Comparison of Diastolic Shock Index with That of Lactates in Predicting Outcomes In Septic Shock – A Prospective Study

INTRODUCTION: Septic shock is defined as a subset of sepsis in which particularly profound circulatory, cellular and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone.(1) The conventional biomarker for hypoperfusion in septic shock is elevated lactate levels and though it predicts mortality, its specificity is low.(2) Being a vasodilatory shock, diastolic pressure is a better surrogate of vascular status and the utility of diastolic shock index (DSI) is a novel concept3 recently proposed in the setting of septic shock. We studied DSI and its comparison with lactates in shock reversal in patients with septic shock. AIMS/OBJECTIVES OF THE STUDY: Primary outcome: 1. Predictor of ICU survival Secondary outcome. 2. Number of vasopressor days. 3. ICU length of stay. MATERIALS AND METHODS: Our study design is single centered, prospective and observational. Scientific Research Committee committee approval was done prior to recruitment. We enrolled 30 adult patients with septic shock as per sepsis-3 definition 1 before initiation of vasopressors. DSI was calculated as ratio of heart rate to diastolic blood pressure. DSI and lactates were analysed at the time of diagnosing septic shock. Those who present to us after initiation of vasopressors were excluded from the study. Rest management were uninterrupted by the investigator and lies within the discretion of the treating intensivist. Statistical analysis were done using SPSS software version 26. RESULTS: The demographic profile is comparable between both groups. The mean survival rate of our study population was 54%. Mean admission DSI levels among non survivors and survivors were 2.81 ± 0.51 and 1.87 ± 0.32 respectively and the mean lactate levels among non survivors and survivors were 3.66 ± 2.66 mmol/L and 1.78 ± 0.58 mmol/L respectively. Both DSI and blood lactates at the time of diagnosis of septic shock predicted survival but the statistical significance of DSI outperformed lactates (p value 0.001 for DSI versus 0.05 for lactates respectively). Receiver operating curve analysis could not be performed for the limitations in sample size. Secondary analysis showed, a higher admission DSI is associated with increased number of days spent on vasopressors (p value 0.01) whereas no such association was observed with lactates (p value 0.07) but there is no influence on the length of stay in ICU. There is no significant correlation of mean arterial pressure to any of our outcome parameters. CONCLUSIONS: Although both DSI and lactates predicts mortality when assessing in-hospital mortality in patients with septic shock, DSI is a simple, non invasive bed side tool that can be utilized in prognosticating the patients and predicting the number of days on vasopressors.