Effects of different respiratory training methods on respiratory function in patients with spinal cord injury: a network meta-analysis of randomized controlled trials.

Objective: This network meta-analysis (NMA) compared the efficacy of various respiratory training methods in improving respiratory function in patients with spinal cord injury (SCI).

Methods: Randomized controlled trials (RCTs) on respiratory training interventions for SCI patients were searched in PubMed, Embase, Web of Science, and the Cochrane Library through September 1, 2024. The risk of bias in the included studies was assessed using the Cochrane tool. Review Manager 5.4 was used to conduct a systematic review using Bayesian NMA methods. The Confidence in Network Meta-Analysis (CINeMA) framework was employed to evaluate the quality of evidence. The primary outcomes were maximal inspiratory pressure (MIP), forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC).

Results: Seventeen RCTs (n = 625) were included, evaluating eight respiratory training interventions and one control intervention. NMA revealed that for improving MIP, transcutaneous spinal cord stimulation plus resistance respiratory muscle training (tSCS_RRMT) (SUCRA 86.32%) showed the greatest efficacy, followed by resistance respiratory muscle training (RRMT) (SUCRA 84.09%). For FEV1, repetitive functional magnetic stimulation combined with abdominal neuromuscular electrical stimulation and routine breathing training (rFMS_NMES_RBT) (SUCRA 89.41%) demonstrated superior efficacy, followed by incentive spirometry combined with the abdominal drawing-in maneuver (IS_ADIM) (SUCRA 70.05%). For FVC, IS_ADIM (SUCRA 76.25%) was most effective, followed by routine breathing training (RBT) (SUCRA 65.40%). League table results indicated that RRMT (mean difference (MD) 13.25, 95% credible intervals (CrI) [7.51, 18.92]) significantly improved MIP compared to the control intervention; IS_ADIM (MD 0.58, 95% CrI [0.31, 0.85]) and RBT (MD 0.49, 95% CrI [0.29, 0.69]) enhanced FVC compared to the control intervention.

Conclusion: tSCS_RRMT appears to be the most effective for improving MIP, rFMS_NMES_RBT for enhancing FEV1, and IS_ADIM for improving FVC based on SUCRA rankings. Due to irreconcilable heterogeneity, indirectness, imprecision, and incoherence, the reliability of the evidence is limited.

Trial Registration: This network meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was prospectively registered in PROSPERO (CRD42024592511).