Impact of Ascorbic Acid Treatment on the Development and Treatment of Vasodilation in Cardiac Surgery

Study Overview
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Brief Summary
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This is a prospective pilot study in which the effects of ascorbic acid administration are investigated in adult patients undergoing cardiac surgical procedures requiring cardiopulmonary bypass (CPB). Ascorbic acid (Vitamin C) is an essential cofactor in the biosynthesis of catecholamines, and critically ill patients are known to be ascorbate-deficient. In addition, cardiopulmonary bypass (CPB) decreases ascorbic acid concentrations. Cardiac vasoplegia is the loss of vascular tone despite adequate volume status and cardiac output, occurring commonly in patients after CPB. This necessitates the administration of vasopressors and alternative agents which can have deleterious effects. The administration of ascorbic acid to cardiac surgical patients may improve microcirculatory function, enhance endogenous catecholamine levels and decrease the need for exogenous vasopressor support.

Detailed Description
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1. Specific Aims The investigators aim to determine the feasibility of performing a study that can assess the impact of ascorbic acid administration on the development and severity of cardiac vasoplegia in cardiac surgical patients undergoing procedures at high risk for vasoplegia. Specific Aim 1: Determine the feasibility of administration of high dose intravenous ascorbic acid in the operative and post-operative environments as well as sample size for a prospective, randomized, placebo controlled study. Specific Aim 2: Determine baseline ascorbic acid plasma levels in a small cohort of cardiac surgical patients. Specific Aim 3: Determine the impact of ascorbic acid administration on microvasculature as measured by dark field microscopy.

Official Title
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Pilot Study for Determining the Impact of Ascorbic Acid Treatment on the Development and Treatment of Vasodilation in Cardiac Surgery

Conditions
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Vasoplegia

Intervention / Treatment
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* Drug: Ascorbic Acid


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: 18 years of age or older Undergoing cardiac surgery with the use of cardiopulmonary bypass Undergoing myectomy or valve replacement/repair Exclusion criteria: Coronary artery bypass grafting (CABG) Circulatory arrest Active infection or sepsis Severe hepatic disease or ascites Pre-operative renal dysfunction requiring dialysis Pre-operative midodrine Pre-operative oral or intravenous steroid use

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment<br>All patients will receive ascorbic acid as this is a pilot study. | Drug: Ascorbic Acid<br>* Patients will receive IV ascorbic acid.<br>* Other names: Ascor;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vasopressor duration in hours | Total duration of vasopressor therapy | Up to 10 days following surgery | 
| Vasopressor dose | Total dose of vasopressor in norepinephrine equivalents (mcg) | Up to 10 days following surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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vasoplegia, cardiac surgery, ascorbic acid