Effect of High Dose Intravenous Vitamin C in Severe Pneumonia (VICSEP)

Inclusion Criteria: Patients who are aged 18 and above Patients who are diagnosed with severe pneumonia Patients who are mechanically ventilated Exclusion Criteria: Known allergy to Vitamin C Pregnancy Known history of ongoing concomitant infection Participation in another clinical trial and/or receipt of investigational drugs within 4 weeks prior to enrollment Moribund patient with multiorgan failure to the judgement of the treating physician, who is not expected to survive 24 hours Patient who requires home oxygen therapy or mechanical ventilation, including tracheostomy or non-invasive ventilation, except for CPAP/BIPAP for sleep-disordered breathing Known history of previous or current diagnosis of renal stones Known diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency Known diagnosis of hemochromatosis Known diagnosis of poorly controlled chronic pulmonary disease, including: Chronic obstructive pulmonary disease with oxygen therapy Chronic restrictive pulmonary disease with oxygen therapy Bronchial asthma on Step 5 of treatment ladder as shown in Pocket Guide for Asthma Management and Prevention Lung cancer in Stage IV of disease Known diagnosis of heart failure on anti-failure treatment or requiring mechanical hemodynamic support (e.g. LVAD), with recent hospitalization within 3 months (90 days) from the date of current admission. Immunocompromised state Known diagnosis of malignancy and ongoing chemotherapy or radiotherapy as there is evidence that antioxidant supplement before and during treatment was associated with an increased hazard of recurrence Known diagnosis of malignancy who had completed chemotherapy or radiotherapy with absolute neutrophil count ≤100 cells/mm3 Known diagnosis of Stage 4 and above chronic kidney disease (GFR <30 ml/min/1.73m2) and end-stage renal disease on regular dialysis (including peritoneal dialysis or hemodialysis) Known history of renal transplantation Absence of family members or next of kin for informed consent