Why It’s SO Important To Test The Thickness Of A Drink

In this brief article, we answer the question: “Why test the thickness of a drink that has thickener added for someone with dysphagia?”

Why it’s important that drinks are the correct thickness

As explained in our article on dysphagia treatment and management a person with dysphagia (swallowing difficulty) may aspirate if they drink “thin” liquid. Aspirate means the drink goes “the wrong way” down the trachea into the lungs rather than down the oesophagus into the stomach.

Aspiration is unpleasant and can cause discomfort, pain, coughing and choking, If persistent, it can lead to dehydration and pneumonia which can be fatal.

Adding thickener to drinks makes them more cohesive or “sticky”. This may make it easier for someone who has dysphagia to swallow their drink safely without some of it being aspirated.

However, drinks that are too thick can increase the risk of some being left in the throat after the swallow which may be aspirated or cause choking.

Some people find thickened drinks unpleasant. The thicker the drink, the more unpalatable it may be. So if drinks are thicker than they need be, they may be left undrunk. Thicker drinks may also make someone feel full before they really are. This can lead to dehydration.

The thickener can also slow down or decrease the body’s ability to absorb or digest certain medicines that are taken orally.

People with dysphagia have different swallowing abilities and therefore require drinks of different thickness. Because of this, it’s important to provide drinks of the correct consistency for each individual: not too thin and not too thick.

Why you can’t rely on the thickener manufacturer’s instructions

Thickener manufacturers state how much thickener should be added to a drink to achieve a particular level of thickness. But this is only a guide. As explained in problems with thickened drinks, the amount of thickener required to achieve a certain level of thickness varies due to type of drink, temperature and time.

Type of drink

Different drinks such as water, fruit juice, tea, milk require different amounts of thickener to reach the same level of thickness. It isn’t possible for the thickener manufacturer to provide instructions on exactly how much thickener to add to every type of drink to achieve a certain consistency.

Temperature

The consistency of a thickened drink may vary based on its temperature. Thickened drinks tend to be thicker when cool and thinner when hot. So a different amount of thickener needs to be added to the same drink served chilled, at room temperature or heated up.

This is explained in more detail here: www.iddsi.org/News/Special-Features/Why-Temperature-Is-So-Important

It isn’t possible for the thickener manufacturer to provide instructions on exactly how much thickener to add to drinks at different temperatures to achieve a certain consistency.

Time

It can take several minutes for the thickener to have full effect on a drink and reach the intended consistency. Milk takes even longer, 15-30 minutes! If drunk during this period, the drink will be thinner than intended.

Some thickeners continue to slowly thicken drinks over time. So a drink prepared to the correct consistency may become too thick if not drunk soon after the thickener was added.

A drink thickened with starch-based thickener, rather than gum-based thickener, can become thinner if drunk slowly over time. This is because there is an enzyme in saliva called amylase that breaks down starch.

Because the consistency of thickened drinks varies due to temperature as described above, a chilled drink will become thinner as it warms up and a hot drink will become thicker as it cools down.

Whilst thickener manufacturers can provide guidance on how much of their product to add to a drink to achieve a certain consistency, they can’t take into account how that consistency might change over time.

Mistakes

When thickening a drink, sometimes not all the thickener is mixed in to the drink with some forming in to lumps. The drink will then be too thin.

Research has shown that drinks are often thickened to a consistency other than that prescribed for the person with dysphagia.

Thickeners are often mixed incorrectly by carers and the required fluid viscosity may not be achieved.

Chadwick D, et al. Adherence to eating and drinking guidelines for adults with intellectual disabilities and dysphagia. Am J Ment Retard2003; 108 (3): 202–211

Such mistakes can be a serious problem …

Noncompliance with recommendations about dysphagia management is associated with adverse outcomes. There was a high mortality rate and aspiration pneumonia was a common cause of death

Low J, et al. The effect of compliance on clinical outcomes for patients with dysphagia on videoflouroscopy. Dysphagia2001; 16: 123-127

Confusion and miscommunication regarding diet textures and drink consistencies has resulted in increased risk of illness and even death.

www.iddsi.org/framework/what-is-dysphagia

IDDSI flow test

You can use the IDDSI flow test to evaluate the thickness of a drink in relation to the IDDSI Framework. But it has some problems, issues and limitations that we list below. These are explained in more detail in our article on the IDDSI syringe test (as it is also known).

• You can’t just use any syringe. You need a syringe with the correct dimensions (or the IDDSI Funnel).
• The correct syringes aren’t always easy to get hold of.
• Few people will have access to the correct syringe or Funnel outside of the clinical setting.
• It requires a degree of dexterity that some people may lack.
• It requires a high degree of accuracy: slight errors in the quantity of drink used or in timing can lead to incorrect results.
• It’s quite “fiddly” and more suited to training than testing each and every drink.

The quick easy accurate drink thickness test

By contrast, the Viscgo drink thickness test sticks are simple, quick and practical to use. They can be used by most people to make sure that each and every drink that has been thickened with xanthan gum-based thickener is at the prescribed consistency.

And they can be used to quickly and easily re-test the drink to see if it’s level of thickness has altered over time, perhaps because of a change in temperature.

Further information

For more information on our range of drink thickness test products, click the links below:
Assessment Kit, Level 1 Test Kit, Level 2 Test Kit, Level 3 Test Kit, Viscgo Sticks.