Risk factors for diaphragmatic dysfunction in mechanically ventilated patients: a systematic review and meta-analysis.

OBJECTIVE: To systematically identify and evaluate the risk factors for diaphragmatic dysfunction (DD) in mechanically ventilated patients. METHODS: A comprehensive search of PubMed, Embase, Web of Science, CNKI, Wanfang, VIP, and CBM was conducted from database inception through July 2025. Case-control, cohort, and cross-sectional studies reporting risk factors for DD in mechanically ventilated patients were eligible. Two reviewers independently screened records, extracted data, and assessed risk of bias. Meta-analyses were performed using Review Manager 5.4. RESULTS: Eleven studies comprising 5,272 mechanically ventilated patients were included (7 cohort, 1 case-control, 3 cross-sectional). Meta-analysed risk factors: infection/sepsis (OR = 2.65, 95% CI: 1.32-5.34, p = 0.006), higher APACHE II score (OR = 1.19, 95% CI: 1.09-1.30, p < 0.0001), older age (OR = 1.02, 95% CI: 1.00-1.04, p = 0.02), and higher BMI (OR = 1.03, 95% CI: 1.01-1.06, p = 0.02) were each independently associated with increased DD risk. Meta-analysed protective factors: higher serum albumin (OR = 0.88, 95% CI: 0.79-0.98, p = 0.018) and greater grip strength (OR = 0.70, 95% CI: 0.62-0.78, p < 0.0001) were protective. Narrative-only findings: MV-related exposures could not be pooled owing to incompatible operationalisations across five studies; surgery-related factors (CABG, valve replacement, CPB duration) yielded inconclusive results due to extreme inter-study heterogeneity (I 2 = 88-95%). CONCLUSION: Sepsis/infection, disease severity, advanced age, and elevated BMI are independent risk factors for DD in mechanically ventilated patients, whereas adequate nutritional status and preserved muscle strength are protective. Early identification of high-risk patients, nutritional optimisation, and infection control may reduce DD incidence. SYSTEMATIC REVIEW REGISTRATION: The publicly accessible registration URL is: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261302793, this systematic review was registered with PROSPERO under the unique identifier CRD420261302793.