Background: Cardiac valve replacement surgery is frequently associated with postoperative pulmonary dysfunction resulting from anesthesia, surgical trauma, pain, and reduced mobility. These factors may lead to decreased lung volumes, impaired gas exchange, and an increased risk of postoperative pulmonary complications. Physiotherapeutic interventions such as Incentive Spirometry (IS) and Deep Breathing Exercises (DBE) are commonly used to enhance pulmonary function and facilitate postoperative recovery; however, evidence regarding their comparative effectiveness remains limited.

Aim: To compare the effectiveness of Incentive Spirometry and Deep Breathing Exercises on pulmonary function in patients following cardiac valve replacement surgery.

Methods: A randomized comparative study was conducted in a tertiary care cardiac center involving 60 patients who underwent elective cardiac valve replacement surgery. Participants were randomly allocated into two groups of 30 each. Group A received Incentive Spirometry, while Group B performed Deep Breathing Exercises. Both interventions were administered every two hours during waking hours for seven consecutive postoperative days under physiotherapist supervision. In addition, all participants received standardized postoperative physiotherapy care, including early mobilization, airway clearance techniques, and patient education. Pulmonary function was assessed using Forced Vital Capacity (FVC), Forced Expiratory Volume in One Second (FEV₁), Peak Expiratory Flow Rate (PEFR), and Oxygen Saturation (SpO₂). Measurements were recorded at baseline and on postoperative Day 7. Data were analyzed using paired and independent t-tests, with the level of significance set at p < 0.05.

Results: Intragroup analysis demonstrated highly significant improvements in all pulmonary function parameters within both groups (p < 0.001). Group A showed mean improvements of 21.07 units in FVC, 18.93 units in FEV₁, 17.20 units in PEFR, and 23.20 units in SpO₂. Group B demonstrated mean improvements of 19.80 units in FVC, 24.00 units in FEV₁, 19.80 units in PEFR, and 24.33 units in SpO₂. However, intergroup comparison using the independent t-test revealed no statistically significant differences between Group A and Group B in FVC (t = 0.82, p > 0.05), FEV₁ (t = 1.79, p > 0.05), PEFR (t = 0.49, p > 0.05), and SpO₂ (t = 1.12, p > 0.05).

Conclusion: Both Incentive Spirometry and Deep Breathing Exercises were effective in significantly improving pulmonary function and oxygen saturation following cardiac valve replacement surgery. However, neither intervention demonstrated superiority over the other. Therefore, both techniques may be considered equally effective and can be incorporated into routine postoperative cardiothoracic rehabilitation programs based on patient preference, clinical requirements, and resource availability.