A prospective observational study of pH testing to confirm ongoing nasogastric tube position.

Kate Glen, Christine Elizabeth Weekes, Merrilyn Banks, Mary Hannan-Jones, Ismail Arbi

Journal: Journal of clinical nursing 2024;33(9):3624-3633

PMID: 38764202

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Abstract

AIMS AND OBJECTIVES

To measure the reliability of pH testing to confirm ongoing nasogastric tube (NGT) position and to document associated complications.

BACKGROUND

Confirming NGT position is essential, as use of an incorrectly positioned tube can cause harm. Substantial evidence examines initial confirmation of NGT position, yet limited evidence exists considers NGT displacement which is identified via ongoing NGT position tests. In the NHS, pH testing is recommended to confirm ongoing NGT position; however, there may be an association with excess X-rays and missed enteral nutrition and/or medications.

DESIGN

Prospective observational study using STROBE checklist.

METHODS

Data collected from medical records of 136 patients with NGTs in a London NHS Trust included pH tests, test results and complications related to ongoing pH tests which failed to confirm the tube was positioned in the stomach, that is, X-rays, and disruptions to enteral nutrition and medication. Cohen's Kappa determined pH test reliability.

RESULTS

Of 1381 pH tests conducted to confirm NGT position, five (0.3%) correctly identified an NGT displacement, and one (0.07%) failed to identify displacement before use. The reliability of ongoing pH tests using Cohen's Kappa was minimal (0.29). Ongoing pH tests that failed to confirm a correctly positioned NGT led to 31 (22.8%) patients having X-rays, 24 (17.6%) missing >10% of prescribed enteral nutrition and 25 (18.4%) missing a critical medication.

CONCLUSION

Ongoing NGT position testing using pH tests did not prevent the use of a displaced tube, and more than one-fifth of patients required X-rays to confirm a correctly position NGT, contributing to missed medications and enteral nutrition.

RELEVANCE TO CLINICAL PRACTICE

Caution should be used when confirming ongoing NGT position with a pH test. Future guidelines should balance the risk of using a displaced tube with potential delays to nutrition and/or medication. More research is needed to explore alternative methods of ongoing NGT position testing.

Address: Nutrition and Dietetics, University College London Hospital, London, UK.; School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.; Dietetics and Food Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.; School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.; Diversion Medicine, University College London, London, UK.; School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.; Dietetics and Food Service, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.; Pharmacy Department, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.; School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.

DOI: 10.1111/jocn.17188

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MeSH Terms: Humans, Intubation, Gastrointestinal, Prospective Studies, Hydrogen-Ion Concentration, Male, Female, Middle Aged, Aged, London, Enteral Nutrition, Reproducibility of Results, Adult