Contrasting effects of three breathing techniques on pulmonary function, functional capacity and daily life functional tasks in patients following valve replacement surgery- A pilot randomized clinical trial

Background: Valve replacement surgeries affect the physiological mechanisms of patients leading to various postoperative pulmonary complications. Lung expansion therapy consisting of numerous techniques is routinely used for the prevention and treatment of these complications. Objectives: Our study aimed to compare the effects of diaphragmatic breathing (DB), flow (FS) and volume-oriented incentive spirometer (VS) in patients following valve replacement surgery. Methods: 29 patients posted valve replacement surgeries were randomly assigned to VS, FS and DB groups. Patients underwent preoperative training and seven-day rehabilitation post-surgery. Pulmonary function tests were performed before surgery and for seven days afterward. On the seventh postoperative day, patients performed a six-minute walk test and completed a functional difficulties questionnaire (FDQ). Results: Pulmonary function test values reduced in all three groups postoperatively when compared to the preoperative values but improved by the seventh postoperative day (p < 0.05). On comparing the seventh postoperative day values to the preoperative values, the VS group had no significant difference (p = 1.00) (Forced Vital Capacity- % change: DB-37.76, VS-1.59, FS-27.98), indicating that the value had nearly returned to the baseline. As compared to the DB and FS groups, FVC showed a greater improvement in the VS group (p = 0.01 and p = 0.06 respectively). No significant differences were observed between groups for distance walked (p > 0.05), however, FDQ scores demonstrated positive changes in favor of VS when contrasted with FS or DB (p < 0.05). Conclusion: Diaphragmatic breathing, flow or volume-oriented spirometer could improve pulmonary function in the postoperative period. The volume-oriented spirometer, however, was found to be the most beneficial among the three techniques in improving patients’ pulmonary function and daily life functional tasks. Further research is warranted to confirm these findings.