The Effects of Peep and Tidal Volume on Oxidative Stress in Cardiopulmonary Bypass Surgery
Condition: Cardiac Surgery; Oxidative Stress
Study type: Observational

Summary: 
      Although cardio-pulmonary bypass surgery (CPBS) is a routine procedure worldwide, patient
      morbidity and mortality are still high due to postoperative negative
      complications.Inflammatory response and systemic oxidative stress have been reported to be
      directly related to this practice.Mechanisms explaining this condition have been described as
      being related to several events that occur during the cardiopulmonary bypass (CPBS), where
      blood is exposed to non-physiological surfaces, surgical trauma, ischemia-reperfusion, and
      changes in body temperature.In addition, CPB induces atelectasis and affects the structure of
      the bronchoalveolar tree.Prolongation of atelectasis may facilitate proinflammatory cytokine
      production by macrophages.One of the most damaging consequences of all these events is the
      formation of reactive oxygen species (ROS) and radicals originating from various cellular and
      enzymatic sources such as myocardial cells, activated neutrophils.ROS has toxic effects on
      cellular structures including lipids, proteins and nucleic acids.Oxidative reaction damages
      cellular function and may increase perioperative or postoperative complications after
      CPBS.Total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index
      (OSI) reflect the redox balance between oxidation and antioxidation.TAS measurement is an
      indication of the activity of all antioxidants and TOS is an indicator of ROS.OSI is a
      measure of the ratio of TOS to TAS and the level of Oxidative Stress (OS).The contribution of
      various mechanisms to oxidant-antioxidant balance during on-pump coronary artery bypass
      grafting (ONCABG) has not yet been fully evaluated. The investigator's aim in this study is
      to investigate the effect of lung protective mechanism (Tidal Volum, PEEP) on oxidative
      stress parameters such as TAS, TOS, Thiol / Disulphide, Catalase, Glutathione Peroxidase, MDA
      (Melanil Dialdehyde) in cardio pulmonary bypass surgery
    

Detailed description: 
      The study will be performed on patients who accept cardiopulmonary by-pass surgery, the
      conscious openness to participate in the study.Age, sex, body mass index (BMI), smoking
      habits, diagnosis, additional diseases, drugs used, surgery, intervention, anesthetic agents
      used in induction and dyspepsia, peroperative supportive treatments, left ventricular
      ejection fraction, post operative blood and TDP amount CPB (cardiopulmonary bypass) time
      (min), Cross clamp time (min), cardioplegia amount and type, analgesic name and dose made,
      duration of operation, name of postoperative and perioperative support treatments ,
      perioperative and post operative intake and urine output,postoperative extubation time,
      intensive care day of hospitalization, day of hospitalization will be recorded.The study was
      planned in 3 groups.Group 1 mechanical ventilator closed group (mechanical ventilator off)
      FiO2; 50%, Flow: 2 L / min. 2 Group Tidal Volume 3-4ml / kg (TV), FIO2 50%, Flow: 2L / min,
      Frequency; 10-12 applied group. 3. Group Tidal Volume 3-4 ml / kg, PEEP: 5 cm H2O pressure,
      FIO2 50%, Flow: 2 L / min, Frequency:Planned to be the 10-12 applied group.Pre-operative,
      operative (After the cross clamp is removed) and postoperative (postoperative 24th hour)
      blood will be collected from patients participating in the study.Thiol / Disulphide, MDA,
      TAS, TOS, Catalase and Glutathione Peroxidase will be studied. All patients should be
      premedicated with 0.1 mg / kg midazolam.Fentanyl (5-8 μg / kg), and rocuronium (0.5 mg / kg)
      will be used for induction of anesthesia. During anesthesia, 2% sevoflurane will be
      used.Arterial cannula to be inserted.Central venous catheter and urinary catheter will be
      placed. 3 - 5 mg / heparin and cardioplegia will be applied.The active clotting time (ACT)
      will be kept above 400.Heparin 1: to be neutralized with 1.3% of the Protamine.In the
      postoperative period, all patients will be transferred to the intensive care unit.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients who will be cardiopulmonary by-pass surgery and volunteer to participate in the
        study will be included in the study.
      
Keywords: peep, tidal volume, cardiopulmonary bypass, oxidative stress