Effect of Ascorbic Acid on Postoperative Pulmonary Complications in Patients Undergoing Cardiac Surgery

Study Overview
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Brief Summary
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Postoperative pulmonary complications(PPCs) including, but not limited to ,hypoxemia, pneumonia, ventilator-induced lung injury, and acute respiratory distress syndrome (ARDS),atelectasis,pleural effusion .PPCs may result in increased resources utilization, delayed mobilization, prolonged need of supplemental oxygen or mechanical ventilation,and a longer hospital stay.postoperative pulmonary complications are common after cardiac surgery, often increasing postoperative morbidity and mortality.The extracorporeal circulation,increased oxygen concentration inhaled and the development of massive atelectasis after open-chest surgery commonly activate lung inflammation, amplifying the harm Injury of pulmonary .Currently, plenty of interventions have been studied to prevent PPCs after surgery. Most of the recent research has focused on physical therapy such as lung-protective modes during intraoperative mechanical ventilation, Alveolar Recruitment, and respiratory muscle training.These therapies have a certain effect, but still not satisfactory.Ascorbic acid is an important cofactor in multiple enzymatic reactions where its main function is as a reducing agent.Studies have shown that ascorbic acid can reduce both ischemia-reperfusion injury and oxidative stress. Unfortunately, no studies examined whether Ascorbic acid can reduce PPCs.

Detailed Description
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The possible mechanisms of ascorbic acid to alleviate ischemia-reperfusion injury are as follows: 1 Ascorbic acid as a first-line antioxidant in plasma can reduce stress by eliminating excess Reactive oxygen species and reduce damage. 2 provides rapid electron transfer to react with superoxide and hydroxyl group to scavenge reactive oxygen released into the circulation. 3 Ascorbic acid can reduce lipid peroxidation and reduce lung injury caused by ischemia-reperfusion by scavenging oxygen free radicals. 4 Vitamin C can promote the production of cytokines by immune cells to reduce local inflammatory reactions and improve tissue microcirculation.The study aims to explore whether daily used Ascorbic acid in the perioperative period has a preventive effect on PPCs in patients undergoing cardiac surgery, and through short-term and long-term follow-up, to investigate the effect on post-hospitalization Prognosis .

Official Title
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Effect of Perioperative Application of Ascorbic Acid on Postoperative Pulmonary Complications in Patients Undergoing Cardiac Surgery

Conditions
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Postoperative Pulmonary Complications

Intervention / Treatment
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* Drug: Ascorbic Acid
* Drug: Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18-60 years old Selective cardiac surgery under cardiopulmonary bypass Exclusion Criteria: Emergency surgery Previous cardiac surgery Severe lung disease BMI<18 or >30 Mean pulmonary arterial pressure >40 mmHg were allergic to ascorbic acid

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ascorbic acid group<br>the patients received 2g of intravenous Ascorbic acid at the night before surgery, during the surgery and five days after surgery. | Drug: Ascorbic Acid<br>* Patients in Ascorbic acid group received 2g of intravenous Ascorbic acid at the night before surgery, during the surgery and five days after surgery (once a day).<br>* Other names: Vitamin c;|
| Placebo Comparator: Control comparator group<br>the patients received 10ml saline at the night before surgery, during the surgery and five days after surgery. | Drug: Saline<br>* Patients in Control Comparator group received saline 10ml at the night before surgery, during the surgery and five days after surgery (once a day).<br>* Other names: Saline Solution;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| severity of postoperative pulmonary complications | Use the postoperative pulmonary complications score to record the severity. scored ranging from 0 to 5.Scored the severity once a day, record the highest score. | an average of 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| incidence of postoperative pulmonary complications | incidence of postoperative pulmonary complications during hospital stay | an average of 10 days | 
| length of ICU stay and length of hospital stay | all patients transfer to ICU after surgery | an average of 10 days | 
| extubation and wake time | length of extubation time,length of wake time | an average of 1 day | 
| PaO2/FiO2 | Oxygenation index (PaO2/FiO2) in millimeter mercury column. | 1 day, 3 days,5 days post surgery | 
| A-aDO2 | alveolar-arterial oxygen tension difference (A-aDO2) | 1 day, 3 days,5 days post surgery | 
| Plateau pressure | Plateau pressure in centimeter water column | an average of 1 day | 
| Peak airway pressure | Peak airway pressure in centimeter water column | an average of 1 day | 
| positive end expiratory pressure | positive end expiratory pressure in centimeter water column | an average of 1 day | 
| lung compliance | lung compliance in Milliliter/ centimeter water column | an average of 1 day | 
| post-hospitalization follow-up | record the incidence of postoperative pulmonary complications after hospital discharged. | once a day till 30 days post-hospitalization |