The effect of vitamin C on pulmonary oedema in patients with severe preeclampsia: A single-centre, randomised, placebo-controlled, double-blind trial.

OBJECTIVE: To determine whether vitamin C in the first three days postpartum reduces pulmonary oedema (PE) assessed by lung ultrasound in patients with severe preeclampsia.

DESIGN: Randomised, placebo-controlled, double-blind trial.

SETTING: Tertiary perinatal centre.

POPULATION: Consecutively admitted patients with singleton pregnancies complicated by severe preeclampsia.

METHODS: Thirty-four patients received vitamin C (1.5 g/6 h) (n = 17) or placebo (n = 17) at days 1, 2, and 3 postdelivery. Mann-Whitney-U test was used to compare vitamin C vs placebo groups. A p ≤ 0.05 was considered statistically significant.

MAIN OUTCOME MEASURES: Lung ultrasound was performed once daily in the first three days following delivery. Echo Comet Score (ECS) on day 1 postdelivery was the primary outcome studied and was obtained using the 28-rib interspaces technique. ECS on days 2 and 3 postdelivery were secondary outcomes.

RESULTS: There was no significant difference in ECS on day 1 (median 23 (inter-quartile range (IQR) 21-61) vs 18 (IQR 8-35); p = 0.31). All ultrasound examinations on day 1 were performed within six hours from delivery. On days 2 and 3, ECS was significantly lower in vitamin C group compared to placebo (8 (IQR 3-14) vs 35 (IQR 15-78); p = 0.03 and 5 (IQR 3-10) vs 18 (IQR 18-44); p = 0.04, respectively).

CONCLUSION: A single dose of intravenous vitamin C did not reduce PE in postpartum patients with severe preeclampsia on day 1 after delivery. Repeated doses, however, seem to have a delayed effect with a reduction in PE detected on ultrasound on days 2 and 3 following delivery.

TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov: ID NCT03451266 (https://clinicaltrials.gov/ct2/show/NCT03451266?term=NCT03451266&draw=2&rank=1).