₂?P_aO₂?and CO₂?P_aCO₂?,arterial blood oxygen saturation?S_aO₂?,central venous oxygen saturation(S_cvO₂),partial pressure of central venous blood CO₂(P_cvCO₂),blood lactic acid?Lac?,difference between central venous and arterial PCO₂(P_cv-aCO₂).All patients were screened daily with the Confusion Assessment Method for the ICU?CAM-ICU?scores for their consciousness level.Patients were divided into two groups according to CAM-ICU:Those with CAM-ICU positive represented the SAE group,and those with negative were allocated to the NE group.Results:Thirty-two patients with sepsis were studied,eighteen in the SAE group and fourteen in the NE group.The incidence of SAE was 56%and the 28-day mortality rate was 56%.There was no significant difference between the two groups in gender,age?year?,SBP,DBP,MAP,HR,P_aO₂,Lac,28-day mortality in the SAE group were higher than those in the NE higher in group SAE than that in group NE?P<0.05?.No significant differences in S_cO₂ were found between groups?P>0.05?.The accuracy of S_cO2 in diagnosing SAE was low,and the area under the receiver's operating characteristic?ROC?curve?AUC?was less than 0.7.S_mO₂ and S_m-cO₂ were more accurate in diagnosing SAE,and the AUC was greater than 0.7.The cut-off value of S_mO₂ in the diagnosis of SAE was 60.3%,and the sensitivity and specificity were 83.3%and 71.5%,respectively.The cut-off value of S_m-cO₂ in the diagnosis of SAE was 2.23%,and the sensitivity and specificity were 61.1%and 78.6%,respectively.S_cO₂ was not significantly correlated positively with SBP,DBP,MAP and S_cvO₂?r=0.524,0.531,0.594 and 0.526,P=0.002,0.002,0.000,0.002?.S_mO₂ was not significantly correlated with SBP,MAP,S_aO₂,PO₂,PCO₂,Hb,PH and Lac?P>0.05?.S_mO₂ correlated well with DBP,S_cvO₂and age.?r=0.507,0.627 and?0.473,P=0.003,0.000 and0.006?.Conclusions:Regional oxygen saturation and its derived parameters can be used in the early diagnosis of sepsis related encephalopathy.r SO₂ is affected by blood pressure parameters and central venous oxygen saturation.Besides,S_mO₂is affected by age.