Diagnostic accuracy of POC enzymatic test for NG tube placement.

  • Research type

    Research Study

  • Full title

    A diagnostic accuracy study to evaluate a point-of-care lipase/pH test strip to confirm correct nasogastric tube position.

  • IRAS ID

    192968

  • Contact name

    George Hanna

  • Contact email

    g.hanna@imperial.ac.uk

  • Sponsor organisation

    Imperial College London

  • Duration of Study in the UK

    1 years, 0 months, 1 days

  • Research summary

    At least 1 million nasogastric tubes are used in the UK each year, often for supplementary feeding in patients unable to swallow. They allow liquid feed to be passed directly into the stomach. It is important that these tubes are correctly placed in the stomach prior to use as if misplacement into the oesophagus or lung is unrecognised feeding can result in patient harm and even death. Current best practice uses pH testing of aspirates to ensure correct positioning in the stomach. This has limitations as it is not always possible to generate an aspirate and up to 42% of patients receive medications that reduce acid in the stomach. In these patients, feeding is often delayed as patients have to wait for a repeat aspiration or undergo a chest x-ray.

    The ideal solution would be a test that was accurate, safe and rapid even in the context of non-acidic gastric aspirates. Gastric lipase is an enzyme produced in the stomach and therefore if present in aspirates from nasogastric tube confirms correct placement. However, gastric lipase is inactivated by acidic stomach contents and therefore is unsuitable as a means of determining nasogastric tube position on its own. A combined test for pH and gastric lipase may be significantly more accurate than each in isolation.

    The objective of this study is to determine the accuracy of a novel nasogastric tube position test that is compatible with non-acidic gastric aspirates by using gastric lipase to lower the pH of gastric aspirates on pH test paper. This will be carried out by comparing the new test to the standard pH test that is currently used. In addition a workshop with healthcare workers who will be using the test in their practice will be undertaken to gain their feedback regarding the new test.

  • REC name

    London - Chelsea Research Ethics Committee

  • REC reference

    16/LO/0998

  • Date of REC Opinion

    30 Sep 2016

  • REC opinion

    Further Information Favourable Opinion