Effect of breather device on respiratory muscle strength and quality of life in coronary artery bypass grafting patients: A randomised control trial protocol

Introduction

Coronary artery bypass grafting (CABG) is still well-established option for treating coronary artery disease (CAD), and it frequently performed along with other coronary surgical procedures for multiple vessel disease.¹ The World Health Organisation reports that, in underdeveloped nations, CAD is the leading cause of mortality. It is responsible for roughly 13.7% of all deaths (5.27 million deaths).² More than 32 million people in India currently suffer from CAD.³ This is primarily due to the rapid and unplanned urbanization that is occurring in traditional civilizations, which has resulted in a lifestyle marked by decreased physical activity, smoking, and poor diet. This unhealthy way of life is associated to considerable risk factors for CAD, including obesity, hypertension, and diabetes mellitus.⁴

Issues with the cardiovascular system following CABG surgery, as well as frequently occurring post-operative complications include respiratory failure, stroke, urinary tract infections, renal failure, coagulopathy, limb ischemia, wound dehiscence, pleural effusion, and hematologic abnormalities.⁵ Physiotherapy helps to recover more quickly for high-risk and low-risk patients in coronary artery bypass surgery.⁶ and helps them attain functional independence,⁷ resulting in an improvement in these individuals overall health state following surgery.⁸

To avoid or lessen post-operative pulmonary problems, patients undergoing heart surgery are frequently recommended chest physical therapy and breathing exercises.⁹ There is a consensus regarding the importance of physiotherapy and pre-and post-operative breathing exercises.^8–10 There is a positive effect of the six-minute walk test as it reduces long-term mortality and is useful to optimize pre-operative study.¹¹

Expiratory muscle strength training (EMST) or inspiratory muscle strength training (IMST) have both been demonstrated to have positive effects on respiration.¹² The Breather (PN Medical, USA) which combines therapeutic exercise equipment with resistance training for the breathing and exhalation muscles, was the first respiratory muscle training (RMT) product to be granted a U.S. patent.¹³ These components are typically present in varying degrees in the most prevalent types of RMT.¹⁴ Anxiety level at the time of surgery may have an impact on postoperative recovery.¹⁵

The Breather is a breathing apparatus that uses resistance to train the respiratory muscles while allowing users to breathe via orifices of varying sizes.¹⁶ Breathing exercises are used as one of the therapeutic modalities to reduce symptoms and enhance respiratory function.¹⁷ It helps people breathe properly and effectively as well as strengthen the respiratory muscles.¹⁸ Cardiac rehabilitation helps in reduce anxiety, depression and hence improving the overall heath of the patients.^19,20

There is a need for a study to evaluate the effectiveness of a breather device in assessing respiratory muscle strength and quality of life in CABG patients because there is little research demonstrating its effectiveness in these patients.

Protocol

Study participants will be recruited from CVTS ICU and CVTS ward, Acharya Vinoba Bhave Rural Hospital, Sawangi (Meghe), Wardha, Maharashtra, after approval is received from the institutional ethics committee of Datta Meghe Institute of Higher Education and Research for the study. Subjects will be approached and screened for the criteria process of this study. A randomised approach utilizing sequentially numbered opaque sealed envelope (SNOSE) technique will be used for members allocation. The study will be open-label, and individuals will be invited based on inclusion and exclusion criteria while taking into account cut-off values at baseline parameters. Throughout the month-long recruitment phase, recruitment from a second source will be used if more study participants are needed. The study is a parallel-group RCT with two arms for a subject allocation ratio (1:1) and will be carried out for 12 months. The device for the study will be funded by the university with ethical committee approval. To determine efficacy, the control group will undergo standard chest physiotherapy while the active group will utilize the Breather device. Results on the marginal difference for respiratory muscle strength and quality of life endpoint will be analysed. The following clinic visits will be held at the same time and in the same order: visit 1 for subject enrolment, visit 2 for participant screening, and visits 1 and 3 for the measurement of baseline, week 3 at primary, and secondary parameters. The article will be published in an indexed journal.

Sample size calculation

Study setting

This study will be carried out in the CVTS ICU and ward of Acharya Vinoba Bhave Rural Hospital, Sawangi, Wardha.

Targeted population

CABG patients from age group of 30-60 years.

Sampling technique

Simple random sampling technique

Allocation

Sequentially numbered opaque sealed envelope (SNOSE) technique

Sample size

The mean difference formula will be used.

$$n1=n2=2\frac{{\left(Z_{\alpha }+Z_{\beta }\right)}^2{\sigma }^2}{{\left(\delta \right)}^2}$$

Primary variable = respiratory muscle strength

Difference (mean ± SD) result in respiratory muscle strength for conventional chest therapy = 4.33 ± 3.20. (As per reference article).¹⁸

Clinically relevant superiority = 40 % = (4.33×40)/100 = 1.7

As per reference articles.¹⁸

$$N1=2\times \left[\left(1.64+0.84\right)2\left(3.20\right)2\right]/\left(1.7\right)2=40$$

Total samples required = 44 per group.

Considering 10% drop out = 4

The total sample size required = 88

Notations:

$$Z_{\alpha }=1.64$$

$$\alpha =\text{Type}I\text{error}\mathrm{at}\text{both the side}10\%$$

$$Z_{\beta }=0.84\left(1-\beta \right)=\text{Power}\mathrm{at}80\%$$

$$\sigma =\text{stdandard deviation}3.2$$

Reference article: Effect of Inspiratory Muscle Training by Using Breather Device in Participants with Chronic Obstructive Pulmonary Disease (COPD).¹⁸

The study duration will be one year. The trial workflow is shown in Figure 1.

Figure 1. Trial workflow.

Discussion

For coronary disease the most established method is CABG. In cardiac surgery reduced respiratory muscle strength has been associated with decreased functional capacity, contributing to a protracted period of recovery of lung function which can linger for several weeks. Respiratory effects include alterations in lung capacities and sizes, alveolar dysfunction, a decrease in central respiratory stimulation, and mechanical problems with respiratory function.

Following CABG, patients frequently experience pain, discomfort, depressive symptoms, impatience, a loss of overall well-being, and an inability to perform at their pre-surgery levels. The patient’s quality of life may be substantially compromised by these emotions. Initiatives for the enhancement of care can be directed by monitoring ICU length of stay (LOS) following CABG and looking at its risk factors. However, few studies have looked at this problem from a personal, clinical, and ICU care demands perspective.

Campos de Menezes et al. (2018) undertook research to assess the strength of the peripheral and respiratory muscles following heart surgery. According to the study, there is a reduction in respiratory and limb muscle strength following heart surgery. These factors must be taken into account, especially respiratory and peripheral muscular strength.²¹

In Shaikh et al. (2019)’s study, “Effect of Breather Device-Assisted Inspiratory Muscle Training on Participants with COPD Disease”, 30 participants both male and female, were divided into two groups and subjected to two weeks of diaphragmatic breathing exercises in Group B and two weeks of inspiratory muscle training with a breather device in Group A. The study showed that the Pimax and 6MWD scores of persons with COPD who utilized a breather device for IMT significantly improved.¹⁸

Bausek et al. (2019) conducted a pilot study that revealed the effect of resistive RMT on the feasibility and quality of a home-based COPD care program. Respiratory Muscle Training Improves Speech and Pulmonary Function in COPD Patients in a Home Health Setting. During a four-week pilot period, the peak expiratory flow increased and the maximum phonation duration increased.²²

Robert J. Arnold et al.’s (2020) study was conducted on 20 individuals with stroke followed by dysphagia to check the effectiveness for function of swallowing by improving the inspiratory-expiratory muscle strength using the breather device as the interventional group for 28 days. This concluded that the combined RMT is an effective technique to improve symptoms of dysphagia with improving airway.²³

The breather device uses resistance to help strengthen the muscle used in respiration. This can help in improving strength of respiratory which leads to improving in their quality of life. It also helps in reduced the complication after the cardiac surgery which makes them adaptive sedentary lifestyle. This breather device can help improving this variable along with conventional chest physiotherapy.