Effects of combined Triflow, deep breathing and coughing exercises on postoperative pulmonary function after mitral valve replacement: a randomized controlled trial

BACKGROUND: Postoperative pulmonary complications remain a major cause of morbidity after cardiac valve surgery. Although incentive spirometry (Triflow) is routinely used in postoperative care, evidence regarding the additional benefits of combining Triflow with deep breathing and coughing exercises remains limited. This study aimed to evaluate the effects of combined Triflow, deep breathing, and coughing exercises on postoperative pulmonary function in adult patients undergoing mitral valve replacement. METHODS: This randomized controlled, single-blind trial was conducted between May and August 2025 in a private hospital in Istanbul. A total of 60 adult patients undergoing mitral valve replacement were randomly allocated to an experimental group (n = 30) or a control group (n = 30) using simple randomization. The experimental group performed Triflow combined with deep breathing and coughing exercises, while the control group performed Triflow alone. RESULTS: Postoperative SpO₂ levels were significantly higher in the experimental group at T1 (p = 0.009; 95% CI: 0.46-3.14), T2 (p < 0.001; 95% CI: 1.57-3.43), and T3 (p < 0.001; 95% CI: 2.72-4.54). The FEV₁/FVC ratio increased significantly in the experimental group compared with the control group at discharge (p < 0.001; 95% CI: 4.46-6.41). Respiratory rate was significantly higher in the experimental group at T1 (p < 0.001; 95% CI: 1.68-4.45), T2 (p < 0.001; 95% CI: 3.34-6.26), and T3 (p < 0.001; 95% CI: 5.23-8.37). Hematocrit levels were significantly lower in the experimental group at T1 (p = 0.039; 95% CI: -8.32 to - 0.24), T2 (p = 0.007; 95% CI: -8.29 to - 1.40), and T3 (p = 0.034; 95% CI: -6.54 to - 0.28). Pain scores were significantly lower in the experimental group at T1 (p < 0.001; 95% CI: -2.82 to - 1.71) and T2 (p < 0.001; 95% CI: -1.98 to - 1.08). Time to first mobilization was significantly shorter in the experimental group (p < 0.001; 95% CI: -2.94 to - 1.26). No postoperative pulmonary complications were observed in either group. CONCLUSION: The combined application of Triflow, deep breathing, and coughing exercises was associated with significant improvements in postoperative pulmonary function, oxygen saturation, pain reduction, and earlier mobilization compared with Triflow alone in patients undergoing mitral valve replacement. These findings suggest that a structured, combined respiratory exercise protocol may provide additional clinical benefits in the early postoperative period. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT06997224 (First registered on 15 May 2025).