Sun28November0628PM 35

A 55-year-old male is admitted to the intensive care unit with respiratory failure. He is intubated, sedated, and ventilated. A nasogastric tube is inserted to facilitate early enteral feeding.

Which one of the following is the most important first line investigation that will help support the correct positioning of the tube in the stomach?

(Please select 1 option)

Use a magnet tracking device

pH testing of gastric aspirate using non-quantitative litmus paper

Inject air into the nasogastric tube with a syringe and auscultate the epigastric area for bubbling sounds

Chest x ray

pH testing of gastric aspirate using indicator paper Correct

Explanation

The misplacement of a nasogastric tube (NG) in the lungs and proceeding to 'enteral feeding' is a potential cause of death. The National Patient Safety Agency (NPSA) and Medical Protection Society (MPS) have highlighted the potential for catastrophe and suggested methods of preventing such 'never-events'. Between 2005 and March 2011 the NPSA were notified of 21 deaths and 79 cases of harm secondary to a misplaced NG tubes.

The first line test to confirm correct placement is to test the gastric aspirate with pH indicator paper. If the pH is between 1 and 5.5 then this is confirmatory evidence of correct placement. If there is any doubt, then an appropriately interpreted chest x ray is a second line investigation.

There is no place for the use of non-quantitative litmus paper or the 'whoosh' and 'blow' tests, as these methods are notoriously unreliable.

New devices that track the passage of a magnetised tip of a nasogastric past the diaphragm are currently being assessed. Their role in confirming correct placement is not established yet.

Reference:

Medical Protection Society (MPS). Nasogastric tube errors.

National Patient Safety Agency (NPSA). Reducing the harm caused by misplaced nasogastric feeding tubes in adults, children and infants.

Answer Statistics

1

6%

2

13%

3

19%

4

64%

Times answered: 290