Clinical bottom line
Neuromuscular electrical stimulation (NMES) is a promising adjunctive therapy for mitigating muscle weakness in patients with intensive care unit-acquired weakness (ICU-AW). Emerging evidence suggests NMES may improve muscle strength and functional outcomes when applied early and systematically during ICU stays. However, current data remain preliminary, with variable protocols and modest effect sizes. NMES should be considered as part of a multimodal rehabilitation strategy but warrants further validation in larger, well-controlled trials before routine clinical adoption.
What the evidence shows
ICU-acquired weakness is a common and debilitating complication of critical illness, characterized by profound skeletal muscle atrophy and impaired neuromuscular function, leading to prolonged disability and reduced quality of life (Latronico et al., 2014). Conventional rehabilitation is often limited by patient sedation, delirium, and medical instability. NMES offers a non-volitional method to activate muscle fibers and potentially counteract disuse atrophy.
A recent meta-analysis by Liu et al. (2020) synthesized data from randomized controlled trials evaluating NMES interventions in ICU patients with or at risk for ICU-AW. The analysis demonstrated a statistically significant improvement in muscle strength compared to standard care, although effect sizes were modest and heterogeneity across studies was notable. Similarly, Kusumawardani et al. (2019) reviewed the role of NMES in ICU rehabilitation, highlighting its safety and feasibility, with preliminary signals of improved muscle mass preservation and functional recovery.
Harford et al. (2023) conducted a safety study of an electrical muscle stimulation system specifically designed to mitigate ICU-AW, confirming tolerability and absence of adverse events in critically ill patients. Brandenberger et al. (2021) further demonstrated feasibility of an NMES protocol for early detection and intervention in ICU-AW, supporting integration into ICU care pathways.
The DETECT observational study (Machefert et al., 2024) combined early ultrasound muscle measurements with NMES to enhance diagnostic accuracy for ICU-AW, indicating potential for NMES not only as therapy but also as a diagnostic adjunct.
Collectively, these studies suggest NMES can be safely implemented in ICU settings and may improve muscle strength outcomes, but optimal timing, dosing, and patient selection remain to be defined.
Caveats and uncertainty
Despite encouraging findings, several limitations temper enthusiasm for widespread NMES use in ICU-AW:
- Most trials to date have small sample sizes and variable NMES protocols, limiting generalizability (Liu et al., 2020; Kusumawardani et al., 2019).
- Heterogeneity in patient populations, illness severity, and outcome measures complicates interpretation.
- Long-term functional and quality-of-life benefits remain unclear, with few studies extending follow-up beyond ICU discharge (Latronico et al., 2014).
- NMES efficacy may be influenced by factors such as electrode placement, stimulation parameters, and concurrent therapies, which are inconsistently reported.
- The role of NMES in patients with advanced disease or multiple comorbidities is less well studied (Cochrane Clinical Answers, 2017).
Therefore, NMES should be considered an adjunct rather than a standalone intervention, and clinical decisions should be individualized.
How this may change practice
For physical medicine and rehabilitation clinicians managing ICU survivors, NMES represents a potentially valuable tool to incorporate into early rehabilitation protocols aimed at preserving muscle function. Its non-invasive nature and safety profile support feasibility in critically ill patients who cannot actively participate in conventional therapy.
Clinicians should remain cautious, applying NMES within multidisciplinary frameworks and monitoring for patient tolerance and response. Early muscle ultrasound assessment combined with NMES, as explored in the DETECT study, may enhance identification of patients most likely to benefit.
Future practice may evolve toward standardized NMES protocols integrated with mobilization and nutritional optimization to improve long-term recovery trajectories. Until more definitive evidence emerges, NMES use should be guided by institutional protocols and clinical judgment, with ongoing evaluation of outcomes.