Central Venous Oxygen Saturation As A Mortality Marker In Septic Shock: An Observational Study

Sundrani Omprakash; Bhagat Chandrapal; Mishra Aparna; Sahare Kamalkishore

Volume : IX, Issue : VI, June - 2020

Central Venous Oxygen Saturation As A Mortality Marker In Septic Shock: An Observational Study

Sundrani Omprakash, Bhagat Chandrapal, Mishra Aparna, Sahare Kamalkishore

Abstract :

Background: Septic shock is a leading cause of morbidity and mortality. Central venous oxygen saturation (ScVO2) is a prognostic marker of patients in septic shock. It is influenced by the oxygen–carrying capacity of blood, organ perfusion and metabolic oxygen consumption. Tissue hypoxia may sometimes occur despite adequate global oxygen delivery. In such scenarios, ScVO2 can be useful to predict increased risk of mortality. In the previous studies on ScVO2, its importance as a tissue oxygen marker and its importance in critical care has been studied. It has not been viewed as a mortality marker previously. The present study conducted to explore the association of ScVO2 with 28 days mortality in patients with septic shock, admitted to the Critical Care Unit (CCU) and, to evaluate the usefulness of ScVO2 as a mortality marker. Materials and method: A prospective, observational study which was conducted on patients admitted to the CCU with septic shock. 76 patients were enrolled for study based on inclusion and exclusion criteria. Central venous sampling by central venous catheter (CVC) was done for initial ScVO2 value (T0) and was repeated after 6 hours of resuscitation for ScVO2 value (T6) to assess the response to resuscitation. All enrolled patients were observed for a period of 28 days and were divided into 2 groups based on the outcome: Group NS (Non–Survivor group, which included patients who did not survive at the end of 28 days) and Group S (Survivor group, which included patients who survived at the end of 28 days) and ScVO2 values were compared between the survivor and non–survivor group. Result: In our study, out of 76 patients, 44 patients (57.89%) were non–survivors and 32 patients (42.11%) were survivors. The mean Central Venous Oxygen Saturation (ScVO2) at the time of admission (T0) was 64.00 � 2.74% among non–survivors and 73.22 � 2.62% among survivors, and after six hours of resuscitation (T6) it was 63.30 � 2.91% among non–survivors and 73.97 � 2.31 % among survivors. The sensitivity of ScVO2 at T0 in terms of mortality for value < 70% was 88.64% and specificity was 81.25% (OR = 33.8, 95%CI = 9.34, 122.35) and sensitivity of ScVO2 at T6 in terms of mortality for value < 70% was 93.18% and specificity was 93.75% (OR = 205, 95%CI = 32.23, 1303.97), which reflected that patients with ScVO2 < 70% had a poor prognosis as compared to patients with ScVO2 > 70%. Conclusion: Central Venous Oxygen Saturation (ScVO2) values of less than 70% at the time of admission to CCU (T0) and six hours after the resuscitation (T6) was associated with higher 28 days mortality. From the observations and analysis of our study, it can be concluded that ScVO2 can be used as a predictor of mortality in patients of septic shock.