Vasopressor Dependency as A Predictor of Mortality in Septic Shock

INTRODUCTION: Septic shock ensues when sepsis-induced hypotension remains refractory to fluid resuscitation. Mean arterial pressure is the key determinant of increased tissue blood flow and perfusion. Guideline recommends initial target mean arterial pressure (MAP) of 65mm Hg over higher MAP targets. (3) Effective fluid resuscitation and vasopressor, are mainstay for maintaining the target MAP. The hemodynamic response of vasopressors to achieve a target MAP can be measured by vasopressor dependency (VD). OBJECTIVES: This study was conducted in septic shock patients to: 1. Assess the correlation between vasopressor dependency and 28-day mortality. 2. Classify septic shock patients based on vasopressor dependency (Vd). MATERIALS AND METHODS: This is a Prospective observational study conducted over a period of 1 year i.e September 2023 to August 2024. All consecutive adult patients (>18 years) with a diagnosis of septic shock were included in the study. Septic shock was diagnosed as per the sepsis-3 criteria by the treating physician. Lowest MAP during the first 24hrs after inclusion to the study was recorded. The highest/maximum dose of each vasopressor used in the same timeframe (1st 24 hours) was also recorded. Vasopressor inotrope score (VI) was calculated by using the formula = (Dose of dopamine × 0.01) + (Dose of dobutamine × 0.01) + (Dose of epinephrine) + (Dose of norepinephrine) + (Dose of phenylephrine X 0.1) + (Dose of vasopressin X 2.5) + (Dose of Metaraminol × 0.125) + (Dose of Angiotensin II × 10). All doses are in mcg/Kg/min except vasopressin, which is unit/hour. Vasopressor dependency (VD) was calculated as Patients were categorized into three groups according to the VD score, such as VD of < 0.5/mmHg as mild (VD1), 0.5 to 1/mmHg as moderate (VD2) and > 1/mm Hg as severe (VD3). RESULTS: Seventy three patients (73) of median age 54 years with IQR 37 – 66; were included in this study during this period. Demographic parameters and length of ICU stay are summarised in Table 1. 28-day mortality rate in VD1, VD2 and VD3 was 50%, 50% and 72% respectively. CONCLUSIONS: Patients with severe vasopressor dependency (Vd3) exhibited significantly higher 28-day mortality. This highlights the importance of vasopressor dependency as a predictive marker in septic shock management.