Preclinical Critical Care Unit, Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC, Australia.
Centre for Integrated Critical Care, Department of Medicine and Radiology, University of Melbourne, VIC, Australia.
Crit Care Med. 2021 Feb 1;49(2):e179-e190. doi: 10.1097/CCM.0000000000004770.
Oxidative stress appears to initiate organ failure in sepsis, justifying treatment with antioxidants such as vitamin C at megadoses. We have therefore investigated the safety and efficacy of megadose sodium ascorbate in sepsis.
Interventional study.
Research Institute.
Adult Merino ewes.
Sheep were instrumented with pulmonary and renal artery flow-probes, and laser-Doppler and oxygen-sensing probes in the kidney. Conscious sheep received an infusion of live Escherichia coli for 31 hours. At 23.5 hours of sepsis, sheep received fluid resuscitation (30 mL/kg, Hartmann solution) and were randomized to IV sodium ascorbate (0.5 g/kg over 0.5 hr + 0.5 g/kg/hr for 6.5 hr; n = 5) or vehicle (n = 5). Norepinephrine was titrated to restore mean arterial pressure to baseline values (~80 mm Hg).
Sepsis-induced fever (41.4 ± 0.2°C; mean ± se), tachycardia (141 ± 2 beats/min), and a marked deterioration in clinical condition in all cases. Mean arterial pressure (86 ± 1 to 67 ± 2 mm Hg), arterial Po2 (102.1 ± 3.3 to 80.5 ± 3.4 mm Hg), and renal medullary tissue Po2 (41 ± 5 to 24 ± 2 mm Hg) decreased, and plasma creatinine doubled (71 ± 2 to 144 ± 15 µmol/L) (all p < 0.01). Direct observation indicated that in all animals, sodium ascorbate dramatically improved the clinical state, from malaise and lethargy to a responsive, alert state within 3 hours. Body temperature (39.3 ± 0.3°C), heart rate (99.7 ± 3 beats/min), and plasma creatinine (32.6 ± 5.8 µmol/L) all decreased. Arterial (96.5 ± 2.5 mm Hg) and renal medullary Po2 (48 ± 5 mm Hg) increased. The norepinephrine dose was decreased, to zero in four of five sheep, whereas mean arterial pressure increased (to 83 ± 2 mm Hg). We confirmed these physiologic findings in a coronavirus disease 2019 patient with shock by compassionate use of 60 g of sodium ascorbate over 7 hours.
IV megadose sodium ascorbate reversed the pathophysiological and behavioral responses to Gram-negative sepsis without adverse side effects. Clinical studies are required to determine if such a dose has similar benefits in septic patients.
氧化应激似乎是脓毒症中器官衰竭的起始因素,这证明了使用大剂量维生素 C 等抗氧化剂进行治疗是合理的。因此,我们研究了大剂量注射用抗坏血酸钠在脓毒症中的安全性和疗效。
干预性研究。
研究所。
成年美利奴羊。
羊被安置了肺动脉和肾动脉流量探头,以及肾脏的激光多普勒和氧敏探头。清醒的羊接受了 live Escherichia coli 的输注,持续 31 小时。在脓毒症的 23.5 小时,羊接受了液体复苏(30mL/kg,Hartmann 溶液),并随机分为 IV 注射用抗坏血酸钠(0.5g/kg,0.5 小时内输注,然后 0.5g/kg/hr 输注 6.5 小时;n = 5)或载体(n = 5)。去甲肾上腺素被滴定以将平均动脉压恢复到基线值(~80mmHg)。
脓毒症引起的发热(41.4 ± 0.2°C;均值 ± se)、心动过速(141 ± 2 次/分钟)和所有病例临床状况的显著恶化。平均动脉压(86 ± 1 至 67 ± 2mmHg)、动脉 Po2(102.1 ± 3.3 至 80.5 ± 3.4mmHg)和肾髓质组织 Po2(41 ± 5 至 24 ± 2mmHg)下降,血浆肌酐增加一倍(71 ± 2 至 144 ± 15μmol/L)(均 p < 0.01)。直接观察表明,在所有动物中,抗坏血酸钠在 3 小时内显著改善了临床状态,从不适和昏睡转变为反应灵敏、警觉的状态。体温(39.3 ± 0.3°C)、心率(99.7 ± 3 次/分钟)和血浆肌酐(32.6 ± 5.8μmol/L)均下降。动脉(96.5 ± 2.5mmHg)和肾髓质 Po2(48 ± 5mmHg)增加。去甲肾上腺素剂量减少,五分之四的羊减少到零,而平均动脉压升高(至 83 ± 2mmHg)。我们通过同情使用 60g 注射用抗坏血酸钠,在一名患有休克的 2019 年冠状病毒病患者中证实了这些生理发现。
IV 大剂量注射用抗坏血酸钠逆转了革兰氏阴性脓毒症的病理生理和行为反应,没有不良反应。需要进行临床研究以确定这种剂量是否对脓毒症患者有类似的益处。