Assessment the Effect of Positive End-Expiratory Pressure (PEEP) of 15 CmH2O on the Amount of Bleeding After Emergency Coronary Artery Bypass Surgery (CABG) without Using Cardiopulmonary Bypass Pump.

ِDetermination the Effect of Positive End-Expiratory Pressure (PEEP) of 15 CmH2O on the Amount of Bleeding After Emergency Coronary Artery Bypass Surgery (CABG) without Using Cardiopulmonary Bypass Pump.

Blocking (blocks of four) Due to the lack of similar study and the pilot of this research, as well as the number of patients in other studies, the sample size was considered to be 50 patients in each group. This study has been proposed as a hypothesis by the researchers, and due to the lack of similar studies, it is only predicted that there is a difference in the reduction of bleeding after the operation. Considering the conditions of these patients and the importance of the issue, any reduction in bleeding is important.

All patients referred to the cardiac emergency of Imam Reza & Qaim hospitals with coronary artery occlusion who candidates for emergency coronary artery bypass surgery.

Inclusion criteria: All patients who have been diagnosed with coronary artery occlusion and referred to the cardiac emergency department of Imam Reza and Qaim Hospital and after performing the initial diagnostic procedures, are candidates for emergency Coronary artery bypass surgery Exclusion criteria: Patient's death, lack of consent to participate in the study

In the intervention group, after bypass operation and usual treatment, including FFP injection, tranexamic acid, platelet injection and if necessary, return to the operating room, etc., patients in the ICU were treated with PEEP equivalent to 15 cm H2O until ventilators is needed. In the conventional treatment group, patients will be treated with PEEP equivalent to 5 cmH2O and other conventional treatments.

The amount of bleeding from pericardial and thoracic drains (in cc) in the first 6, 12, and 24 hours after surgery

Blocking (blocks of four)- In order to ensure an equal number of patients in the intervention and control groups, 2 patients are assigned to the intervention and 2 patients to the control in each block. Allocation of patients to intervention group and control group in each block is completely random. For example, the sequence of AABB- ABBA- BABA and... can be created in each block according to randomization.

Due to obtaining informed consent from the patients before entering the study, the patients do not know how to be assigned to the intervention or control group. Also, the data analyst does not know the group assigned to the patients.