Comparison of neck ultrasonography with a pH meter to confirm correct position of nasogastric tube.

PURPOSE The aim of this study was to compare pH meter and neck ultrasonograph for evaluation of nasogastric tube (NGT) position. METHODS A total of 35 adult patients who required NGT insertion were included. The NGT was inserted by an anesthetist after endotracheal intubation, and the transducer was placed transversely on the neck, just superior to the suprasternal notch. The passage of the NGT in the esophagus was evaluated by a sonographer, and the stomach was emptied by nasogastric suction. Secretion from inside the NGT was analyzed using a pH meter. The tip of the NGT was accepted as being in the stomach if the pH measured between 1 and 5. Neck ultrasonography was compared with the pH meter analysis for confirmation of NGT position. RESULTS Ultrasonography was highly sensitive (100% (95% CI 89.6-100%) and specific (97.2% (95% CI 85.4-99.5%) for evaluation of NGT position. The specificity for the pH meter was 100% (95% CI 16.6-100%), while the sensitivity was 76.5% (95% CI 58.8-89.2%). CONCLUSIONS This study showed that neck ultrasonography is more sensitive than the pH meter for confirmation of NGT position.