| Purpose:To investigate the use of Central Venous Oxygen Saturation (ScvO2) test in evaluating the Volume responsiveness, the state of illness and prognosis in Volume-resuscitation patients.Methods:The measurements being analyzed in this study were collected from 46 patients, which were admitted to the Serious Intensive Care Unit (SICU) and Emergency Intensive Care Unit (EICU) in The 2nd Affiliated Hospital of Kunming Medical University from January 2013 to January 2014. Several physiological indexes were examined in this study. Patients were given 250ml of physiological saline for Rapid-infusion experiment once being admitted; the measurements of ScvO2were recorded before and after saline was given. The correlations between change in ScvO2 and the Reaction of tissue perfusion index (lactic acid), as well as Reaction flow index (Cardiac Output (CO).46 patients were divided into two groups, survival (n=41) and death (n=5) based on the prognosis, on which the statistical tests were performed to investigate the significance of difference in ScvO2 between two groups. Meanwhile, patients were also grouped based on the results from Volume-load test, volume-resuscitation responsive when CO has increased more than 15% and volume-resuscitation unresponsive when CO increment was less than 15%. Central Venous Pressure (CVP), Heart Rate (HR), Mean Arterial Pressure (MAP) were compared between two groups and the correlations among the measurements were analyzed. According to the score of Acute Physiological and Chronic Health Evaluation Ⅱ (APACHE Ⅱ), patients were grouped into three categories:APACHE Ⅱ <15,15≤APACHE Ⅱ≤20, APACHE Ⅱ>20. The change in ScvO2 in all three groups were collected and compared for variation. The ΔScvO2, ΔCVP, ΔMAP and ΔSVV were calculated based on the area under curve (AUC) of Receiver Operating Curve (ROC) and the difference in diagnostic value among four parameters were compared. According to different ScvO2 value, patients were again divided into three groups:Low ScvO2 (< 70%), Moderate ScvO2 (< 70-80%), High ScvO2 (> 80%) to compare the time difference in mechanical ventilation and being hospitalized in Intensive Care Unit (ICU), as well as the rate of death. All data collected has been statistically analyzed using SPSS 17.0 program, which primarily evaluated the mean, standard deviation, percentiles and median. Independent t-test, Chi-square test and ANOVA were used to compare sorting parameter and continuous variable. We are using Receiver Operation Characteristic Curve (ROCC) to identify the cutoff value of ScvO2 in predicting the reactive capacity, as well as its sensitivity and specificity. We are evaluating the predictive value of early volume resuscitation according to the Area Under Receiver Operating Curve (AUROC). The statistically significant difference is recognized when p value is observed less than 0.05.Results:Statistically significant difference was observed before and after fluid resuscitation for both ScvO2 and lac (lactic acid). There was correlation observed between the reaction of tissue perfusion index (Lactic acid) and ScvO2. ScvO2 and the reaction flow index, CO were positively correlated, whereas the reaction flow index. According to the analysis between survival (n=41) and death (n=5) groups, the difference in both APACHE Ⅱ score and Sequential Organ Failure Assessment (SOFA) score were observed and APACHE Ⅱ score and SOFA score of survival group were higher than that of death groups; lac of survival was recovered after treatment and observed a better level than lac of death group. ScvO2 difference between two groups was statistically significant (p= 0.029). ΔScvO2 was able to predict the volume responsiveness from the group with ΔCO≥15% before and after the resuscitation (AUROC=0.822>0.5, cutoff value 2.1%, sensitivity 90%, Specificity 73.1%). For the predictive value of prognosis, there was significant difference in CO, lac, ScvO2 after volume resuscitation. The death rate among Low ScvO2 (<70%), Moderate ScvO2 (< 70-80%) and High ScvO2 (>80%) in 28 days was observed no statistically significance. However, statistically significant difference was observed in ScvO2, HR, CO before and after volume resuscitation between Shock and Operation groups. When ScvO2 and ΔScvO2 were calculated using AUROC, ΔScvO2 was indicated having predictive value in prognosis (AUROC=0.674> 0.05, cutoff value 2.9%, sensitivity 85.7%, specificity 53.8%). From death rate analysis of categories with three different APACHE Ⅱ score range (APACHE Ⅱ<15,15≤APACHE Ⅱ≤20, APACHE Ⅱ>20), the ANOVA test showed a value of 2.389, p=0.303> 0.05 indicating no statistically significant difference observed. The correlation between ScvO2 and patient off-line time examined in the following three groups, Low ScvO2 (<70%), Moderate ScvO2 (<70-80%), High ScvO2 (> 80%) were showing no statistical significance. Comparisons between each of two groups showed a p value that was larger than 0.05 without exceptions.Conclusion:ScvO2 is one of the metabolic indexes that are able to fairly accurate reflect the oxygen metabolism state. ScvO2 reflects whether the balance of oxygen supply and oxygen demand is maintained in the physiological system. ΔScvO2 can be used as an effective monitoring index in predicting the volume responsiveness. By dynamically monitoring ScvO2, circulating blood flow and tissue perfusion can be dynamically evaluated, and it also has predictive value in prognosis. |
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