Diego Poddighe

This corrects the article 10.3791/70146.

Inspiratory muscle weakness is common among mechanically ventilated patients and is a well-recognized contributor to weaning difficulties, which are associated with poor outcomes and increased mortality. Inspiratory muscle training is a feasible and promising intervention that can improve global respiratory muscle strength and potentially facilitate successful liberation from mechanical ventilation in patients with weaning difficulties. This article proposes a practical guide supporting clinicians in integrating inspiratory muscle training into the care of mechanically ventilated patients experiencing weaning difficulties, informed by clinical experience and current evidence. The proposed approach focuses on the application of inspiratory muscle training in patients with weaning difficulties (mostly tracheostomized patients undergoing prolonged weaning), who fulfill readiness-to-wean criteria and are fully cooperative. Training sessions are typically conducted daily while the patient is disconnected from the ventilator, following an initial assessment of maximal inspiratory pressure and forced vital capacity. These parameters, along with volume displacement observed during each training session and symptom scores evaluated afterward, are used to individualize the initial external load and training progression. The main components that are taken into account to offer and individualize the training approach include patient selection, respiratory muscle and lung function assessment, load setting modalities, breathing instructions during training, and training progression guided by symptom scores and volume displacement.

Inspiratory muscle weakness is common among mechanically ventilated patients and is a well-recognized contributor to weaning difficulties, which are associated with poor outcomes and increased mortality. Inspiratory muscle training is a feasible and promising intervention that can improve global respiratory muscle strength and potentially facilitate successful liberation from mechanical ventilation in patients with weaning difficulties. This article proposes a practical guide supporting clinicians in integrating inspiratory muscle training into the care of mechanically ventilated patients experiencing weaning difficulties, informed by clinical experience and current evidence. The proposed approach focuses on the application of inspiratory muscle training in patients with weaning difficulties (mostly tracheostomized patients undergoing prolonged weaning), who fulfill readiness-to-wean criteria and are fully cooperative. Training sessions are typically conducted daily while the patient is disconnected from the ventilator, following an initial assessment of maximal inspiratory pressure and forced vital capacity. These parameters, along with volume displacement observed during each training session and symptom scores evaluated afterward, are used to individualize the initial external load and training progression. The main components that are taken into account to offer and individualize the training approach include patient selection, respiratory muscle and lung function assessment, load setting modalities, breathing instructions during training, and training progression guided by symptom scores and volume displacement.

We thank H. Zhao and co-workers for their interest in our review [1] and appreciate their considerations for enhancing the utility of diaphragmatic ultrasound. Our work [1] was based on recent systematic reviews and task force statements [2–5], in which diaphragm dysfunction was typically defined by a diaphragm thickening fraction (DTF) <20%. H. Zhao and co-workers describe two situations in which DTF and diaphragm excursion (DE) may show opposing changes and propose using some alternative ultrasound techniques in these scenarios. We would like to briefly share a few considerations regarding the presented situations and proposed alternative techniques.

Rationale: Inspiratory muscle training (IMT) improves respiratory muscle function in patients with weaning difficulties. IMT protocols involve performing daily sets of breaths against external loads. However, the impact of IMT on weaning outcomes while incorporating sham control interventions remains unclear. Objectives: To compare the effects of a high-intensity IMT (Hi-IMT) intervention with a sham low-intensity (Lo-IMT) control group on weaning outcomes and respiratory muscle and pulmonary function 28 days after inclusion in patients with weaning difficulties. Methods: Both groups underwent daily IMT sessions until successful weaning or a maximum of 28 days. The Hi-IMT group (n = 44; 61% male; aged 57 ± 15 yr) performed maximal inspirations initiated from residual volume against an external load representing 30–50% of maximal inspiratory pressure (PImax), and the control group (n = 46; 52% male; aged 60 ± 12 yr) performed maximal inspirations against a load ⩽10% PImax. Measurements and Main Results: Training adherence (completed/planned sessions) was comparable between the groups (Hi-IMT, 77 ± 20%; Lo-IMT, 72 ± 17%; P = 0.25). Weaning success (64% Hi-IMT and 76% Lo-IMT; P = 0.43) and weaning duration (Hi-IMT, 45 ± 48 d; Lo-IMT, 37 ± 26 d; P = 0.33) were similar between groups. Both groups similarly improved PImax (Hi-IMT, +15 cm H2O [95% confidence interval (CI), 9, 20]; Lo-IMT, +14 cm H2O [95% CI, 9, 19]; P = 0.72). FVC improved more in the Hi-IMT group than in the Lo-IMT group (Hi-IMT, +0.33 L [95% CI, 0.22, 0.43]; Lo-IMT, +0.16 L [95% CI, 0.07, 0.25]; P = 0.04). Conclusions: Both high-intensity IMT and sham low-intensity IMT, with high adherence to the protocol, resulted in similar weaning success rates and pronounced improvements in maximal inspiratory muscle strength. Clinical trial registered with www.clinicaltrials.gov (NCT03240263).

Assessing and treating respiratory muscle dysfunction is crucial for patients with both acute and chronic respiratory failure. Respiratory muscle dysfunction can contribute to the onset of respiratory failure and may also worsen due to interventions aimed at treatment. Evaluating respiratory muscle function is particularly valuable for diagnosing, phenotyping and assessing treatment efficacy in these patients. This review outlines established methods, such as measuring respiratory pressures, and explores novel techniques, including respiratory muscle neurophysiology assessments using electromyography and imaging with ultrasound.Additionally, we review various treatment strategies designed to support and alleviate the burden on overworked respiratory muscles or to enhance their capacity through training interventions. These strategies range from invasive and noninvasive mechanical ventilation approaches to specialised respiratory muscle training programmes. By summarising both established techniques and recent methodological advancements, this review aims to provide a comprehensive overview of the tools available in clinical practice for evaluating and treating respiratory muscle dysfunction. Our goal is to present a clear understanding of the current capabilities and limitations of these diagnostic and therapeutic approaches. Integrating advanced diagnostic methods and innovative treatment strategies should help improve patient management and outcomes. This comprehensive review serves as a resource for clinicians, equipping them with the necessary knowledge to effectively diagnose and treat respiratory muscle dysfunction in both acute and chronic respiratory failure scenarios.

Background: The overall diagnostic accuracy(DA) of respiratory muscle assessments to predict weaning outcomes is under debate. Aims: To summarize and compare the DA of diaphragm thickening fraction(DTF), excursion(DE), end-expiratory (Tdiee) and end-inspiratory (Tdiei) thickness, maximal inspiratory pressure (MIP), airway occlusion pressure(P0.1) to predict weaning success (WS) in ICU patients. Methods: Pubmed, EMBASE, WoS, Cochrane Library, CINAHL were searched. Hierarchical summary receiver operating characteristic model was used to estimate the summary receiver operating characteristic (SROC) curves of each assessment. Meta-regression was used to compare SROC curves. SA were performed, excluding studies with potential high risk of bias, assessed with QUADAS-2 tool. Results: 77 studies were meta-analyzed on DTF(n=44), DE(n=40), MIP(n=16), P0.1(n=14), Tdiee(n=9) and Tdiei(n=7). DA was not different between assessments (p>0.05)(Fig.1A). By considering the studies retained in the SA, DA of DTF was significantly higher than for DE(p=0.005). The apparent superiority of DTF on MIP was not statistically significant(p=0.08)(Fig.1B). At 80% specificity, the estimated sensitivity to predict WS was 80% for DTF, 76% for DE and 61% for MIP. Conclusion: DTF seems to have superior DA compared to DE to predict WS, based on a subgroup of good quality studies.