- Six studies were retrieved that met inclusion and exclusion criteria
- Generally favourable results were seen for pH testing, aspiration, bilirubin and enzyme tests in prediction of correct nasogastric tube placement confirmed by radiography.
- Specific limitations of the studies:
- Some of the tests (bilirubin and enzyme) used are not currently available at the bedside - Some of the tests are only effective in determining placement under a narrow set of circumstances, e.g. pH assisted feeding tubes in children, pH of aspirate when it is <4.0, pH and enzymes in adults - Sensitivity and specificity of the tests were not determined for most of the papers.