Investigating the Pulmonary Function Parameters following Coronary Artery Bypass Surgery in Patients with General Anesthesia and General Anesthesia with Spinal Anesthesia

Investigating the pulmonary function parameters following coronary artery bypass surgery in patients with general anesthesia and general anesthesia with spinal anesthesia.

Patients are randomly divided into intervention and control groups and the study design is a randomized, controlled, parallel-group trial with double blinded outcome assessment. Randomization is centralized based on simple randomization method using random digits table. phase 3, sample size 60

Sixty patients candidate of coronary artery bypass surgery in age group 40 to 65 years in Ahvaz Imam Khomeini hospital are studied into intervention and control group (n=30). Participants, researchers responsible for data collection and analyses are blind to the groups allocation.

Inclusion criteria are male patients who are candidates for coronary artery bypass surgery in age group 40 to 65 years; The exclusion criteria are patients with history of cardiac surgery, history of coagulopathy, antiplatelet consumption before surgery, severe lumbar deformity or BMI greater than 35, contraindication of neuro-axial block and systemic or local infection.

In control group, general anesthesia is administered intravenously with midazolam 2 mg, fentanyl 3 µg/kg, lidocaine (20%) 1.5 mg/kg, thiopental sodium 3 mg/kg and atracurium 0.6 mg/kg and in the intervention group, before induction of general anesthesia, spinal anesthesia is performed with intrathecal injection of 20 mg bupivacaine 0.5% on sitting position in L3-L4 midline space with needle gauge 25.

Tidal volume, vital capacity, the partial pressure of oxygen and carbon dioxide and blood PH in 1, 2, 4, 6 and 12 hours after extubation are measured.

Individuals are randomly divided into two groups based on simple randomization method using random digits table. In this method, a collection of non-template numbers is randomly generated and arranged as a table. Even numbers for the intervention group and the odd numbers for the control group are considered. According to the number of patients, they are randomly assigned to one of the intervention or control groups.

Participants are informed about the purpose and method of study. After receiving informed consent, they are blinded to the study groups to unify patients in terms of their induction sense. Researchers responsible for data collection and analyses are also blind to the groups allocation.