Table 1 A summary of recent meta-analysis of vitamin C administration in critical care patients

Putzu et al. [3]

Crit Care Med

The effect of vitamin C on clinical outcome in critically ill patients: A systematic review with meta-analysis of randomised controlled trials

P—adult critically ill patients

I—vitC (any regimen)

C—placebo or no therapy

O—mortality, acute kidney injury, supraventricular arrhythmia, ventricular arrhythmia, stroke, ICU LOS, hospital LOS

44 RCTs:

16 in ICU setting (n = 2857)

28 in cardiac surgery (n = 3598)

Mixed ICU vs burns vs sepsis/septic shock vs acute pancreatitis

VitC alone vs enteral vitC vs IV vitC vs IV vitC > 5 g

ICU patients:

X mortality

X acute kidney injury

X ICU or hospital LOS

Cardiac surgery:

↓ postoperative atrial fibrillation

↓ ICU and hospital LOS

Wang et al. [4]

Ann Intensive Care

Effects of different ascorbic acid doses on the mortality of critically ill patients: a meta-analysis

P—critically ill patients

I—IV vitC (including co-administration of antioxidants)

C—placebo or no intervention

O—mortality, resuscitation fluid requirement, urine output, acute kidney injury, vasopressor requirement, duration of mechanical ventilation, ICU and/or hospital LOS

12 RCT, quasi-RCT, observational (n = 1210)

Low dose vs medium dose vs high dose

Burn vs sepsis vs others

↓ mortality (doses of 3–10 g/day)

X morality (< 3 g/day or ≥ 10 g/day)

↓ duration of vasopressor support

↓ duration of mechanical ventilation

X acute kidney injury

X ICU or hospital LOS

X fluid requirement

X urine output

Hemila and Chalker [5]

Vitamin C can shorten the length of stay in the ICU: A meta-analysis

P—ICU patients

I—vitC

C—placebo or none

O—ICU LOS, duration of mechanical ventilation

18 controlled trials (n = 2004)

including 13 cardiac surgery

IV vs oral

1–2 days ICU vs 3–5 days ICU

> 24 h ventilation vs < 24 h ventilation

↓ ICU LOS

↓ duration of mechanical ventilation

Langlois et al. [6]

JPEN

Vitamin C supplementation in the critically ill: A systematic review and meta-analysis

P—ICU patients

I—vitC (enteral or parenteral)

C—placebo or none

O—mortality, incident infections, ICU LOS, hospital LOS, duration of mechanical ventilation

11 RCTs

9 RCTs with mortality (n = 1322)

Low dose vs high dose

Combined therapy vs monotherapy

Oral/enteral vs parenteral

Non-septic vs septic

Higher-quality trials vs low-quality trials

X mortality

↓ (trend) mortality (IV high dose vitC monotherapy)

X infections

X ICU or hospital LOS

X duration of mechanical ventilation

Zhang and Jativa [7]

SAGE Open Med

Vitamin C supplementation in the critically ill: A systematic review and meta-analysis

P—critically ill adult patients

I—IV vitC

C—placebo or no intervention

O—mortality, duration of mechanical ventilation, duration of vasopressor support, fluid requirements, urine output

4 RCTs and 1 retrospective (n = 142)

X mortality

↓ need for vasopressor support

↓ duration of mechanical ventilation

↓ (trend) fluid requirements

↑ (trend) urine output

Li

Crit Care [1]

Evidence is stronger than you think: a meta-analysis of vitamin C use in patients with sepsis

P—patients with sepsis

I—IV vitC

C—placebo or none

O—mortality, ICU LOS, vasopressor duration

2 RCTs and 1 before-after

↓ mortality

X ICU LOS

↓ vasopressor duration

Lin et al. [8]

Open J Intern Med

Adjuvant administration of vitamin C improves mortality of patients with sepsis and septic shock: A systems review and meta-analysis

P—patients with septic shock and severe sepsis

I—vitC

C—placebo

O—mortality

4 RCTs and 2 retrospective studies (n = 109)

RCT vs retrospective

High dose vs low dose

X mortality

↓ mortality (doses of > 50 mg/kg/day)

X ICU LOS