Study SOLACE SEPSIS

Inclusion Criteria: * Subjects will be eligible for the trial if they meet all of the following criteria: 1. Age criteria: 18 - 90 years 2. Septic shock - Sepsis 3 criteria : 1. acute change in total SOFA score ≥ 2 due to infection 2. use of vasopressor drug to maintain target mean arterial pressure ≥ 65 mmHg 3. blood lactate level ≥ 2 mmol/L within last 24 hours 3. Likely need for fluid resuscitation 1. poor peripheral perfusion as evidenced by 2 out of 4: i. peripheral cyanosis with delayed capillary refill ≥ 3 seconds ii. low urinary output (\< 0.5 ml/kg/hour for at least 6 hours) iii. central venous O2 saturation \< 70% iv. clouded sensorium/poor mentation 2. dynamic assessment of preload responsiveness as evidenced by 1 out of 3: i. positive passive leg raising test ii. pulse pressure variation and / or stroke volume variation2, both \> 12% iii. distensibility index of inferior vena caval diameter \> 12% 4. Signed the relevant informed consent form Exclusion Criteria: * Subjects will not be eligible for the trial if they meet any of the following criteria: 1. Poor transthoracic echo windows 2. Actual body weight \> 160 kg 3. Hypernatremia: \[Na\] \> 150 mEq/L 4. Cardiac tamponade 5. Uncorrected severe valvular heart disease or life-threatening arrhythmia 6. Moribund patients likely to die before the study protocol is completed 7. Patients with absolute indication for immediate acute hemodialysis/hemofiltration (within 2 hrs) based on pH \< 7.0, K \> 7.0mmol/L 8. Severe liver dysfunction defined by total serum bilirubin \> 120 umol/l 9. Pregnancy and lactation