What Is the Evidence to Support Ongoing Nasogastric Tube Position Testing? A Prospective Observational Study of Adverse Events in Australia and the United Kingdom.

Background: Ongoing nasogastric tube (NGT) testing guidelines aim to prevent the use of a displaced NGT; however, guidelines vary, and the relative risks and benefits of different testing methods are unknown.

Objective: To observe methods used in two hospitals to confirm ongoing NGT position and any differences in outcomes.

Methods: Data were collected prospectively from the medical records of 256 patients with NGTs across a London National Health Service Trust and a Brisbane hospital. These hospitals use different methods of ongoing NGT position confirmation, predominantly pH tests and external tube length measurement (ETLM), respectively. Statistical models explored outcomes associated with test results, including confirmation of NGT position, number of X-rays, and delivery of enteral nutrition and medication.

Results: Most ongoing NGT position tests in London were pH (83.4%) and in Brisbane were ETLM (98.6%). Overall, eight NGTs were reported as displaced, of which six were identified by oral cavity inspection. One hundred and eighty-five (31.8%) ongoing pH tests failed to confirm that the NGT remained correctly positioned. Failed ongoing NGT position tests were associated with significantly more X-rays, which resulted in disruptions to enteral nutrition and medications in London (n = 64, 47.1%) compared to Brisbane (n = 9, 7.5%) (p < 0.001).

Conclusions: Overall, NGT displacement occurred rarely. Compared to ETLM, pH tests frequently failed to confirm that the tube remained correctly positioned, resulting in X-rays and disruptions to enteral nutrition and medications. Oral cavity inspection alongside ETLM could be a safe alternative method to pH testing but requires more research to examine generalizability.