The Effect of Guided Visualization Meditation on Surgical Stress Response in Patients Undergoing Cardiac Surgery: A Nonrandomized Controlled Clinical Trial

Major cardiac surgery triggers a strong neuroendocrine and psychological stress response, which can negatively affect postoperative recovery. The surgical stress response is primarily characterized by increased cortisol secretion, elevated blood glucose levels, insulin resistance, fluid retention, increased cardiac workload, and heightened anxiety. Excessive or prolonged stress response may contribute to complications, delayed healing, and extended intensive care or hospital stay. Reducing the magnitude of the surgical stress response is considered an important component of perioperative patient management.

Guided visualization meditation is a non-pharmacologic mind-body technique that uses structured verbal guidance, calming metaphors, and controlled breathing cues to help individuals focus attention on peaceful imagery. This technique may influence autonomic nervous system activity, reduce sympathetic arousal, and improve emotional regulation. Prior studies suggest that guided relaxation strategies can lead to reductions in cortisol, improvements in anxiety levels, and improved patient comfort. However, there is limited evidence regarding their effectiveness in patients undergoing open-heart surgery.

This study is designed as a non-randomized, controlled, interventional clinical trial with two parallel groups: an intervention group receiving guided visualization meditation and a control group receiving standard postoperative care. Each participant in the intervention group will listen to a 15-20 minute guided visualization audio recording with calming background music twice daily on three consecutive days: the day before surgery (T0), the day of surgery (T1), and the first postoperative day (T2). Audio will be delivered through headphones in a quiet clinical environment.

Primary outcomes will include serum cortisol levels measured at T0, T1 (six hours after extubation), and T2. Secondary outcomes will include serum glucose and insulin levels, State-Trait Anxiety Inventory scores (STAI-I and STAI-II), and pain scores assessed using a visual pain scale. All biochemical samples will be obtained by clinical staff following routine safety protocols. Anxiety and pain assessments will be completed face-to-face by trained research personnel.

Eligibility criteria include adults aged 18 or older scheduled for first-time on-pump cardiac surgery via median sternotomy, ASA I-II classification, mild to moderate hypothermia protocol, and the absence of psychiatric diagnoses or corticosteroid use. Patients experiencing complications, prolonged surgery, or altered postoperative consciousness will be excluded.