The purpose of this study is to investigate the safety and efficacy of early administration of two different doses of dexamethasone in high risk septic patients.

The septic adult patients of high risk would be enrolled in 2 emergency departments.

Sepsis would be defined by Sepsis-3 definition. High risk is defined as initial systolic blood pressure less than 90 mmHg or blood lactate level over 2 mmol/L.

The enrolled patients would be randomized to 3 groups: control, low dose dexamethasone (0.1 mg/kg iv), and high dose dexamethasone (0.2mg/kg iv).

The study drug is blinded and administered after enrollment for 2 days. Sample size would be 102, considering 10% of drop-out rate, allocating 30 patients to each groups.

Efficacy would be evaluated as follows; 28 day and 90 day mortality, time to septic shock, time to shock reversal, administration of steroid according to guideline, ventilator free days, Continuous renal replacement, Length of stay in ICU or hospital, delta SOFA score on day 3 and day 7,

Safety would be evaluated as follows; Superinfection Gastrointestinal bleeding, Hyperglycemia, Hypernatremia

Inclusion Criteria:

• Sepsis defined by Sepsis-3 definition
• Initial systolic blood pressure < 90mmHg or blood lactate level >2mmol/L

Exclusion Criteria:

• advanced directive for "Do not resuscitation"
• recent systemic administration of glucocorticoid (4 weeks)
• recent systemic administration of chemotherapy (4 weeks)
• recent systemic administration of immunosuppressant (4 weeks)
• expected life less than 90 days
• Transferred from other hospital
• Sepsis diagnosed 24 hours after ED admission
• Use of etomidate in ED
• pregnant or on lactation
• no informed consent