Subjects will be randomized 1:1 to receive either high dose IV Vitamin C (12g/day) or placebo, every 6 hourly, until successful extubation (minimum 16 doses, maximum 40 doses). Placebo will be the equivalent volume of dextrose 5% given intravenously. Active drug or placebo will be prepared in a sterile method by designated personnel at each site. Active drug or placebo will be prepared in a 50cc syringe and infusion tubing attached, where both are coloured and UV-protected. The recruitment period is expected to be 24 months. Phone call follow-up will be conducted at day 60 (+7 days) post-randomization to review subjects' activities of daily living. All data will be entered electronically into REDCap.~All randomized subjects will be included in the intention-to-treat analysis (ITT) dataset for primary and secondary efficacy endpoints analyses. Safety analysis will be conducted for all subjects who received at least one dose of study drug. There are no interim analyses planned in this trial. At least one safety review will be conducted at 50% target recruitment.
This trial is a multicenter, randomized, double-blind, two-arm, parallel-group, placebo-controlled trial to investigate the effect of high dose intravenous (IV) Vitamin C as an adjunct to the standard of care for patients with severe pneumonia versus placebo in ICU.