Comparative effectiveness of inspiratory muscle training approaches within intensive care unit–acquired weakness prevention and rehabilitation strategies: a systematic review and component network meta-analysis

OBJECTIVE: This study compared the relative effectiveness of different inspiratory muscle training (IMT) modalities within intensive care unit-acquired weakness (ICU-AW) prevention and rehabilitation strategies using network meta-analysis (NMA) and component network meta-analysis (CNMA). METHODS: A systematic search of electronic databases in both Chinese and English was conducted to identify randomized controlled trials (RCTs) enrolling adult patients (≥ 18 years) admitted to the intensive care unit (ICU). Eligible studies evaluated strategies for the prevention and rehabilitation of ICU-AW, including inspiratory muscle training IMT-related interventions, systemic physical rehabilitation, and their combinations. The Cochrane Risk of Bias 2 (RoB2) tool was used to assess the risk of bias in the included RCTs, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was applied to evaluate the quality of the evidence. Heterogeneity was initially assessed using conventional pooled analyses and was not used as the sole criterion for model selection in the subsequent NMA. Outcomes with substantial heterogeneity were further analyzed using random-effects NMA, for which 95% prediction intervals (PIs) were additionally reported. For outcomes with low apparent heterogeneity, fixed-effect NMA was applied, with heterogeneity interpreted in light of clinical and methodological diversity across studies. Component network meta-analysis (CNMA) was additionally conducted to quantify the independent treatment effect of each intervention component. For continuous outcome measures (Medical Research Council [MRC] score, maximal inspiratory pressure [MIP], and duration of mechanical ventilation [MV]), results were presented as mean differences (MDs) and their 95% confidence intervals (CIs). For binary outcome measures (incidence of ICU-AW and weaning success rate), treatment effects were expressed as odds ratios (ORs) with 95% CIs. RESULTS: A total of 23 eligible randomized controlled trials (RCTs) were included in this analysis, which evaluated 11 distinct intervention strategies. These strategies were categorized into 5 multicomponent interventions and 6 single-component interventions. The 6 single-component interventions included 4 IMT modalities, a systemic physical rehabilitation intervention, and routine care, which was designated as the reference control group. Compared with the routine care reference group, mechanical threshold showed a non-statistically significant trend toward lower ICU-AW incidence (OR = 0.19, 95% CI [0.04, 1.01]); hence, the best-ranked results based on SUCRA should be interpreted as exploratory findings only. The combination of systemic physical rehabilitation and routine inspiratory muscle training was associated with improved MRC scores and higher weaning success rates. For MIP, the combination of systemic physical rehabilitation and mechanical threshold achieved the highest ranking. CNMA further indicated that the addition of systemic physical rehabilitation to mechanical threshold was associated with incremental therapeutic benefit. For duration of MV, combined strategies incorporating systemic physical rehabilitation and IMT also ranked favorably; however, this outcome was associated with a higher degree of uncertainty and should be interpreted with caution. According to the GRADE approach, the certainty of evidence was rated as low for the incidence of ICU-AW, moderate for the MRC score, weaning success rate, and MIP, and very low for the duration of mechanical ventilation. CONCLUSION: While combined interventions incorporating systemic physical rehabilitation and IMT ranked highest across multiple outcomes, evidence supporting the superiority of any specific IMT regimen over another remains limited. For MIP, CNMA further demonstrated that the addition of systemic physical rehabilitation to mechanical threshold was associated with a statistically significant incremental therapeutic benefit compared with mechanical threshold alone, although definitive isolation of the independent effects of most individual components was not possible. Overall, these findings provide a more differentiated assessment of IMT-related strategies within ICU-AW prevention and rehabilitation. However, the overall certainty of evidence ranged from moderate to very low across all outcomes according to the GRADE framework, highlighting the need for further high-quality randomized controlled trials to validate these findings. This systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD420251208302.