Diaphragm stimulation in critically ill patients: what do we know, and what do we still need to learn?

Pennone, Julia Machado da Costa; Batista, Carolina Pereira; Polloni, Giulia Alves Salustiano; Bueno, Marina Brunelli Ferreira; Britto, Angélica Cristiane da Cruz; Nawa, Ricardo Kenji; Mól, Caroline Gomes

doi:10.31744/einstein_journal/2026CE2373

Dear Editor,

Diaphragm weakness is a common complication in critically ill patients and can develop within days after the initiation of invasive mechanical ventilation.(¹,²) It is characterized by a rapid loss of diaphragm contractile capacity, which compromises the patient's ability to breathe independently.(¹,²) Diaphragm weakness is strongly associated with worse clinical outcomes, including prolonged weaning from mechanical ventilation (MV), longer intensive care unit (ICU) and hospital length of stay, and higher mortality.(¹-⁴) Because of its high prevalence and major clinical impact, substantial efforts have focused on identifying strategies and interventions to prevent or reverse diaphragm weakness and dysfunction, such as inspiratory muscle training, early mobilization, and diaphragm electrical stimulation.(⁵-⁸)

In this context, neuromuscular stimulation has emerged as a promising strategy to preserve or restore diaphragmatic function in critically ill patients, either through direct stimulation of the diaphragm muscle or by stimulating the phrenic nerve, which innervates the diaphragm.(⁶,⁹) The rationale behind these techniques is to preserve diaphragm activity during MV, thereby limiting disuse atrophy and contractile dysfunction. Transcutaneous stimulation is commonly described as the application of electrical stimuli through surface electrodes placed on the thoracoabdominal region to directly recruit the diaphragm at the zone of apposition, where it lies closer to the body surface.(⁶,¹⁰,¹¹) Another non-invasive approach involves cervical stimulation using surface or pen electrodes along the course of the phrenic nerve to indirectly activate the diaphragm.(⁹) Invasive approaches, including intramuscular diaphragmatic pacing and transvenous phrenic nerve stimulation, have also been investigated and may provide more targeted and sustained stimulation; however, their implementation in clinical practice is associated with greater procedural complexity.(⁶,¹²)

To date, the available evidence indicates that diaphragm stimulation is feasible and generally safe, with preliminary studies suggesting potential benefits such as shorter duration of MV, reduced ICU length of stay, and improved success of ventilator weaning in patients requiring prolonged MV.(⁶,⁹-¹²) However, most of these data come from small and methodologically heterogeneous studies, which limits the strength and generalizability of these findings. As a result, although diaphragm stimulation appears to be a promising strategy for preventing and treating diaphragm dysfunction in critically ill patients, its role in routine clinical practice and its true impact on patient-centered outcomes remains insufficiently established. Despite the growing body of evidence supporting diaphragmatic stimulation in critically ill patients, important knowledge gaps remain. These include identifying which patient populations are most likely to benefit and comparing the effectiveness of direct diaphragmatic versus phrenic nerve stimulation, defining optimal stimulation parameters, and establishing how best to integrate these interventions into standard respiratory and rehabilitation protocols.

The impact of diaphragmatic stimulation on clinically meaningful short- and long-term outcomes remains poorly defined. Well-designed, prospective clinical trials are therefore needed to clarify the therapeutic value of diaphragmatic stimulation and to support the development of evidence-based guidelines for its implementation in ICUs worldwide.

DATA AVAILABLE

The underlying content is contained within the manuscript.

REFERENCES

¹ Supinski GS, Morris PE, Dhar S, Callahan LM. Diaphragm dysfunction in critical illness. Chest. 2018;153(4):1040-51.
² Dres M, Goligher EC, Heunks LM, Brochard LJ. Critical illness-associated diaphragm weakness. Intensive Care Med. 2017;43(10):1441-52.
³ Demoule A, Molinari N, Jung B, Prodanovic H, Chanques G, Matecki S, et al. Patterns of diaphragm function in critically ill patients receiving prolonged mechanical ventilation: a prospective longitudinal study. Ann Intensive Care. 2016;6(1):75.
⁴ Dres M, Jung B, Molinari N, Manna F, Dubé BP, Chanques G, et al. Respective contribution of intensive care unit-acquired limb muscle and severe diaphragm weakness on weaning outcome and mortality: a post hoc analysis of two cohorts. Crit Care. 2019;23(1):370.
⁵ Eggmann S, Parry SM, Broadley T, Lynch GS, Bongetti AJ, Ridley EJ, et al. The intensive care medicine research agenda for the management of ICU acquired weakness: a multinational, interprofessional perspective. Intensive Care Med. 2025;51(12):2199-212.
⁶ Tong S, Yang Y, Li Y, Liu L, Chang W. Consequences in critically ill patients with prolonged mechanical ventilation after diaphragmatic stimulation techniques: a systematic review and meta-analysis. BMJ Open. 2025;15(9):e098814.
⁷ Chagas GR, Vieira AG, Araújo JC, Eid RA, Mól CG, Nawa RK. Inspiratory muscle training for chronic critically ill patients: a systematic review and meta-analysis of randomized controlled trials. einstein (São Paulo). 2025;23:eRW1134.
⁸ McCormack E, McDonough S, Kelly YP, Baily-Scanlan M, Holden N, Hammond L, et al. What is the effect of measurable respiratory muscle training on respiratory muscle strength in mechanically ventilated adults in intensive care units? A systematic review and meta-analysis. Aust Crit Care. 2025;38(6):101418.
⁹ Soták M, Roubík K, Henlín T, Tyll T. Phrenic nerve stimulation prevents diaphragm atrophy in patients with respiratory failure on mechanical ventilation. BMC Pulm Med. 2021;21(1):314.
¹⁰ Medrinal C, Machefert M, Lamia B, Bonnevie T, Gravier FE, Hilfiker R, et al. Transcutaneous electrical diaphragmatic stimulation in mechanically ventilated patients: a randomised study. Crit Care. 2023;27(1):338.
¹¹ Leite MA, Osaku EF, Albert J, Costa CR, Garcia AM, Czapiesvski FN, et al. Effects of neuromuscular electrical stimulation of the quadriceps and diaphragm in critically ill patients: a pilot study. Crit Care Res Pract. 2018;2018:4298583.
¹² Dres M, Ewert R, Conrad SA, Ataya A, Shrager J, Mortaza S, Delamaire F, Nilius G, Heine A, Mehta N, Ways J, Evans D, Paulon G, Khandwala F, Berry N, Viele K, Nelson T, Gilbertson M, Similowski T, Gama de Abreu M, Goligher EC; RESCUE-3 Trial Investigators. Temporary Transvenous Diaphragm Neurostimulation for Weaning from Mechanical Ventilation (RESCUE-3). Am J Respir Crit Care Med. 2025 Jun 11.

Associate Editor:
Kenneth Gollob Hospital Israelita Albert Einstein, São Paulo, SP, Brazil ORCID: https://orcid.org/0000-0003-4184-3867

Publication Dates

Publication in this collection
26 June 2026
Date of issue
2026

History

Received
09 Jan 2026
Accepted
22 Feb 2026

This content is licensed under a Creative Commons Attribution 4.0 International License.

[1] ¹ Supinski GS, Morris PE, Dhar S, Callahan LM. Diaphragm dysfunction in critical illness. Chest. 2018;153(4):1040-51.

[2] ² Dres M, Goligher EC, Heunks LM, Brochard LJ. Critical illness-associated diaphragm weakness. Intensive Care Med. 2017;43(10):1441-52.

[3] ³ Demoule A, Molinari N, Jung B, Prodanovic H, Chanques G, Matecki S, et al. Patterns of diaphragm function in critically ill patients receiving prolonged mechanical ventilation: a prospective longitudinal study. Ann Intensive Care. 2016;6(1):75.

[4] ⁴ Dres M, Jung B, Molinari N, Manna F, Dubé BP, Chanques G, et al. Respective contribution of intensive care unit-acquired limb muscle and severe diaphragm weakness on weaning outcome and mortality: a post hoc analysis of two cohorts. Crit Care. 2019;23(1):370.

[5] ⁵ Eggmann S, Parry SM, Broadley T, Lynch GS, Bongetti AJ, Ridley EJ, et al. The intensive care medicine research agenda for the management of ICU acquired weakness: a multinational, interprofessional perspective. Intensive Care Med. 2025;51(12):2199-212.

[6] ⁶ Tong S, Yang Y, Li Y, Liu L, Chang W. Consequences in critically ill patients with prolonged mechanical ventilation after diaphragmatic stimulation techniques: a systematic review and meta-analysis. BMJ Open. 2025;15(9):e098814.

[7] ⁷ Chagas GR, Vieira AG, Araújo JC, Eid RA, Mól CG, Nawa RK. Inspiratory muscle training for chronic critically ill patients: a systematic review and meta-analysis of randomized controlled trials. einstein (São Paulo). 2025;23:eRW1134.

[8] ⁸ McCormack E, McDonough S, Kelly YP, Baily-Scanlan M, Holden N, Hammond L, et al. What is the effect of measurable respiratory muscle training on respiratory muscle strength in mechanically ventilated adults in intensive care units? A systematic review and meta-analysis. Aust Crit Care. 2025;38(6):101418.

[9] ⁹ Soták M, Roubík K, Henlín T, Tyll T. Phrenic nerve stimulation prevents diaphragm atrophy in patients with respiratory failure on mechanical ventilation. BMC Pulm Med. 2021;21(1):314.

[10] ¹⁰ Medrinal C, Machefert M, Lamia B, Bonnevie T, Gravier FE, Hilfiker R, et al. Transcutaneous electrical diaphragmatic stimulation in mechanically ventilated patients: a randomised study. Crit Care. 2023;27(1):338.

[11] ¹¹ Leite MA, Osaku EF, Albert J, Costa CR, Garcia AM, Czapiesvski FN, et al. Effects of neuromuscular electrical stimulation of the quadriceps and diaphragm in critically ill patients: a pilot study. Crit Care Res Pract. 2018;2018:4298583.

[12] ¹² Dres M, Ewert R, Conrad SA, Ataya A, Shrager J, Mortaza S, Delamaire F, Nilius G, Heine A, Mehta N, Ways J, Evans D, Paulon G, Khandwala F, Berry N, Viele K, Nelson T, Gilbertson M, Similowski T, Gama de Abreu M, Goligher EC; RESCUE-3 Trial Investigators. Temporary Transvenous Diaphragm Neurostimulation for Weaning from Mechanical Ventilation (RESCUE-3). Am J Respir Crit Care Med. 2025 Jun 11.