The effect of inspiratory muscle training and respiratory physiotherapy on pulmonary functions, respiratory muscle strength and functional capacity in patients who have undergone robotic hearth surgery

Important developments have been experienced in the field of cardiac surgery with the advancement of new technologies. It was aimed to reduce surgical-induced trauma in patients with robotic surgical methods performed by entering through smaller incision sites, but the risk of postoperative pulmonary complications could not be completely eliminated. In the literature, there is a consensus on the necessity of routine postoperative respiratory physiotherapy on patients who are operated by median sternotomy method. Although there are many studies on this field, there is no consensus on which technique is superior. However, there is no study about the effectiveness of respiratory physiotherapy and inspiratory muscle training on postoperative respiratory functions, respiratory muscle strength and functional capacity on patients who are operated with robotic surgery methods. Additional to this, although there are studies in the literature about postoperative pain in patients who have undergone robotic surgery, studies about dyspnea and fatigue are very limited. The aim of this study is to investigate the effects of comprehensive respiratory physiotherapy and additional inspiratory muscle training on respiratory functions, respiratory muscle strength and functional capacity in patients undergoing robotic surgery, and to analyze factors associated with fatigue, dyspnea and pain. In our study, 16 patients who were 18 years old and above, were eligible for surgery with robotic cardiac surgery method, accepted to undergo surgery and met the criteria, were included on a voluntary basis. The cases were randomly assigned to respiratory physiotherapy (SF) and inspiratory muscle training in addition to respiratory physiotherapy (SF-IMT) groups. Pulmonary function test (PFT), respiratory muscle strength test, 6-minute walking test (6MWT), lung diffusion capacity test (DLCO) were performed and fatigue severity scale (FSS), fatigue impact scale (FIS), basal dyspnea index (BDI) were questioned in all patients one day before surgery. Dyspnea and pain were additionally evaluated by using modified medical research council questionnaire (MMRC) and visual analog scale (VAS). After surgery, the SF group received a comprehensive respiratory physiotherapy program including diaphragmatic breathing, segmental breathing, pursed lip breathing, incentive spirometry and cough education, and the patients were administered an early mobilization protocol. In addition to the comprehensive respiratory physiotherapy program the SF-IMT group was given inspiratory muscle training (IMT) at 40% of the maximum inspiratory pressure (MIP) with the Threshold IMT® device in three sets of 10 repetitions twice a day. All evaluations were repeated at the end of four weeks, only PFT and respiratory muscle strength measurements were repeated on the fifth and 14th days postoperatively. Statistical analysis was done with the program RStudiotm (version 1.2.5042). All data were analyzed using Shapiro-Wilk test to determine distribution characteristics. In group comparisons "Paired Sample T-test" was used. In comparisons between groups "Independent Samples T-test" was used. "Repeated measures ANOVA" analysis was performed for intergroup and intragroup analysis of multiple measurements of the same parameter. Linear regression analysis was performed to determine the independent determinants of fatigue and dyspnea and to determine the effect level of respiratory parameters on fatigue and dyspnea. The significant level was accepted as p <0.05 for all analyzes. There was no statistically significant difference between preoperative demographic characteristics, respiratory functions, respiratory muscle strength, functional capacity, lung diffusion capacity, dyspnea and fatigue values of the patients in both groups. Surgery time and cardiopulmonary bypass time are found significantly higher in SF group than SF-IMT group (respectively p<0,018 ve p<0,003). In the SF-IMT group, when the forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), peak expiratory flow (PEF) predictive % values and MIP and maximum expiratory pressure (MEP) values measured before and on the fifth day were compared, statistically significant decrease was found (p <0.05), but when the fifth day and 28th day values were compared, a significant increase was found in these values (p<0.05). In the SF group, postoperative fifth day FVC, FEV1 and PEF predictive % values and MIP values were found significantly lower when compared with the preoperative values, but when the fifth day and 28th day values were compared (p<0.05), significant increase was found in these values (p<0.05), additionally significant increase was found in MEP value (p<0.05). In the SF group, there is a significant decrease between the preoperative and postoperative 28th day values of 6MWD and DLCO values (p <0.05), the decrease in 6MWD and DLCO values due to surgery did not return the preoperative levels despite comprehensive respiratory physiotherapy. In the SF + IMT group, it was observed that only the DLCO value did not return to the preoperative level, but the 6MWD value returned. When the changes in SF-IMT and SF groups were compared with each other, the increase in MIP, MEP and 6DYM values of the SF-IMT group were found to be significantly higher than the increase in the SF-group values (respectively p<0,001, p<0,05, p<0,001). In addition, preoperative values in fatigue and dyspnea parameters and 28th day values after surgery and physiotherapy treatment protocol were found to be similar in both groups (p>0,05). When the postoperative fifth and 28th day pain values were compared in both groups, a significant decrease was observed (p<0,05). As a result of our study, it has been found that comprehensive respiratory physiotherapy, which includes breathing exercises, incentive spirometry, cough training and early mobilization and applied for four weeks after the first day of surgery in patients with robotic heart surgery, has contributed to improve respiratory muscle strength and respiratory function values which decreased due to surgery in the SF and SF-IMT groups. In the SF-IMT group in which IMT was applied in addition to comprehensive respiratory physiotherapy, also the functional capacity value reached the preoperative level.