Effectiveness of Respiratory Muscle Training on Respiratory Muscle Strength, Pulmonary Function, and Respiratory Complications in Stroke Survivors: A Systematic Review of Randomized Controlled Trials

Figures & data

Table 1 Summary of Included Studies

Author/Year	Characteristics of Participants	Outcome Measures	Interventions	Results	Conclusions
Sutbeyaz. ST et al 2010^Citation15	45 total participants: BRTG (n=15), IMTG (n=15), CG (n=15) -Mean age (years): BRTG;60.8 (6.8), IMTG;62.8 (7.2), CG;61.9 (6.15) Gender (Female/male): BRTG;7/8, IMTG;7/8, CG;7/8 Duration (days): BRTG;156 (49.7), IMTG;155.1 (46.9), CG;163.2 (36.5) Type of lesion (ischemic/hemorrhagic): BRTG;10/5, IMTG;12/3, CG;11/4	-FAC -BI -FVC -VC -FEV1 -FEV1/FVC	-EG: diaphragmatic breathing combined with pursed-lip breathing were given for 15 minutes, five days a week, 6 weeks durations. -CG: conventional stroke rehabilitation was given for five days a week for six-week period.	- Pulmonary function measures had no significant difference (FVC (P=0.41), VC (P=0.94), FEV1 (P=0.96), FEF 25–75% (P=0.28) and MVV (P=0.23)) in the BRT group compared with baseline and the control group. - PEF values were improved by the BRT intervention with a p value (p=0.01). Statistically significant improvement was observed in the IMT group regarding FVC (p=0.01), VC (p=0.01), FEV1 (p=0.01) and MVV (p<0.001) values compared with baseline and the control group.	-Risk of stroke and various forms of cardiovascular disease and stroke mortality might be reduced by respiratory muscle training.
Yoo H-J, Pyun S-B 2018^Citation16	40 total participants: EG (n=20), CG (n=20) Mean age (years): EG (n=57), CG (n=65) Female/male: IG;6/14, CG;8/12 Duration (days): IG;24 (11–95), CG;24.5 (11–95) Types of stroke: (ischemic/hemorrhagic) IG;11/9, CG;12/8	-FVC -FEV1 -BBS -Fugl-Meyer - pneumonia incidence	-EG: bedside respiratory muscle training and conventional stroke rehabilitation program was given for 30 minutes, twice a day 5 days a week, for 3 weeks. CG: conventional stroke rehabilitation program was given for 30 minutes twice a day 5 days a week, for 3 weeks.	-The effect of respiratory muscle training on FEV1 (P= 0.027) and peak flow (P=0.004) were statistically significant. The improvement in FVC and also FEV1/FVC, % was not statistically significant between the two groups. (P=0.066), (P=0.607) respectively. -There were no significant differences between the two groups in pulmonary function and stroke-related complications.	- Significant short-term effects of bedside respiratory muscle training in patients with stroke were observed. Much improvement in pulmonary function was reported, but the prophylactic effect of reducing pneumonia was not shown.
de Menezes KKP et al, 2019^Citation17	-38 total participants: EG (n=19), CG (n=19) -Mean age (years): EG (n=60), CG (n=67) Female/male: EG;11/8, CG;11/8 -Duration (months); EG;24±2), CG;16±12 Types of stroke:(ischemic/hemorrhagic/unknown) EG;12/3/4, CG;15/3/1	-MIP -MEP -6m walk test -Endurance inspiratory muscle (no of breaths)	-EG: received high intensity home based respiratory muscle training for 40 min/day, 7 times a week over 8 weeks. -CG: received sham home based respiratory muscle training for 40 min/day, 7 times a week over 8 weeks.	The result showed that significant changes were observed in MIP (P<0.001), MEP (P<. 001) and inspiratory endurance (P<0.001). Significant between-group differences were also found for dyspnea at post-intervention (P<0.01) and follow-up (P<0.05) measures. No significant differences were found in walking capacity P<0.29) and respiratory complications (P=99)	High-intensity home-based respiratory muscle training was effective in increasing strength and endurance of the respiratory muscles and reducing dyspnea for people with stroke.
Guillén-Solà, et al, 2017^Citation18	-62 total participants: SST (n=21), IEMT (n=20), NMES (n=21) -Mean age (years): SST (n=68.9), IEMT (n=67.9), NMES (n=70.3) Female/male: SST;9/12 IEMT;4/16, NMES;11/10 -Duration (days): SST; 9.3± 5.1) IEMT; 10.8± 8.7, NMES; 11.0 ±5.5 -Types of stroke: subacute dysphagic stroke	-Penetration-aspiration scale, -MIP -MEP -Respiratory complication -Dysphagia Outcome Severity Scale -Barthel Index -Modified Rankin scale	-Group I: received SST (3 hours per day, 5 days a week, for 3 weeks) -Group II: received SST & respiratory muscle training, 5 sets of 10 respirations twice a day, 5 days per week for 3 weeks. -Group III: received SST & sham respiratory muscle training for 3 weeks and 80 Hz of transcutaneous electrical stimulus on suprahyoid muscles for 40-minute daily sessions, 5 days per week for 3 weeks.	- inspiratory and expiratory muscle training showed significant improvement in PImax (p=0.015) and PEmax (P=0.044) at 3 week intervention and no significant change was observed at 3 months post-intervention and efficacy signs improved for inspiratory and expiratory muscle training (p=0.037) at 3 months post-intervention.	- Adding IEMT to SST was an effective, feasible, and safe approach that improved respiratory muscle strength. Both IEMT and NMES were associated with improvement in pharyngeal swallowing security signs at the end of the intervention but the effect did not persist at 3-month follow-up and there were no differences in respiratory completions b/n groups.
Messaggi-Sartor, M et al 2015^Citation19	-Total 109 participants: IEMT (n = 56) and sham (n = 53) -Mean age (Years): IEMT (65.6), sham (67.6) Female/male: IEMT;21/35, sham;25/28 -Duration (months): IEMT 9.5±7.8 Sham 8.8 ± 5.1 -Types of stroke: ischemic stroke	-PI max -PE max -Respiratory complication	- EG: received CPT and IEMT of 5 sets of 10 repetitions, twice a day, 5 days per week for 3 weeks duration -CG: received standard multidisciplinary inpatient rehabilitation program 3 hours per day, 5 days a week, for 3 weeks).	-IEMT induced a greater change on PImax (p=0.002) and PEmax (p=0.02) in comparison to the sham group. Respiratory complications were frequently observed in the control group	-IEMT appears to be a useful tool to improve respiratory muscle strength. Fewer respiratory complications at 6 months in the intervention group suggest that IEMT could be considered for inclusion in stroke rehabilitation programs
Britto, R.R et al 2011^Citation20	-Total 18 participants: EG:9, CG:9 -Mean age (years): EG (56.66), CG (51.44) Female/male: EG;4/5, CG;5/4 -Duration (months): not mentioned -Types of stroke: chronic stroke	-MIP - IME -NHP -FVC -FEV1	EG: received home-based training, with resistance adjusted biweekly to 30% of MIP 30 minutes a day 5 times a week for 8 weeks. CG: received home training 30 minutes a day, 5 times a week for 8 Weeks.	-There were significant between-group differences for the MIP and IME measures. Significant changes were observed for only the experimental group for MIP (67.8/14.6) at baseline to 102./26.0cmH2O (at post training) and IME (31.819.3 to 421.1cmH2O). No statistically significant differences were observed in functional performance and QOL.	-IMT training resulted in benefits regarding respiratory muscular performance, determined by increases in respiratory strength and endurance.
Kulnik, S.T et al 2015^Citation21	-Total of 78 participants: (EG1;27), (EG2;26), (CG;25) -Mean age (years): ET (65.7) IT (62.5), Sham:(65.1) Female/male: ET;13/14, IT;9/17, Sham;9/16 -Duration (months): not mentioned -Types of stroke: (ischemic/hemorrhagic); ET22/5, IT;23/3, Sham;24/1	-PECF -PEmax -PImax	-RMT consisted of 5 sets of 10 breaths each with 1-minute rests between sets. Resistance was set at 50% of maximal inspiratory (PImax) or expiratory (PEmax) mouth pressure for inspiratory or expiratory training, respectively.	There were significant improvements in the mean maximal inspiratory (14 cmH2O; P<0.0001) and expiratory (15 cmH2O; P<0.0001) between baseline and 28 days in all groups. There were no between-group differences regarding respiratory muscle training and incidence of pneumonia.	-Respiratory muscle function and cough flow improved with time after acute stroke. Additional inspiratory or expiratory respiratory muscle training does not augment or expedite this improvement.

Abbreviations: BBS, Berg Balance Scale; BI, Barthel Index; BRT, breathing retraining; CG, control group; EG, experimental group; ET, expiratory training; FAC, Functional Ambulation Categories; FEF 25–75%, forced expiratory flow rate 25–75%; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; IG, intervention group; IEMT, inspiratory and expiratory muscle training; IME, inspiratory muscular endurance; IMT, inspiratory muscle training; IT, inspiratory training; MEP, maximum expiratory pressure; MIP, maximum inspiratory pressure; MVV, maximum voluntary ventilation; NHP, Nottingham Health Profile; NMES, neuromuscular electrical stimulation; PECF, peak expiratory cough flow; PEF, peak expiratory flow rate; PEmax, maximal expiratory pressure; PImax, maximal inspiratory pressure; QOL, quality of life; RMTG, respiratory muscle training group; VC, vital capacity; SST, standard swallow therapy.

Table 2 PEdro Scores of Each RCT

No	PEDro Scale Item	Sutbeyaz. ST et al 2010^Citation15	Yoo H-J, Pyun S-B 2018^Citation16	de Menezes KKP et al 2019^Citation17	Guillén-Solà, A et al 2017^Citation18	Messaggi-Sartor, M et al 2015^Citation19	Britto, R.R et al 2011^Citation20	Kulnik, S.T et al 2015^Citation21
1.	Eligibility	YES	YES	YES	YES	YES	YES	YES
2.	Random allocation	YES	YES	YES	YES	YES	YES	YES
3.	Concealed allocation	YES	NO	YES	NO	YES	YES	YES
4.	Baseline comparability	YES	YES	YES	YES	YES	YES	YES
5.	Blind participant	NO	NO	YES	NO	YES	NO	YES
6.	Blind therapist	NO	NO	NO	NO	NO	NO	NO
7.	Blind assessor	YES	NO	NO	YES	YES	YES	YES
8.	Adequate follow up	YES	YES	YES	NO	NO	YES	NO
9.	Intention-to- treat	NO	YES	YES	YES	YES	NO	YES
10.	Between-group comparison	YES	YES	YES	YES	YES	YES	YES
11.	Point estimate and variability	YES	YES	YES	YES	YES	YES	YES
	Total score	7/10	6/10	8/10	6/10	8/10	7/10	8/10

Figure 1 PRISMA diagram of effectiveness of respiratory muscle training in patients with stroke.

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Yoo H-J, Pyun S-B. Efficacy of bedside respiratory muscle training in patients with stroke: a randomized controlled trial. Am J Phys Med Rehabil. 2018;97(10):691–697. doi:10.1097/PHM.0000000000000933

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