IRCT2013081714377N1 IRCT 2013-10-26 Vice chancellor for research Lorestan University of Medical Sciences The effect of positive end expiratory pressure on the incidence of pulmonary complications. Effect of positive end expiratory pressure, five and ten cm H2O on the incidence of pulmonary complications in patients undergoing coronary artery bypass surgery. 2013-08-01 anticipated 90 Complete https://irct.ir/trial/14045 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Prevention, Other design features: Patients as stratified block are randomly divided into two groups of control and intervention. Because statistical specialists, patients and nurses are measuring variables of random assignment were not aware of the researcher is aware of the random assignment of subjects to be considered, therefore, double-blind study. N/A Coronary artery bypass graft. Intervention 1: If the patient is in control group، from arrival to the Intensivel Care Unit to extubation time he will get the amount of 5 cm H2O of positive end expiratory pressure. Intervention 2: Patients in intervention group، if hemodynamic status is not disrupted، will get for 4 hours an average of PEEP of 10 cm H2O and until extubation time، PEEP of 5 cm H2O will be received.