Comparing two types of loading during inspiratory muscle training in patients with weaning difficulties: An exploratory study.

BACKGROUND: Inspiratory muscle training improves respiratory muscle function and may improve weaning outcomes in patients with weaning difficulties. Compared to the commonly used pressure threshold loading, tapered flow resistive loading better accommodates pressure-volume relationships of the respiratory muscles, which might help to facilitate application of external loads and optimise training responses. OBJECTIVE: The objective of this study was to compare acute breathing pattern responses and perceived symptoms during an inspiratory muscle training session performed against identical external loading provided as pressure threshold loading or as tapered flow resistive loading. We hypothesised that for a given loading, tapered flow resistive loading would allow larger volume expansion and higher inspiratory flow responses and consequently higher external work of breathing and power than pressure threshold loading and that subsequently patients perceived fewer symptoms during tapered flow resistive loading than during pressure threshold loading. METHODS: In this exploratory study, 21 patients (maximal inspiratory pressure: 35 ± 14 cmH2O and vital capacity:0.85 L±0.37 L) performed two training sessions against external loads equalling 42 ± 15% of maximal inspiratory pressure provided either as pressure threshold loading or as tapered flow resistive loading. During these training sessions, breath-by-breath data of breathing parameters were collected, and patients rated their perceived breathing effort, dyspnoea, and unpleasantness. RESULTS: Compared to pressure threshold loading, tapered flow resistive loading allowed significantly larger volume expansion (0.53 ± 0.28 L versus 0.41 ± 0.20 L, p < 0.01) and inspiratory flow responses (0.43 ± 0.20 L/s versus 0.33 ± 0.16 L/s, p = 0.01). Tapered flow resistive loading was perceived as less unpleasant (3.1 ± 1.9 versus 3.8 ± 2.4, p = 0.048). No significant differences in breathing effort, dyspnoea, work of breathing, and power were observed. CONCLUSIONS: For a given loading, inspiratory muscle training with tapered flow resistive loading allowed larger volume expansion and higher inspiratory flow responses than pressure threshold loading, which led patients to perceive tapered flow resistive loading as less unpleasant. This might help us to facilitate early implementation of inspiratory muscle training in patients with weaning difficulties. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov identifier: NCT03240263.

[Efficacy of Physiotherapy Interventions on the Respiratory Musculature Through Respiratory Training Techniques in Post-operative Lung Transplant Recipients: Systematic Review]. / Eficacia de las intervenciones fisioterápicas sobre la musculatura respiratoria mediante técnicas de entrenamiento respiratorio en el postoperatorio de trasplantados pulmonares: una revisión sistemática.

Introduction: Respiratory muscles are a limiter of exercise capacity in lung transplant patients. It is necessary to know the effectiveness of specific respiratory muscle training techniques carried out in the management of adult lung transplant patients in the postoperative period. Methodology: A systematic review of clinical trials was carried out, which included adult lung transplant patients undergoing post-transplant respiratory training. A search was carried out in the databases PubMed/Medline, EMBASE, Scopus, Web of Science, Cochrane Library between January 2012 and September 2023, using the terms: "breathing exercise", "respiratory muscle training", "inspiratory muscle training", "respiratory exercise", "pulmonary rehabilitation", "lung rehabilitation"; in combination with "lung transplantation", "lung transplant", "posttransplant lung". No language limit. Results: Eleven trials were included with a total of 639 patients analyzed. Most training programs begin upon hospital discharge (more than one month post-transplant), few do so early (Intensive Care Unit). The duration varies from 1-12 months post-transplant. The interventions were based on aerobic training and peripheral muscle strength. Some of them included breathing exercises and chest expansions. The most used outcome variable was submaximal exercise capacity measured with the 6-minute walk test. Conclusions: Training the respiratory muscles of the adult transplant patient favors the improvement of exercise capacity and quality of life. Aerobic training, as well as strength training of the rest of the peripheral muscles, contribute to the improvement of respiratory muscles.