Effect of Vitamin C on mortality of critically ill patients with severe pneumonia in intensive care unit: a preliminary study.

BACKGROUND: Critically ill patients frequently suffer from vitamin C deficiency. Previous studies showed that high doses of vitamin C administration had conflicting results on clinical outcomes in patients with severe sepsis, burns, and trauma. Because of the high incidence and morbidity/mortality with severe pneumonia, we aimed to investigate the effect of administration of high dose vitamin C in critically ill patients with severe pneumonia. METHODS: Eighty critically ill patients with pneumonia were enrolled in this randomized double-blinded clinical trial. Patients with a CURB-65 score > 3, one major criterion, or ≥ 3 minor criteria were considered as severe pneumonia. Patients were randomly assigned to intervention or placebo groups receiving standard treatment plus 60 mg/kg/day vitamin C as a continuous infusion or normal saline in the same volume correspondingly for 96 h. Serum levels of vitamin C were noted at baseline and 48 h after vitamin C administration. Duration of mechanical ventilation, ICU length of stay, PaO2/FiO2, and mortality rate were noted for all patients till the 28th day. Any complications related to the vitamin C administration were recorded. RESULTS: Duration of mechanical ventilation and vasopressor use were significantly lower in the intervention group (p: < 0.001 and 0.003, respectively). Baseline levels of vitamin C in both groups did not have a significant difference but its levels increased in the intervention group and decreased in the control group during the study period. Mortality rate insignificantly decreased in the intervention group (p = 0.17). Three patients showed hypotension and tachycardia during the administration of vitamin C which was self-limited with decreasing the dose of vitamin C. Our results showed that the intravenous administration of a relatively high dose of vitamin C to critically ill patients with severe pneumonia was safe and could decrease the inflammation, duration of mechanical ventilation, and vasopressor use without any significant effect on mortality. TRIAL REGISTRATION: IRCT registration number: IRCT20190312043030N1, Registration date: 2019-08-26, Seied Hadi Saghaleini.

Daily parenteral selenium therapy in critically ill patients: An updated systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIM: Patients hospitalized at the intensive care unit (ICU) are more prone to oxidative stress. Antioxidants such as selenium (Se) may have beneficial effects on outcomes in these patients. Studies and systematic reviews in this field have inconclusive results. METHODS: An updated systematic search was done to find clinical trials published in PubMed, Cochrane's library, ISI web of Science, Scopus, and Ovid databases from January 1980 up to April 2020, to assess the effects of daily Se supplementation on patient's survival, hospital and ICU stay, duration of mechanical ventilation, infection, acute renal failure (ARF) occurrence and serum creatinine levels. RESULTS: From 1394 papers found in the first step of the search, after deleting duplicate findings, 24 studies were included in this meta-analysis. Results of the pooled random-effect size analysis of 24 trials showed no remarkable effect of daily parenteral Se administration on patient's hospital and ICU stay, duration of mechanical ventilation, infectious complications, ARF, survival and serum creatinine levels (p > 0.05). The subgroup analysis showed that daily parenteral Se administration (in doses higher than 1000 µg/d) increased the length of ICU stay by 4.48-folds (95%CI: -0.5, 9.46, p = 0.07). Parenteral Se supplementation at the first and following dose of ≤1000 µg reduced the number of ARF at the hospitalized patients by 76% and 45%, respectively (p = 0.02, and p = 0.05). CONCLUSIONS: High doses of Se increases days of ICU stay, but low doses decreases the number of ARF occurrence in ICU patients. More trials are needed to assess its effect on ARF occurrence.

The Effect of Intravenous Selenium on Oxidative Stress in Critically Ill Patients with Acute Respiratory Distress Syndrome.

OBJECTIVE: To modulate the inflammatory response in respiratory distress syndrome (ARDS) with selenium. BACKGROUND: Selenium replenishes the glutathione peroxidase proteins that are the first line of defense for an oxidative injury to the lungs. METHODS: Forty patients with ARDS were randomized into two groups: the SEL+ group being administered sodium selenite and the SEL- group receiving normal saline for 10 days. Blood samples were taken on Day-0, DAY-7, and Day-14 for assessment of IL-1 beta, IL-6, C-reactive protein, GPx-3, and selenium. Ferric reducing antioxidant power (FRAP) was measured in the bronchial wash fluids. Pearson correlation and repeated measure analysis were performed to examine the effects of selenium on the inflammatory markers. RESULTS: Sodium selenite replenished selenium levels in the SEL+ group. Selenium concentrations were linearly correlated to serum concentrations of GPx3 (R value: 0.631; P < 0.001), and FRAP (R value: -0.785; P < 0.001). Serum concentrations of both IL 1-beta (R value: -0.624; P < 0.001) and IL-6 (R value: -0.642; P < 0.001) were inversely correlated to the serum concentrations of selenium. There was a meaningful difference between two groups in airway resistance and pulmonary compliance changes (P values 0.008 and 0.028, respectively). CONCLUSION: Selenium restored the antioxidant capacity of the lungs, moderated the inflammatory responses, and meaningfully improved the respiratory mechanics. Despite these changes, it had no effect on the overall survival, the duration of mechanical ventilation, and ICU stay. Selenium can be used safely; however, more trials are essential to examine its clinical effectiveness.