IDDSI Flow Test

In this short article we’ll briefly explain how to use the IDDSI flow test to evaluate the thickness of a drink in relation to the IDDSI Framework. We’ve included videos so you can see the IDDSI flow test in action.

IDDSI Flow Test

The flow test requires two 10 ml Luer tip hypodermic syringes like the ones in the illustration above. IDDSI originally understood these syringes to be internationally standardised to ISO 7886-1. However, it is only the nozzles that are standardised. The dimensions of the barrel can vary between manufacturers which will affect flow test results. To conform with the IDDSI flow test, the length from the 0 to the 10 ml mark on the syringe’s barrel must be 61.5 mm.

Flow Test Instructions

Here’s how to perform the IDDSI flow test:

1. Use a syringe to extract at least 10 ml of the drink to be tested.
2. Take a second syringe, which must have the dimensions as described above, remove the plunger and discard it.
3. Check the nozzle of the second syringe is clear and completely free of any plastic residue or manufacturing defects which might impede the flow and invalidate the result.
4. Hold the second syringe vertically in one hand with its nozzle pointing down and cover its nozzle with a finger of the hand you are holding it in.
5. With your other hand, use the first syringe to fill the second syringe with the drink to be tested up to its 10 ml level precisely.
6. Remove your finger from the nozzle of the second syringe for precisely 10 seconds then replace it. It is advisable to use a stop watch to time 10 seconds accurately.

Flow Test Results

The amount of drink that has flowed out of the syringe during 10 seconds determines the thickness level of the drink as follows:

• If less than 1 ml is left in the syringe, the drink is IDDSI Level 0 THIN
• If between 1 and 4 ml is left in the syringe, the drink is IDDSI Level 1 SLIGHTLY THICK
• If between 4 and 8 ml is left in the syringe, the drink is IDDSI Level 2 MILDLY THICK
• If between 8 and 10 ml is left in the syringe, the drink is IDDSI Level 3 MODERATELY THICK
• If 10 ml is left in the syringe, the drink is IDDSI Level 4 EXTREMELY THICK

Flow Test Videos

See the IDDSI flow test in action here:

IDDSI Flow Test Level 1

IDDSI Flow Test Level 2

IDDSI Flow Test Level 3

Although the flow test is useful, it does have some problems, issues and limitations which we’ll look at in our next article on the IDDSI Syringe Test (as it’s also known).

What are your thoughts on using the IDDSI flow test to check the thickness of dysphagia drinks? Please feel free to leave a response below.

References

© The International Dysphagia Diet Standardisation Initiative 2016 @http://iddsi.org/framework/