Synthetic Angiotensin II/Giapreza in Pediatric Patients With Refractory Hypotension

The goal of this clinical trial is to determine the safety and efficacy of Angiotensin-II in the treatment of pediatric patients in fluid refractory vasodilatory shock. The main questions it aims to answer are: * To evaluate the change in blood pressure or reduction of vasoactive requirements (norepinephrine equivalent dosing) after initiating Angiotensin II * To establish the safety and tolerability of Angiotensin-II in pediatric patients Participants will receive Angiotensin-II in addition to standard of care therapy for vasodilatory shock. * The study team will then monitor the patient's vital signs, blood work, and for any potential side effects from the drug. * An ultrasound will be performed to look at blood flow through the kidney in the setting of vasodilatory shock. * A follow up phone call to check in with the patient will be performed 28 days after enrollment.

Inclusion Criteria: * Pediatric patients less than 18 years of age who have received at least 40 mL/kg of crystalloid or colloid equivalent fluid resuscitation for vasodilatory shock * Titration of standard of care vasoactive medications for a minimum of 2 hours with persistent refractory hypotension for age, and who require a total sum NE equivalent dose of \> 0.1 μg/kg/min for a minimum of 1 hours and a maximum of 24 hours prior to initiation of Angiotensin-II. * Indwelling arterial and central venous lines. * Parent or legal guardian is willing and able to provide informed consent and assist the patient in complying with all protocol requirements. Exclusion Criteria: * Standing DNR/DNI order * Alternative shock diagnosis i.e. cardiogenic shock or post cardiac surgery * Cannulated to extracorporeal membrane oxygenation * Pre-existing condition confounding outcome determination such as terminal illness * Patients diagnosed with acute occlusive coronary syndrome requiring pending intervention. * Patients who have a history of asthma or are currently experiencing bronchospasm requiring the use of inhaled bronchodilators and who are not mechanically ventilated. * Patients with acute mesenteric ischemia or a history of mesenteric ischemia. * Patients with active bleeding AND an anticipated need of multiple transfusions (within 48 hours of Screening). * Patients with active bleeding, hemoglobin \< 7 g/dL, or any other condition that would contraindicate serial blood sampling. * Patients requiring more than 5 mg/kg daily of hydrocortisone or equivalent glucocorticoid medication as a standing dose. * Patients with an expected lifespan of \< 12 hours or withdrawal of life support within 24 hours of screening. * Patients currently using an angiotensin converting enzyme inhibitor or angiotensin receptor blocker. * Patients with a known allergy to mannitol. * Patients who are currently participating in another investigational clinical trial. * Patients of childbearing potential who are known to be pregnant at the time of screening. * Prisoners * Patient's with Raynaud phenomenon, systemic sclerosis, or vasospastic disease.