Condition category
Not Applicable
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
A nasogastric tube (NGT) is a tube used for giving medication and nutrition that is passed into the stomach via the nose. At least 1 million nasogastric tubes (NGT) are used in the UK each year, often for supplementary feeding in patients unable to swallow. These are tubes that are placed from the nose to the stomach to allow liquid feed to be passed directly into the stomach. It is important that these tubes are correctly placed before use as misplacement can lead to serious complications and even death. Current best practice uses pH testing (measuring acidity or alkalinity) to gastric (stomach) aspirates (matter that has been drawn from the body by suction) to ensure correct positioning in the stomach. This has limitations as it is not always possible to collect 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 means of determining nasogastric tube position on its own. The aim of this study is to find out whether a combined test for pH and gastric lipase is as accurate as the current best practice technique of a standard pH test.

Who can participate?
Adult patients who need NCT placement as part of their care.

What does the study involve?
As part of the normal clinical management, the NG tube is checked before being used for treatment. The current method of confirmation for correct NG tube placement is by aspirating (sucking out) gastric content from the tube and checking the pH level using pH strips. This is a painless process that is done routinely by the nurses. The same aspirate will be used to impregnate the novel lipase/pH test strip. The second phase of the clinical trial involves endotracheal (ET) tube testing. Patients who have ET tube as part of their routine clinical management will be invited to the trial. Lung fluid is aspirated from the ET tube and tested on the new lipase/pH test strip. This process is to ensure that the novel lipase/pH strip is able to determine incorrect lung placement of NG tubes.

What are the possible benefits and risks of participating?
Participating in the clinical trial is voluntary and patients do not receive payment of any kind. There are no direct benefits for patients participating the study. The procedures involved are part of routine management and does not affect their care and treatment. However, through their participation, they will be helping in the development of a new generation of pH strips that are safer and easier-to-use. This new strips has the potential to improve patient care. There are no notable risks to the patients having surgery.

Where is the study run from?
St. Mary's Hospital and seven other NHS hospitals in England (UK)

When is the study starting and how long is it expected to run for?
May 2015 to May 2018

Who is funding the study?
Innovate UK (UK)

Who is the main contact?
Ms Frances Domingo

Trial website

Contact information



Primary contact

Ms Frances Domingo


Contact details

10th Floor QEQM Building
St. Mary's Hospital
South Wharf Road
W2 1NY
United Kingdom
+44 (0)20 3312 6532

Additional identifiers

EudraCT number number

Protocol/serial number

IRAS 192968

Study information

Scientific title

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


Study hypothesis

The novel lipase/pH test is better than the standard pH strips used to confirm locations of blindly inserted nasogastric feeding tubes.

Ethics approval

London - Chelsea Research Ethics Committee, 30/09/2016, ref: 16/LO/0998

Study design

Observational cross-sectional multi-centre diagnostic accuracy study

Primary study design


Secondary study design

Cross sectional study

Trial setting


Trial type


Patient information sheet

See additional files


Patients with nasogastric tube in place for purpose of feeding and/or medication


The study will be undertaken in two phases:

Phase 1 - Diagnostic accuracy study
The gold standard (reference test) will be chest x-ray if undertaken or if not required the initiation of nasogastric feeding will determine correct placement. Patients who have nasogastric tube inserted for supplementary feeding or medications will be recruited to the study. They will have aspirates taken after initial insertion or before each use of the nasogastric tube for confirmation of correct placement, which is part of the routine management. The gastric aspirate that has been acquired by the ward staff for their routine testing will be utilised by being passed to a member of the research team to be used in the study. Therefore, the results of the study will not influence patient care. The results for both the enzymatic test and pH test will be compared to the reference test and recorded.

Phase 2 - A study to ensure that the test is able to determine incorrect lung placement of nasogastric tubes.
Patients undergoing routine general anaesthesia will be invited to participate. These patients have endotracheal tubes placed as part of their routine management. Techniques including capnography will be used to confirm that these tubes are correctly placed in the lung. These will be aspirated and used with the novel enzymatic test to ensure a negative result in the case of lung intubation.

Intervention type



Drug names

Primary outcome measure

Sensitivity of the index test and the reference tests (standard pH test) under cut-off 5.5 with tube sites confirmed by either patient follow up or chest x-rays when applicable.

Secondary outcome measures

1. Percentage unable to aspirate is measured by the number of patients for whom no aspirate is obtained out of the total number of patients for whom the attempts have been made before either successful aspiration or before chest x-rays has to be requested
2. Number of chest radiographs requested is recorded exactly as described, when aspirates and re-attempts both fail

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patients who require the insertion of nasogastric tubes for supplementary enteral feeding as part of their clinical management
2. Aged 18 years and over

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Under the age of 18 years
2. Unable to sign consent
3. Not providing consent
4. Prisoners
5. Patients sectioned under the Mental Health Act

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

St. Mary's Hospital
Imperial College Healthcare NHS Trust Praed Street
W2 1NY
United Kingdom

Trial participating centre

Hereford County Hosiptal
Wye Valley NHS Trust Union Walk
United Kingdom

Trial participating centre

Maidstone Hospital
Maidstone and Tunbridge Wells NHS Trust Hermitage Lane
ME16 9QQ
United Kingdom

Trial participating centre

Medway Maritime Hospital
Medway NHS Foundation Trust Windmill Road
United Kingdom

Trial participating centre

North Devon District Hospital
North Devon Healthcare NHS Trust Chichester House
EX31 4JB
United Kingdom

Trial participating centre

Royal Bournemouth Hospital
The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust Castle Lane East
United Kingdom

Trial participating centre

Royal Preston Hospital
Lancashire Teaching Hospitals Sharoe Green Lane North Fulwood
United Kingdom

Trial participating centre

Torbay Hospital
Torbay and South Devon NHS Foundation Trust Lawes Bridge
United Kingdom

Sponsor information


Imperial College London

Sponsor details

Joint Research Compliance Office
Charing Cross Hospital
W6 8RF
United Kingdom
+44 (0)20 7594 9459

Sponsor type




Funder type


Funder name

Innovate UK

Alternative name(s)

Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government


United Kingdom

Results and Publications

Publication and dissemination plan

Planned publication of the clinical study and the economic analysis that will be carried out based on the trial data and the human factors work package.

IPD Sharing statement:
The datasets generated during and/or analysed during the current study are/will be available upon request from Frances Domingo (

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

2017 results in:

Publication citations

Additional files

Editorial Notes

06/11/2017: Publication reference added.