Traditional NEX method versus modified length measurement for nasogastric tube placement in adults: a systematic review and meta-analysis

Abstract Objectives To systematically evaluate and compare the effectiveness and safety of modified length measurement methods versus the traditional NEX (nose–earlobe–xiphoid) method for nasogastric tube placement in adults. Methods PubMed, Embase, Web of Science, Cochrane Library, CINAHL, and Chinese electronic databases were searched for controlled studies comparing the two methods. A random-effects model was used to pool effect sizes. The primary outcome was the rate of appropriate tube position confirmed by imaging, and the secondary outcome was the incidence of tube-related adverse events. Results Four studies comprising 667 enrolled adult participants were included, of whom 635 were included in the reported analyses. Two parallel-group randomized controlled trials provided independent binary data suitable for quantitative synthesis of study-defined appropriate tube positioning. Modified measurement methods showed a directionally higher appropriate-placement rate than the traditional NEX method, but the pooled estimate was highly imprecise and not statistically significant (OR = 3.49, 95% CI 0.59–20.74; I 2 = 79.8%). In two studies reporting adverse events, the modified methods were associated with a reduced incidence of complications (OR = 0.10, 95% CI 0.05~0.21, I 2 = 0.0%). Only two randomized comparisons contributed to the primary quantitative synthesis, conventional leave-one-out sensitivity analysis was not considered informative. The consistency of findings was, therefore, assessed through design-based considerations and qualitative evaluation of excluded non-poolable studies. Conclusions Current evidence suggests that modified length measurement methods may improve the accuracy of nasogastric tube positioning and lower complication risks in adults. However, due to the limited number of included studies and underlying methodological heterogeneity, these findings should be interpreted cautiously; large-scale, multicenter, high-quality randomized controlled trials are warranted for definitive confirmation.