Volume Kinetics of Fluid Resuscitation in Early Sepsis

Inclusion Criteria: A diagnosis of sepsis, as defined by the Sepsis-3 criteria and exhibiting sepsis-induced hypoperfusion prior to the administration of adequate volume resuscitation: * hypotension requiring norepinephrine to maintain a mean arterial blood pressure (MAP) either predefined by the clinician or at 65 mm Hg or higher and/or * a serum lactate level \>2 mmol/L (18mg/dL) and/or * acute oliguria defined as urine output \<0.5mL/kg/hr and/or * mottled skin and/or * capillary refill time \> 3 seconds. Exclusion Criteria: * Administration of at least 1 L of IV fluid in the last 6 hours prior to screening. All crystalloids, colloids and blood products that the patient has received are counted. * Known pregnancy. * Competing causes of lactic acidosis including: seizures within 3 hours of enrollment, use of linezolid or metformin or anti-retrovirals at the time of enrollment, carbon monoxide or cyanide poisoning, highly suspected or known ischemic bowel, and known mitochondrial disorders. * End-stage renal disease that requires chronic dialysis. * Concurrent haemorrhagic or obstructive shock. * Increased risk of fluid intolerance: * Echocardiographic evidence of moderate or severe left ventricular systolic dysfunction. * Echocardiographic evidence of moderate or severe right ventricular systolic dysfunction. * Hypoxemia index \< 200 mmHg or sonographic evidence of bilateral B or C profile. * Abdominal compartment syndrome. * Post-cardiac arrest.