Abstract
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. The conventional biomarker for hypoperfusion in septic shock is elevated lactate levels and though it predicts mortality, its specificity is low. As a part of pathophysiological mechanism of septic shock, there is deregulation of renin angiotension aldosterone pathway and as a surrogate we studied plasma renin activity (PRA) and its performance weighing lactate kinetics in shock reversal in patients with septic shock. OBJECTIVES: Primary outcome: Predictor of ICU mortality. Secondary outcome: Number of vasopressor days. Incidence of acute kidney injury. ICU length of stay. METHODOLOGY: Our study design is single centered, prospective, observational, non interventional study. Ethical committee approval and CTRI enrolment were done prior to recruitment. As an interim analysis, we enrolled 30 adult patients with septic shock as per sepsis-3 definition within 48 hours of diagnosis. Blood samples of PRA and lactates were sent for analysis at admission and at 6 hours. Rest of the management was left to the discretion of the treating intensivist. Statistical analysis was done using SPSS software version 27. RESULTS: The demographic profile was comparable between both groups. Mean PRA levels among non survivors were 15.05 ± 9.3 pg/ml and 39.01 ± 8.5pg/ml at admission and at 6 hours respectively whereas there is no change in the absolute values of lactate at both time frames, 3.8 ±2.7 mmol/L and 3.4 ± 1.92 mmol/L at admission and at 6 hours respectively. Among survivors mean PRA were 1.61 ± 2.35pg/ml and 8.15 ±11.4 pg/ml at admission and at 6 hours respectively and lactate levels were 1.74± 0.56 mmol/L and 1.95 ±1.29 mmol/L at admission and at 6 hours respectively (Fig 1). Both PRA and blood lactates at two different time points, at admission and 6 hours predicted survival but the statistical significance of renin outperformed lactates at both time points (p value <0.01 for PRA at 0 and 6 hours versus p value of 0.002 and 0.016 at admission and at 6 hours for lactate). Receiver operating curve analysis could not be performed for the limitations in sample size being an interim analysis. Secondary analysis showed, though, that both predicted mortality, length of ICU stay were uninfluenced by these biomarkers. Moreover acute kidney injury at day 2 as per KDIGO definition predicts mortality in our study population (p value 0.035). Days spent on vasopressors did not correlate to outcomes. CONCLUSION: Although both PRA and lactates predicts mortality, PRA independently is a better outcome predictor than lactates when assessing in-hospital mortality in patients with septic shock.