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Impact of Vitamin C on Biomarkers of Neurologic Injury in Survivors of Cardiac Arrest

Phase 2
Conditions
Neurological Injury
Biomarkers
Heart Arrest, Out-Of-Hospital
Oxidative Stress
Interventions
Drug: Placebo
Registration Number
NCT04563000
Lead Sponsor
University Medical Centre Maribor
Brief Summary

Out-of-hospital cardiac arrest (OHCA) is one of the leading cause of death in the world. In Slovenia approximately 25% of resuscitated patients survives to discharge from hospitals, usually with poorer functional status.

One of key pathophysiological process responsible for poorer functional status is global hypoxic-ischemic injury, which is two-stage. Primary stage occurs immediately after cardiac arrest due to cessation of blood flow. With return of spontaneous circulation a secondary injury occurs, of which the leading process is an imbalance between oxygen delivery and consumption. Reperfusion exposes ischemic tissue to oxygen, resulting in the formation of large amounts of highly reactive oxygen species (ROS) within minutes. ROS lead to oxidative stress, which causes extensive damage to cell structures and leads to cell death. Consequently, necrosis and apoptosis are responsible for organ dysfunction and functional outcome of these patients.

Such injury of neural tissue causes brain damage, which is ultimately responsible for poor neurological and thus functional outcome of OHCA survivors. The extent of brain damage can be determined in several ways: clinically by assessing quantitative and qualitative consciousness and the presence of involuntary movements in an unconscious patient, by assessing activity on electroencephalographic record, by imaging of the brain with computed tomography and magnetic resonance imaging, as well as by assessing levels of biological markers of brain injury. Of the latter, the S-100b protein and neuron-specific enolase have been shown to be suitable for such assessment.

Oxidative stress is counteracted by the body with endogenous antioxidants that balance excess free radicals and stabilize cellular function. Vitamin C (ascorbic acid) is the body's main antioxidant and is primarily consumed during oxidative stress. Large amounts of ROS rapidly depletes the body's vitamin C stores.

Humans cannot synthesise vitamin C and enteral uptake of vitamin C is limited by transporter saturation. On the other hand, parenteral (venous) dosing of vitamin C can achieve concentrations of vitamin C above physiological and thus produce a stronger antioxidant effect. The beneficial effect of parenteral dosing of vitamin C has been establish in several preclinical and clinical studies in patients with ischemic stroke and cardiac arrest.

The investigators hypothesize that there is a similarly beneficial effect of vitamin C in survivors of OHCA.

Detailed Description

Not available

Recruitment & Eligibility

Status
UNKNOWN
Sex
All
Target Recruitment
150
Inclusion Criteria
  • comatose survivors of out-of-hospital arrest
Exclusion Criteria
  • patients with trauma, asphyxia, drowning or electrocution as a cause of cardiac arrest
  • history of oxalate nephropathy or nephrolithiasis, glucose-6-phosphate dehydrogenase deficiency, and hemochromatosis
  • pregnancy

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
PlaceboPlaceboGroup of patients that will receive placebo (0,9 % solution of sodium chloride 100 ml every 12 hours for 4 days intravenously).
Vitamin CVitamin CGroup of patients that will receive vitamin C (ascorbic acid 1,5 g mixed with 0,9 % solution of sodium chloride 100 ml every 12 hours for 4 days intravenously).
Primary Outcome Measures
NameTimeMethod
Biomarkers of neurological injury5th day

Serum levels of protein S-100b and neuron-specific enolase.

Secondary Outcome Measures
NameTimeMethod
Electroencephalography (EEG)3rd-10th day

Unconscious survivors will have first EEG on the 3rd day, if still unconscious, second imaging around the 10th day. EEG results will be descriptive (normal or pathological with background suppression with or without periods of bursts, with or without response to external stimulus and similar patterns). Second EEG will be compared to the first.

Evaluation of GCSfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Level of consciousness will be determined daily with Glasgow Coma Scale (GCS).

Evaluation of heart failurefrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Clinical evaluation of heart failure according to Killip-Kimball classification will be performed (worst result).

Serum Brain natriuretic peptidefrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Serum brain natriuretic peptide levels will be determined (on admission, minimal, maximal).

Mechanical ventilationfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Days and hours of mechanical ventilation will be noted.

Cerebral Performance Categoryfrom admission till discharge from ICU or death (whatever comes first)

Cerebral Performance Category (CPC) at discharge will be recorded.

Brain imaging (CT and MRI)3rd-10th day

Unconscious survivors will have first brain imaging on the 3rd day, if still unconscious, second imaging around the 10th day. Imaging results will be descriptive (normal or pathological with signs of global ischemic injury: generalised edema, reduced grey and white matter differentiation, obliteration of the sulci). Second image will be compared to the first.

Evaluation of pupilsfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Pupils size, reactivity and symmetry on admission and during hospitalisation will be observed daily.

Evaluation of involuntary movementsfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

The presence of involuntary movements will be observed daily.

Evaluation of FOURfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Level of consciousness will be determined daily with Full Outline of UnResponsiveness (FOUR) score.

Left ventricular ejection fractionfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Left ventricular ejection fraction (first, last, best, worst), determined by ultrasound will be noted.

Arrhythmiasfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Presence of arrhythmias and the need for treating them will be recorded.

Serum troponin levelfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Serum troponin levels will be determined (on admission, minimal, maximal).

Vasopressor and/or inotrope needfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

The need for vasopressors and inotropes will be noted, along with the name of the substance, maximal dosage and duration.

Kidney failurefrom admission until 14 days or till discharge from ICU or death (whatever comes first)

The need for renal replacement therapy (and consecutive day of such therapy) will be recorded.

Serum creatinine levelsfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Serum creatinine levels will be recorded (on admission, minimal, maximal).

Serum procalcitonin levelsfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Serum procalcitonin levels will be determined (on admission, minimal, maximal).

Serum urea levelsfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Serum levels of urea will be recorded (on admission, minimal, maximal).

Serum C-reactive protein levelsfrom admission until 14 days or till discharge from ICU or death (whatever comes first)

Serum C-reactive protein levels will be determined (on admission, minimal, maximal).

Trial Locations

Locations (1)

University Medical Centre Maribor

🇸🇮

Maribor, Slovenia

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