1. no consent/inability to obtain consent 2. patient, surrogate, or physician not committed to full support 3. malignant or other irreversible condition and estimated 28-day mortality ≥ 50% 4. moribund patient not expected to survive 48 hours (as defined by primary medical team) from start of study infusion 5. end-stage liver disease as defined by child-pugh score \> 9 6. currently enrolled in, or participated in another study of an investigational compound within the last 30 days 7. pregnant female, or female who is breast feeding 8. allergy to l-citrulline or arginine or any citrulline- or arginine-containing product 9. patient not otherwise suitable for the study in the opinion of any of the investigators 10. requirement for intubation and invasive mechanical ventilation before study enrollment

1. no consent/inability to obtain consent 2. patient, surrogate, or physician not committed to full support 3. malignant or other irreversible condition and estimated 28-day mortality ≥ 50% 4. moribund patient not expected to survive 48 hours (as defined by primary medical team) from start of study infusion 5. end-stage liver disease as defined by child-pugh score \> 9 6. currently enrolled in, or participated in another study of an investigational compound within the last 30 days 7. pregnant female, or female who is breast feeding 8. allergy to l-citrulline or arginine or any citrulline- or arginine-containing product 9. patient not otherwise suitable for the study in the opinion of any of the investigators 10. requirement for intubation and invasive mechanical ventilation before study enrollment

no consent/inability to obtain consent patient, surrogate, or physician not committed to full support malignant or other irreversible condition and estimated 28-day mortality ≥ 50% moribund patient not expected to survive 48 hours (as defined by primary medical team) from start of study infusion end-stage liver disease as defined by child-pugh score > 9 currently enrolled in, or participated in another study of an investigational compound within the last 30 days pregnant female, or female who is breast feeding allergy to l-citrulline or arginine or any citrulline- or arginine-containing product patient not otherwise suitable for the study in the opinion of any of the investigators requirement for intubation and invasive mechanical ventilation before study enrollment

no consent/inability to obtain consent patient, surrogate, or physician not committed to full support malignant or other irreversible condition and estimated 28-day mortality ≥ 50% moribund patient not expected to survive 48 hours (as defined by primary medical team) from start of study infusion end-stage liver disease as defined by child-pugh score > 9 currently enrolled in, or participated in another study of an investigational compound within the last 30 days pregnant female, or female who is breast feeding allergy to l-citrulline or arginine or any citrulline- or arginine-containing product patient not otherwise suitable for the study in the opinion of any of the investigators requirement for intubation and invasive mechanical ventilation before study enrollment

1. no consent/inability to obtain consent 2. patient, surrogate, or physician not committed to full support 3. malignant or other irreversible condition and estimated 28-day mortality ≥ 50% 4. moribund patient not expected to survive 48 hours (as defined by primary medical team) from start of study infusion 5. end-stage liver disease as defined by child-pugh score > 9 6. currently enrolled in, or participated in another study of an investigational compound within the last 30 days 7. pregnant female, or female who is breast feeding 8. allergy to l-citrulline or arginine or any citrulline- or arginine-containing product 9. patient not otherwise suitable for the study in the opinion of any of the investigators 10. requirement for intubation and invasive mechanical ventilation before study enrollment

1. no consent/inability to obtain consent 2. patient, surrogate, or physician not committed to full support 3. malignant or other irreversible condition and estimated 28-day mortality ≥ 50% 4. moribund patient not expected to survive 48 hours (as defined by primary medical team) from start of study infusion 5. end-stage liver disease as defined by child-pugh score > 9 6. currently enrolled in, or participated in another study of an investigational compound within the last 30 days 7. pregnant female, or female who is breast feeding 8. allergy to l-citrulline or arginine or any citrulline- or arginine-containing product 9. patient not otherwise suitable for the study in the opinion of any of the investigators 10. requirement for intubation and invasive mechanical ventilation before study enrollment