The purpose of this study was to determine the correlation between change in respiratory muscle strength and change in cough ability in patients submitted to open-heart surgery. An observational cross-sectional study was conducted among 52 participants. Respiratory muscle strength was assessed by maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) using a respiratory pressure meter. Cough ability was evaluated by voluntary expiratory peak flow (PEF) using a digital spirometer. Evaluations were performed on the day of admission and discharge. Post-operative MIP, MEP, and PEF were significantly lower than those evaluated preoperatively (all p < 0.001). The difference of MIP and MEP was substantial positively correlated with the change in PEF in both absolute and predicted values (all p < 0.001) with the changes in MIP was highly relation. This study demonstrated that weakness of respiratory muscles, especially inspiratory muscle, was correlated to declining in cough ability in patients who had undergone open-heart surgery.
___
1.Morsch KT, Leguisamo CP, Camargo MD, et al. Ventilatory profile of patients undergoing CABG surgery. Rev Bras Cir Cardiovasc 2009; 24: 180- 187.
2. Barros GF, Santos Cda S, Granado FB, Costa PT, Limaco RP, Gardenghi G. Respiratory muscle training in patients submitted to coronary arterial bypass graft. Rev Bras Cir Cardiovasc 2010; 25: 483-490.
3. Savci S, Degirmenci B, Saglam M, et al. Shortterm effects of inspiratory muscle training in coronary artery bypass graft surgery: a randomized controlled trial. Scand Cardiovasc J 2011; 45: 286-293.
4. Weissman C. Pulmonary complications after cardiac surgery. Semin Cardiothorac Vasc Anesth 2004; 8: 185-211.
5. Wynne R, Botti M. Postoperative pulmonary dysfunction in adults after cardiac surgery with cardiopulmonary bypass: clinical significance and implications for practice. Am J Crit Care 2004; 13: 384-393.
6. Park JH, Kang SW, Lee SC, Choi WA, Kim DH. How Respiratory Muscle Strength Correlates with Cough Capacity in Patients with Respiratory Muscle Weakness. Yonsei Med J 2010; 51: 392- 397.
7. McCool FD. Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines. Chest 2006; 129: 48- 53.
8. Mustafa KY, Nour MM, Shuhaiber H, Yousof AM. Pulmonary function before and sequentially after valve replacement surgery with correlation to preoperative hemodynamic data. Am Rev Respir Dis 1984; 130: 400-406.
9. American Thoracic Society/European Respiratory Society. ATS/ERS Statement on respiratory muscle testing. Am J Respir Crit Care Med 2002; 166: 518-624.
10. Neder JA, Andreoni S, Lerario MC, Nery LE. Reference values for lung function tests. II. Maximal respiratory pressures and voluntary ventilation. Braz J Med Biol Res 1999;32:719-727.
11. Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J 2005; 26: 319-338.
12. Dejsomritrutai W, Nana A, Maranetra KN, et al. Reference spirometric values for healthy lifetime nonsmokers in Thailand. J Med Assoc Thai 2000; 83: 457-466.
13. Cavenaghi S, Ferreira LL, Marino LH, Lamari NM. Respiratory physiotherapy in the pre and postoperative myocardial revascularization surgery. Rev Bras Cir Cardiovasc 2011; 26: 455- 461.
14. Gimenes C, de Godoy I, Padovani CR, Gimenes R, Okoshi MP, Okoshi K. Respiratory pressures and expiratory peak flow rate of patients undergoing coronary artery bypass graft surgery. Med Sci Monit 2012; 18: CR558-563.
15. Kang SW, Kang YS, Sohn HS, Park JH, Moon JH. Respiratory muscle strength and cough capacity in patients with Duchenne muscular dystrophy. Yonsei Med J 2006; 47: 184-190.
16. Jo MR, Kim NS. The correlation of respiratory muscle strength and cough capacity in stroke patients. J Phys Ther Sci 2016; 28: 2803-2805.