Accuracy of Bedside Methods for Preliminary Nasoenteric Tube Tip Localization in Intensive Care: A Prospective Diagnostic Study

BACKGROUND: Postpyloric nasoenteric feeding reduces feeding intolerance and is recommended for critically ill patients. However, reliable confirmation of tip location remains challenging. Although radiography is the pre-feeding gold standard, repeated use of radiography during insertion is impractical in resource-limited intensive care units (ICUs). AIM: The aim of this study was to evaluate the accuracy of five bedside methods for preliminary nasoenteric tube tip localization against radiography. Secondary objectives included safety assessment and determining the optimal cut-off for pH difference in aspirate. STUDY DESIGN: This prospective, blinded diagnostic accuracy study was conducted in a tertiary ICU following the STARD 2015 guidelines, using a two-stage assessment procedure: initial gastric verification followed by postpyloric advancement. All participants underwent five index tests performed by a trained senior nurse: pH difference in aspirate (comparing gastric and post-advancement aspirate), pH testing of aspirate, auscultation of bubbling sounds, palpation for bubbling sounds and ultrasonographic gastric antrum assessment. Abdominal radiography served as the reference standard. The area under the curve (AUC) was calculated for each test with pairwise comparisons. Adverse events were monitored within 24 h. The optimal pH difference in aspirate cut-off was determined using Youden's index. RESULTS: Between October 2021 and January 2022, 60 patients were enrolled; postpyloric placement was confirmed in 47 (78.3%). Palpation for bubbling sounds (AUC 0.902), ultrasonographic gastric antrum assessment (AUC 0.863) and pH difference in aspirate (cut-off ≥ 1, AUC 0.808) demonstrated superior accuracy compared with auscultation (AUC 0.622) and pH testing of aspirate (AUC 0.586) (all p < 0.05). The optimal pH difference in aspirate cut-off was ≥ 1, yielding 100% sensitivity. No adverse events occurred. CONCLUSION: Palpation for bubbling sounds, ultrasonographic gastric antrum assessment and pH difference in aspirate are accurate bedside methods that can guide nurse-led nasoenteric tube placement, reduce interim radiographs and reserve mandatory confirmation for pre-feeding safety checks. RELEVANCE TO CLINICAL PRACTICE: This study validates three accurate bedside methods-pH difference in aspirate, palpation for bubbling sounds and ultrasonographic gastric antrum assessment-that can be integrated into nurse-led protocols to guide nasoenteric tube placement in resource-limited ICUs, reducing reliance on interim radiographs while maintaining patient safety.