EFFECT OF POSTOPERATIVE HIGH INTENSITY LONG DURATION INSPIRATORY MUSCLE TRAINING ON PULMONARY FUNCTION AND FUNCTIONAL CAPACITY AFTER MITRAL VALVE REPLACEMENT

F. Hegazy^1,2, E. Aboelnasr^3,2, A. Hassan⁴, S. Mohamed Kamel⁵, A. Abdelhamid⁴, M. Elshazly⁴

¹University of Sharjah, Department of Physiotherapy, Sharjah, United Arab Emirates, ²Cairo University, Faculty of Physical Therapy, Giza, Egypt, ³Social Services Department, Government of Sharjah, Senior Citizens Physiotherapy and Rehabilitaion Center, Sharjah, United Arab Emirates, ⁴South Valley University, Faculty of Physical Therapy, Qena, Egypt, ⁵National Heart Institute, Department of Physiotherapy, Cairo, Egypt

Background: Although, pre-operative inspiratory muscle training has been investigated and reported to be an effective strategy to reduce postoperative pulmonary complications, the efficacy of postoperative inspiratory muscle training as well as the proper load, frequency, and duration necessary to reduce the postoperative pulmonary complications has not been fully investigated.

Purpose: This study designed to investigate the effect of postoperative high-load long-duration inspiratory muscle training on pulmonary function, inspiratory muscle strength, and functional capacity over time in patients who underwent mitral valve replacement surgery.

Methods: This study was conducted as a parallel-group, single-blind, single-center, randomized controlled trial with a follow-up of postoperative outcomes. A total of one hundred patients (mean age 38.3±3.29years) underwent mitral valve replacement surgery were randomized into experimental (n = 50) and control (n = 50) groups. The control group received conventional physiotherapy care, while experimental group received conventional care in addition to inspiratory muscle training, with 40% of the baseline maximal inspiratory pressure targeting a load of 80% by the end of the 8 weeks intervention protocol. Inspiratory muscle training started on the patient’s first day in the inpatient ward. Lung functions, inspiratory muscle strength, and functional capacity were evaluated using a computer-based spirometry system, maximal inspiratory pressure measurement and 6MWT respectively at 5 time points and a follow-up assessment was performed 6 months after surgery. Repeated measure ANOVA and post-hoc analyses were used (p <0.05).

Results: Group-time interactions were detected for all the studied variables (p<0.001). Between-group analysis revealed statistically significant postoperative improvements in all studied variables in the experimental group compared to the control group (p <0.001) with large effect size of η²˃0.14. Within-group analysis indicated substantial improvements in lung function, inspiratory pressure and functional capacity in the experimental group (p <0.05) over time, and these improvements were maintained at follow-up.

Conclusions: High intensity, long-duration postoperative inspiratory muscle training is highly effective in improving lung function, inspiratory muscle strength, and functional capacity after mitral valve replacement surgeries.

Implications: This study has valuable clinical implications as it presents promising clinical findings regarding the effect of using high intensity Inspiratory muscle training (IMT) for long duration (8 weeks). Using these parameters of IMT(starting intensity, targeted intensity, frequency, duration) that had been followed in this study, resulted in faster recovery of the pulmonary functions, inspiratory muscle strength and functional capacity after mitral valve replacement compared to the traditional protocol. Moreover, the results revealed that using high intensity IMT (more than 40% MIP) is a safe intervention in the early post-operative period after Mitral valve replacement surgery. Furthermore, this study findings highlighted and recommended that using IMT with staring load of 40% of the pre-operative IMT targeting 80% MIP for long duration (8 weeks) are effective parameters of the post-operative IMT to be used clinically as there were a paucity of literature regarding this point, that absolutely will have positive impact on improving and upgrading the evidence based clinical practice.

Funding acknowledgements: None

Keywords:
Inspiratory muscle training
Cardiopulmonary rehabilitation
Mitral valve replacement surgery

Topics:
Cardiorespiratory
Cardiorespiratory
Cardiorespiratory

Did this work require ethics approval? Yes

Institution: South Valley University

Committee: Human Research Ethics Committee of South Valley University.

Ethics number: SVU-2019-1265