Using Fluorescence Angiography to Detect Occult Shock

Inclusion Criteria: * Sepsis arm inclusion criteria: * Diagnosis of severe sepsis and septic shock. * Sepsis is defined as at least two of the following signs and symptoms (SIRS) that are both present and new to the patient and suspicion of new infection: * Hyperthermia \>38.3°C or Hypothermia \<36°C * Tachycardia \>90 bpm * Tachypnea \>20 bpm * Leukocytosis (\>12,000 μL-1) or Leukopenia (\<4,000 μL-1) or \>10% bands. * Hyperglycemia (\>120 mg/dl) in the absence of diabetes. * Severe sepsis includes SIRS and at least one of the following signs of hypoperfusion or organ dysfunction that is new and not explained by other known etiology of organ dysfunction: * Hypotension (\<90/60 or MAP \<65) * Lactate \>2 * Areas of mottled skin or capillary refill \>3 seconds * Creatinine \>2.0 mg/dl * Disseminated intravascular coagulation (DIC), Platelet count \<100,000 * Acute renal failure or urine output \<0.5 ml/kg/hr for at least 2 hours * Hepatic dysfunction as evidenced by: * Bilirubin \>2 or INR \>1.5 * Cardiac dysfunction * Acute lung injury or ARDS * Control arm inclusion criteria: * Do not have diagnosis of sepsis, severe sepsis, or septic shock * Are not on vasopressors * Are normo-thermic Exclusion Criteria: * Sepsis arm exclusion criteria: * Pregnant * Iodide allergy * Burns * Control arm exclusion criteria: * Pregnant * Iodide allergy * Burns * Individuals for whom a surrogate decision maker is not available, or is not able to consent to the study.