The Clinical Utility of Surface Electromyography in Assessing Respiratory and Accessory Muscles as Predictors of Respiratory Failure: A Comprehensive Review

Surface electromyography (sEMG) has emerged as a non-invasive modality for assessing respiratory muscle activity, including both primary and accessory muscles involved in breathing. Increasing evidence suggests that sEMG-derived indices—such as neural respiratory drive (NRD), muscle recruitment patterns, and fatigue signatures—may serve as biomarkers for respiratory failure, disease severity, and mortality risk across diverse clinical specialties. This review synthesizes current literature on the physiological basis, technical considerations, and clinical applications of sEMG in respiratory medicine, with a particular focus on its prognostic value. We examine its role in acute respiratory failure, chronic obstructive pulmonary disease (COPD), neuromuscular disorders, and critical care settings, including mechanical ventilation and weaning. Particular emphasis is placed on accessory muscle activity as a surrogate for respiratory load-capacity imbalance and its implications for clinical outcomes. Despite promising associations between sEMG signals and outcomes such as dyspnea, ventilatory failure, and mortality, limitations in standardization and interpretation remain barriers to clinical implementation. Future directions include integration with multimodal monitoring and predictive modeling.