Treatment of ARDS With Instilled T3

Inclusion Criteria: Study population is critically ill patients requiring mechanical ventilatory support for ARDS in an intensive care unit. * Adults (≥18 years of age). * Male or female (non-pregnant). * Clinical diagnosis of ARDS (all are required): 1. Onset: \<= 7 days. 2. Chest x-ray: Bilateral Patchy Opacities, Infiltrates. 3. Mechanical Vent Support: PEEP or CPAP Support \>= 5 cm H2O. 4. Pulmonary Edema: Not fully explained by cardiogenic etiology. 5. Hypoxia: PaO2/FIO2 Ratio \<300, or O2Sat/FIO2 Ratio \<315. * On mechanical ventilatory support. * Capable of giving informed consent directly or from the subject's legally authorized representative (LAR) as determined by the site Principal Investigator and/or Sub- Investigators. Exclusion Criteria: Patients with any of the following conditions will be excluded from this trial: * Inadequate medical history for determining inclusion/exclusion criteria, as determined by the Principal Investigator and/or Sub- Investigators. * Unlikely to complete the protocol with clinic follow-up after discharge, as determined by the Principal Investigator and/or Sub- Investigators or hospice status. * Prior history of thyroid cancer or hyperthyroidism, per thorough patient/family interviews, review of past medical history, medication list, laboratory test. * Prior history of cardiovascular disease defined as: 1. Hypertensive crisis in the past 3 months (systolic \>200, or diastolic \>120 mmHg), 2. Sustained ventricular arrhythmia in the past 3 months (duration \>30 seconds) 3. Coronary artery disease (documented \>=70% occlusion untreated in any coronary vessel), as per the 2021 ACC/AHA/SCAI Guidelines for Coronary Artery Revascularization. 4. Cardiac-related angina pectoris (\>=2 episodes in the past 3 months) 5. Myocardial infarction with ischemia on ECG (i.e.,new ST- elevation/depression of \>1mm in contiguous leads). 6. Peripheral vascular disease (documented \>=70% occlusion untreated in any peripheral vessel), as per the 2018 ACC/AHA/SCAI/SIR/SVM Guidelines for Appropriate Use Criteria for Peripheral Artery Intervention. 7. Decompensated or symptomatic heart failure (i.e., hospitalized for CHF exacerbation, or a change in CHF medications within two weeks prior) * Currently pregnant or breastfeeding. * Known allergy to study drug.