Objectives: This systematic review and meta-analysis aimed to evaluate the efficacy and safety of phrenic nerve stimulation (PNS) in mechanically ventilated adult patients. Methods: PubMed, Web of Science, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) up to 21 February 2026, without language restrictions. Two reviewers independently screened studies, extracted data, and evaluated the risk of bias using the Cochrane RoB 2 tool. The certainty of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were pooled using fixed-effects or random-effects models according to heterogeneity. Results: Five RCTs involving 431 patients were included. PNS was associated with a higher weaning success rate (OR = 2.96, 95% CI: 1.04 to 8.40, p = 0.04), a shorter duration of mechanical ventilation (MD = −2.63, 95% CI: −3.90 to −1.35, p < 0.001), higher maximal inspiratory pressure (MD = 2.95, 95% CI: 1.10 to 4.79, p = 0.002), and higher diaphragm thickening fraction (MD = 15.67, 95% CI: 4.84 to 26.50, p = 0.005). No statistically significant differences were observed in ICU length of stay, rapid shallow breathing index, or tracheostomy rate. Noninvasive stimulation was generally tolerated in the included studies, whereas transvenous stimulation was associated with procedure-related serious adverse events. The certainty of evidence ranged from high to low across outcomes. Conclusions: PNS was associated with improved weaning outcomes and diaphragm function in mechanically ventilated patients. However, the evidence remains limited by the small number of RCTs, clinical heterogeneity, and uncertainty regarding long-term outcomes. Further large-scale, multicenter RCTs with standardized protocols are needed to assess the efficacy and safety of PNS.
Wang et al. (Sat,) studied this question.