Hold that x-ray: aspirate pH and auscultation prove enteral tube placement

We report here a prospective study evaluating an alternative to the roentgenographic confirmation of "fine-bore" nasoenteral feeding tubes. Of 78 nasoenteral intubations in 46 patients using a Dobbhoff (Biosearch Medical Products) weighted enteral feeding tube, gastric aspirates were evaluated in 28. Auscultation was performed in all 78. Data was collected at initial placement prior to x-ray confirmation. Observers used color-coded pH paper to analyze gastric aspirate (pH < or = 4) and/or auscultation of the epigastrium to determine feeding tube position prior to x-rays. Auscultation alone was ineffective as a confirmatory test with only 6.3% specificity (p = 0.31). Aspiration to ascertain tube position was very accurate when pH < or = 4.0 (p = 0.0005) and when it was performed. A pH value of > 4 was not very helpful in predicting malposition (37%) especially when pH altering medications were used. Aspiration of contents was successful in 85% of patients. We conclude that when the pH of the nasogastric tube aspirate is < 4.0, x-ray films are not needed to prove the accuracy of tube placement. In other situations, a film is indicated since auscultation is inaccurate.