Diagnostic performance of muscular ultrasound in intensive care unit-acquired weakness: a systematic review and Meta-analysis

Abstract Background The performance of muscular ultrasound in diagnosing intensive care unit (ICU)-acquired weakness (ICUAW) is debated. We conducted this systematic review and meta-analysis to assess the diagnostic efficacy of muscular ultrasound in ICUAW. Methods Three researchers independently searched PubMed, Web of Science, Embase, Cochrane library, CNKI, VIP and Wanfang databases for articles published before May 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was employed to evaluate the methodological quality of the studies. A random-effects model was utilized to drive the summary estimates of sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence interval (CI), and summary receiver operating characteristic (SROC) curve was estimated. Additionally, a Fagan nomogram was constructed to calculate the post-test probabilities. Sources of heterogeneity were explored by subgroup analysis and meta-regression. Results This meta-analysis comprised nine prospective studies involving 485 participants, of whom 207 (42.68%) were diagnosed as ICUAW. Overall, the muscular ultrasound exhibited good performance for diagnosing ICUAW, with the area of SROC curve of 0.84 (95%CI 0.81–0.87), sensitivity of 0.76 (95%CI 0.70–0.82), specificity of 0.79 (95%CI 0.73–0.83), and DOR of 11.61 (95%CI 7.43–18.13). The included studies exhibited heterogeneity. Upon subgroup analysis, rectus femoris exhibited significantly superior discriminatory ability in identifying ICUAW when compared to the non-rectus femoris, with higher specificity (0.84 [95%CI 0.76–0.90] versus 0.71 [95%CI 0.64–0.77], p = 0.04) and SROC (0.89 [95%CI 0.86–0.91] versus 0.76 [95%CI 0.72–0.79], p < 0.01). Moreover, cross-sectional area was more effective than thickness, with higher specificity (0.84 [95%CI 0.77–0.89] versus 0.74 [95%CI 0.68–0.79], p = 0.02) and SROC (0.85 [95%CI 0.82–0.88] versus 0.76 [95%CI 0.72–0.80], p < 0.01). Furthermore, the integrated analysis of these two indicators revealed that the cross-sectional area of rectus femoris was statistically superior to the thickness of rectus femoris, with higher SROC (0.87 [95%CI 0.83–0.89] versus 0.80 [95%CI 0.76–0.83], p < 0.01). Conclusion Muscular ultrasound has potential to be a reliable tool for ICUAW diagnosis. Comparing to alternative indices, the cross-sectional area of the rectus femoris exhibits superior diagnostic efficacy and may be considered as a valuable parameter for clinical application.