Open cardiac surgery is an important treatment method that is frequently used in the treatment of complicated atherosclerotic ischemic heart disease and heart valve diseases.

It is emphasized that respiratory functions decrease significantly after cardiac surgery, especially in the immediate post-operative period. Therefore, despite significant progress in the field of cardiopulmonary bypass and anesthesia technique, pulmonary complications after cardiac surgery are still seen as the main cause of other negative outcomes such as morbidity, mortality, and long-term hospitalization.

Cardiac surgery patients are especially at high risk for the development of postoperative pulmonary complications (PPC).

It has been reported that deep breathing exercises improve postoperative lung expansion and ventilation, resulting in a significant reduction in pulmonary complications.

Postoperative respiratory physiotherapy techniques include techniques such as early mobilization, positioning, breathing exercises, active breathing techniques cycle, as well as the use of different mechanical devices such as incentive spirometry (IS), positive expiratory pressure mask therapy, and continuous positive airway pressure. Incentive spirometry (IS) is a mechanical breathing device that provides slow deep breathing and gives visual feedback and is used as one of the important interventions in the prevention of PPC in patients who have been undergoing open heart surgery for many years.

In studies examining the effectiveness of deep breathing exercise with IS on the development of PPC in open cardiac surgery patients, it is seen that IS application is performed in the postoperative period , it is noteworthy that there is no study examining the effectiveness of preoperative IS application. In the light of this information, the aim of this study is to evaluate the effect of deep breathing exercise with incentive spirometry initiated in the preoperative period on pulmonary function and complications in patients undergoing open heart surgery.

Open cardiac surgery is an important treatment method that is frequently used in the treatment of complicated atherosclerotic ischemic heart disease and heart valve diseases. Complications after cardiac surgery include; supraventricular tachycardia, atrial fibrillation, bradycardia, perioperative myocardial infarction, cardiac arrest, Postoperative pulmonary complications (PPC) such as pneumonia, atelectasis and pleural effusion . It is emphasized that respiratory functions decrease significantly after cardiac surgery, especially in the immediate post-operative period. Therefore, despite significant progress in the field of cardiopulmonary bypass and anesthesia technique, pulmonary complications after cardiac surgery are still seen as the main cause of other negative outcomes such as morbidity, mortality, and long-term hospitalization. Cardiac surgery patients are especially at high risk for the development of PPC. In approximately one-quarter of patients who undergo cardiac surgery without chronic respiratory dysfunction, a mild respiratory tract infection develops ranging from oxygen therapy to acute respiratory failure requiring invasive or non-invasive mechanical ventilation support. Among the factors that cause the development of PPC; surgical stress and anesthesia, cardiopulmonary bypass causing a systemic inflammatory response and oxidative stress that causes pulmonary ischemia-reperfusion injury, type of surgery, pain management, anesthesia protocol, use of blood products, and diaphragmatic dysfunction.

Despite advances in surgical technique and pre- and postoperative care practices in cardiac surgery, PPC is still an important problem. PPC, cost of patient care, increased morbidity and mortality and length of hospital stay elongation. Due to the absence of effective deep inspiration and coughing due to postoperative pain and anxiety, secretion accumulation and gas exchange are ineffective. In a study, it was determined that after coronary artery bypass graft (CABG), 1-20% of patients were hospitalized again in the first 30 days after discharge due to respiratory system complications and 0.4-22.5% of pleural effusion. Various respiratory physiotherapy methods are used for the prevention and treatment of PPC after cardiac surgery. The main purpose of respiratory physiotherapy is to improve ventilation-perfusion compatibility, increase lung volume, increase mucociliary clearance and reduce pain. It has been reported that deep breathing exercises improve postoperative lung expansion and ventilation, resulting in a significant reduction in pulmonary complications. Postoperative respiratory physiotherapy techniques include techniques such as early mobilization, positioning, breathing exercises, active breathing techniques cycle, as well as the use of different mechanical devices such as incentive spirometry (IS), positive expiratory pressure mask therapy, and continuous positive airway pressure. Incentive spirometry (IS) is a mechanical breathing device that provides slow deep breathing and gives visual feedback and is used as one of the important interventions in the prevention of PPC in patients who have been undergoing open heart surgery for many years. Deep breathing exercise training with IS is given to the patients in the preoperative period, and its application is started in the postoperative period. However, it has been reported that insufficiency of physical adaptation and respiratory muscle weakness in the preoperative period are closely related to PPC, which causes prolonged hospital stay and increased mortality. In a meta-analysis study examining the effectiveness of preoperative exercise training for the prevention of PPC in adults undergoing major surgery, it was found that preoperative exercise training minimizes the use of hospital resources, improves physical fitness, and reduces the risk of developing PPC, regardless of the type of surgery. In a meta-analysis study examining the effectiveness of preoperative and postoperative rehabilitation in patients with lung cancer, it was determined that preoperative rehabilitation was effective in reducing postoperative pulmonary complications and hospital stay associated with lung cancer surgery. In studies examining the effectiveness of deep breathing exercise with IS on the development of PPC in cardiac surgery patients, it is seen that IS application is performed in the postoperative period, it is noteworthy that there is no study examining the effectiveness of preoperative IS application.

In the light of this information, the aim of this study is to evaluate the effect of deep breathing exercise with incentive spirometry initiated in the preoperative period on pulmonary function and complications in patients undergoing open heart surgery.

Research Hypotheses H1: Oxygen saturation measured using the pulse oximeter TBY200 will be significantly higher in patients undergoing open heart surgery and initiating deep breathing exercise with IS in the preoperative period.

H2: Arterial blood gas parameters (pH: 7.35-7.45, PaCO2:35-45 mmHg PaO2:80-100 mmHg, SaO2: 95-97%, HCO3:22-26 mEq/L) in patients who underwent open heart surgery and started deep breathing exercise with IS in the preoperative period will have significantly more normal values.

H3: Postoperative pulmonary complications will develop significantly less in patients undergoing open heart surgery and initiating deep breathing exercise with IS in the preoperative period.

H4: In patients undergoing open heart surgery and initiating deep breathing exercise with IS in the preoperative period, the duration of mechanical ventilation will be significantly shorter.

H5: In patients undergoing open heart surgery and initiating deep breathing exercise with IS in the preoperative period, the length of stay in the intensive care unit will be significantly shorter.

H6: In patients undergoing open heart surgery and initiating deep breathing exercise with IS in the preoperative period, the postoperative hospital stay will be significantly shorter.

Inclusion Criteria:

• 18 years and over,
• Able to speak and understand Turkish,
• Conscious, oriented and cooperative,
• First time undergoing cardiac surgery,
• In the Preoperative Chest Diseases Consultation, it was determined that there was no lung pathology and bronchodilator treatment was not started,
• Coronary artery bypass graft (CABG), heart valve surgery or combined open cardiac surgery,
• Having a score of 1 on the Medical Research Council Scale (MRCS),

Exclusion Criteria:

• Emergency surgical intervention applied,
• Complete (100%) occlusion of the left main coronary (LMCA) or right main coronary artery,
• With concomitant vascular aneurysm,
• Chronic respiratory system disease (Asthma, COPD, bronchiectasis, bullous lung, etc.),
• Those who do not agree to participate in the study,
• Died in the process of working,
• Patients for whom data cannot be collected will be excluded.