Efficacy of external diaphragm pacing combined with high-flow oxygen via tracheostomy for weaning in patients requiring prolonged mechanical ventilation: a study protocol for a randomized controlled trial

Abstract Background Prolonged mechanical ventilation (PMV)—commonly defined as requiring at least 6 h per day of invasive mechanical ventilation for more than 21 consecutive days—is a major challenge in critical care, associated with prolonged weaning, high ventilator-associated complication rates, and substantial morbidity and mortality. A key driver of poor outcomes is ventilator-induced diaphragmatic dysfunction (VIDD), characterized by rapid diaphragmatic atrophy and functional decline. External diaphragm pacing (EDP), a non-invasive phrenic nerve stimulation technique, may enhance diaphragmatic contractility, while high-flow oxygen via tracheostomy (HFT) can optimize oxygenation, reduce respiratory workload, and improve comfort during weaning. However, no randomized controlled trial (RCT) has evaluated the combined effect of EDP and HFT on weaning outcomes in patients requiring PMV. Methods This is a single-center, randomized, controlled, open-label, trial conducted in the intensive care unit (ICU) of a rehabilitation hospital in Ningbo, China. We will enroll 60 adult tracheostomized patients with PMV and randomize them 1:1 to an experimental group (EDP + HFT) or a control group (standard care alone). The primary endpoint is time (days) from randomization to successful 24-h separation from invasive mechanical ventilation by day 28, without reconnection to the ventilator within the subsequent 48 h. Randomization will use a computer-generated permuted block design, with allocation concealed in sequentially numbered, opaque, sealed envelopes. Treating clinicians and patients will not be blinded, but diaphragm ultrasound assessors and statisticians will remain blinded to group allocation. Recruitment is planned from 1 November 2025 to 30 April 2026. Discussion This RCT will evaluate the efficacy and safety of combining non-invasive EDP with HFT to assist weaning in tracheostomized patients requiring PMV. If EDP + HFT is associated with reduced time to ventilator liberation and improved diaphragm function, it could serve as an accessible strategy to mitigate VIDD and improve weaning outcomes. Trial registration Chinese Clinical Trial Registry (ChiCTR): ChiCTR2500098295 (registered on 5 March 2025). Administrative information Note: The numbers in curly brackets refer to SPIRIT checklist item numbers. The order is modified to optimize flow (see SPIRIT 2013 statement).