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2.
Free Radic Biol Med ; 160: 13-18, 2020 11 20.
Article in English | MEDLINE | ID: mdl-32768569

ABSTRACT

BACKGROUND: Supplemental oxygen is delivered to critically ill patients who require mechanical ventilation. Oxidative stress is a potential complication of oxygen therapy, resulting in damage to essential biomolecules such as proteins, lipids, and nucleic acids. Whether plasma levels of oxidative stress biomarkers vary based on how liberally oxygen therapy is applied during mechanical ventilation is unknown. METHODS: We carried out an oxidative stress substudy nested within a large multi-centre randomized controlled trial in which critically ill adults were randomized to receive either conservative oxygen therapy or standard oxygen therapy. Blood samples were collected at enrolment, and daily thereafter for up to three days. The antioxidant ascorbate (vitamin C) was assessed using HPLC with electrochemical detection and protein oxidation using a sensitive protein carbonyl ELISA. We also assessed whether critically ill patients with different disease states exhibited varying levels of oxidative stress biomarkers. RESULTS: A total of 125 patients were included. Mean ascorbate concentrations decreased over time (from 25 ± 9 µmol/L to 14 ± 2 µmol/L, p < 0.001), however, there was no significant difference between the conservative oxygen group and standard care (p = 0.2), despite a significantly lower partial pressure of oxygen (PaO2) in the conservative oxygen group (p = 0.03). Protein carbonyl concentrations increased over time (from 208 ± 30 µmol/L to 249 ± 29 µmol/L; p = 0.016), however, there was no significant difference between the conservative and standard oxygen groups (p = 0.3). Patients with sepsis had significantly higher protein carbonyl concentrations than the other critically ill patients (293 ± 92 µmol/L vs 184 ± 24 µmol/L, p = 0.03). Within the septic subgroup, there were no significant differences in protein carbonyl concentrations between the two interventions (p = 0.4). CONCLUSIONS: Conservative oxygen therapy does not alter systemic markers of oxidative stress in critically ill ventilated patients compared with standard oxygen therapy. Patients with sepsis exhibited elevated protein carbonyls compared with the other critically ill patients implying increased oxidative stress in this patient subgroup.


Subject(s)
Critical Illness , Oxygen Inhalation Therapy , Oxygen , Adult , Biomarkers , Humans , Oxidative Stress , Respiration, Artificial
3.
JAMA ; 323(5): 423-431, 2020 02 04.
Article in English | MEDLINE | ID: mdl-31950979

ABSTRACT

Importance: It is unclear whether vitamin C, hydrocortisone, and thiamine are more effective than hydrocortisone alone in expediting resolution of septic shock. Objective: To determine whether the combination of vitamin C, hydrocortisone, and thiamine, compared with hydrocortisone alone, improves the duration of time alive and free of vasopressor administration in patients with septic shock. Design, Setting, and Participants: Multicenter, open-label, randomized clinical trial conducted in 10 intensive care units in Australia, New Zealand, and Brazil that recruited 216 patients fulfilling the Sepsis-3 definition of septic shock. The first patient was enrolled on May 8, 2018, and the last on July 9, 2019. The final date of follow-up was October 6, 2019. Interventions: Patients were randomized to the intervention group (n = 109), consisting of intravenous vitamin C (1.5 g every 6 hours), hydrocortisone (50 mg every 6 hours), and thiamine (200 mg every 12 hours), or to the control group (n = 107), consisting of intravenous hydrocortisone (50 mg every 6 hours) alone until shock resolution or up to 10 days. Main Outcomes and Measures: The primary trial outcome was duration of time alive and free of vasopressor administration up to day 7. Ten secondary outcomes were prespecified, including 90-day mortality. Results: Among 216 patients who were randomized, 211 provided consent and completed the primary outcome measurement (mean age, 61.7 years [SD, 15.0]; 133 men [63%]). Time alive and vasopressor free up to day 7 was 122.1 hours (interquartile range [IQR], 76.3-145.4 hours) in the intervention group and 124.6 hours (IQR, 82.1-147.0 hours) in the control group; the median of all paired differences was -0.6 hours (95% CI, -8.3 to 7.2 hours; P = .83). Of 10 prespecified secondary outcomes, 9 showed no statistically significant difference. Ninety-day mortality was 30/105 (28.6%) in the intervention group and 25/102 (24.5%) in the control group (hazard ratio, 1.18; 95% CI, 0.69-2.00). No serious adverse events were reported. Conclusions and Relevance: In patients with septic shock, treatment with intravenous vitamin C, hydrocortisone, and thiamine, compared with intravenous hydrocortisone alone, did not significantly improve the duration of time alive and free of vasopressor administration over 7 days. The finding suggests that treatment with intravenous vitamin C, hydrocortisone, and thiamine does not lead to a more rapid resolution of septic shock compared with intravenous hydrocortisone alone. Trial Registration: ClinicalTrials.gov Identifier: NCT03333278.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Ascorbic Acid/therapeutic use , Hydrocortisone/therapeutic use , Shock, Septic/drug therapy , Thiamine/therapeutic use , Vitamins/therapeutic use , Administration, Intravenous , Aged , Anti-Inflammatory Agents/administration & dosage , Ascorbic Acid/administration & dosage , Drug Therapy, Combination , Female , Hospital Mortality , Humans , Hydrocortisone/administration & dosage , Male , Middle Aged , Shock, Septic/mortality , Vasoconstrictor Agents/therapeutic use , Vitamins/administration & dosage
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