Effectiveness of Respiratory Muscle Training in Adults With Pulmonary Hypertension. A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with pulmonary hypertension (PH) may have impaired exercise capacity and quality of life; this may possibly be due to the early onset of dyspnoea associated with respiratory muscle weakness. Respiratory muscle training could improve the condition of these patients, so this study aimed to determine, through a systematic review and meta-analysis, the effectiveness of respiratory muscle training in adult patients with PH. METHODS: Medline, Embase, CENTRAL, clinical trial registries databases, and grey literature and reference lists of reviews related to the objective were searched up to March 2022. Controlled clinical trials comparing the effectiveness of respiratory muscle training with sham or no intervention in adults with PH were included. Records were independently screened by two authors. The primary outcomes were maximal and functional exercise capacity, quality of life, and dyspnoea. The secondary outcomes were respiratory muscle strength, physical activity, lung function, and adverse events. Two authors independently extracted data and the study quality was assessed using the Cochrane risk-of-bias tool 2 (RoB 2). The certainty of the evidence was assessed according to the GRADE approach. RESULTS: A total of 5,524 records were screened, and seven randomised clinical trials (RCTs) (257 participants) were included. It was uncertain whether inspiratory muscle training (IMT), compared with sham IMT or no intervention, increased the distance walked in the 6-minute walk test (6MWT) (MD, 39 m; 95% CI, 20.72-57.39; I2=27%; four RCTs; very low certainty of evidence) and slightly decreased the perceived sensation of dyspnoea (MD, 0.5 points on the mMRC scale; 95% CI, -0.87 to -0.13; I2=0%; two RCTs; very low certainty of evidence). In addition, it was uncertain whether IMT had no effect on the emotional (SMD, -0.34; 95% CI, -1.06 to 0.38; I2=64%; three RCTs; very low certainty of evidence) and physical (SMD, 0.06; 95% CI, -0.41 to 0.52; I2=16%; three RCTs; very low certainty of evidence) component of quality of life. CONCLUSIONS: It is uncertain whether IMT increases functional exercise capacity and slightly decreases the sensation of dyspnoea. In addition, it is uncertain whether IMT does not affect the quality of life. More RCTs and with a better methodological design are needed to increase the certainty of the evidence and determine the real effect of this intervention.

Entrenamiento de la musculatura respiratoria en adultos con hipertensión pulmonar. Protocolo de una revisión sistemática y meta-análisis / Respiratory muscle training in adults with pulmonary hypertension. Protocol of a systematic review and meta-analysis

Introducción: Se ha demostrado que pacientes con hipertensión pulmonar presentan debilidad de la musculatura respiratoria, lo que se asocia a una baja tolerancia al ejercicio físico. El entrenamiento de la musculatura respiratoria podría incrementar su función, lo que podría impactar en menor disnea, aumento de la capacidad de realizar ejercicio y calidad de vida. Objetivos: Estimar los efectos del entrenamiento de la musculatura respiratoria en adultos con hipertensión pulmonar. Métodos: Se realizará una revisión sistemática y meta-análisis de ensayos clínicos controlados, aleatorizados y no aleatorizados. Se incluirán estudios sin restricción por fecha, estado de publicación, ni idioma, y publicados en revistas científicas, en actas de congresos o literatura gris, que incluyan pacientes adultos con hipertensión pulmonar (grupos I, II, IV y IV de la clasificación de la Organización Mundial de la Salud), que consideren como intervención el entrenamiento de la musculatura respiratoria, y que reporten al menos un desenlace clínicamente relevante. La búsqueda se realizará en las bases de datos MEDLINE, Embase y CENTRAL, y en otros recursos de búsqueda. La selección de estudios, extracción de datos, valoración del riesgo de sesgo, evaluada mediante la escala del riesgo de sesgo Cochrane, y la valoración de la certeza de la evidencia, evaluada mediante el enfoque GRADE, se realizará por duplicado y de manera independiente. Las discrepancias se resolverán por consenso u otro revisor. Los resultados se describirán cualitativa y cuantitativamente, y los meta-análisis se realizarán mediante modelo de efectos aleatorios y se estimará la presencia de sesgo de reporte.

Background: It has been shown that patients with pulmonary hypertension present weakness of the respiratory musculature, which is associated with a low tolerance to physical exercise. Training of the respiratory muscles may increase their function, which may impact decreased dyspnea, increased exercise capacity and quality of life. Objectives: Estimate the effects of training the respiratory muscle in adults with pulmonary hypertension. Methods: A systematic review and meta-analysis of controlled clinical trials, randomized and non-randomized, will be conducted. Studies will be included without restriction by date, state of publication, or language, and published in scientific journals, in congress proceedings or grey literature, that include adult patients with pulmonary hypertension (groups I, II, IV and IV of the World Health Organization classification), which consider respiratory muscle training as an intervention, and which report at least one clinically relevant outcome. The search will be performed on the MEDLINE, Embase, and CENTRAL databases and other search resources. Study selection, data extraction, risk of bias assessment, as assessed by the Cochrane Risk of Bias scale, and certainty of evidence assessment, as assessed by the GRADE approach, will be performed in duplicate and independently. Discrepancies will be resolved by consensus or another reviewer. Results will be described qualitatively and quantitatively, and meta-analyses will be performed using a random-effects model and the presence of reporting bias will be estimated.