Understanding the 'Slightly Thick' Consistency
Level 1 thickener is used to prepare fluids with a 'Slightly Thick' consistency, which is a key part of the International Dysphagia Diet Standardisation Initiative (IDDSI) framework. This specific thickness is designed for individuals who have difficulty safely swallowing thin, watery liquids. By adding a thickening agent to beverages like water, juice, or tea, the liquid's flow rate is slowed, giving the person more time and control during the swallow to prevent liquid from entering the airway, a condition called aspiration.
Characteristics of Level 1 Thickened Liquids
- Flows more slowly: The primary characteristic is a slightly reduced flow rate compared to unthickened water. This subtle change is often enough to increase swallowing safety for those with mild dysphagia.
- Can be consumed with a straw: Unlike higher levels of thickeners, Level 1 fluids can typically be drunk through a standard drinking straw, requiring only a little more effort than a thin liquid.
- Leaves a light coating: The fluid may leave a slight coating on the inside of a glass after it is poured out, differentiating it visually from thin liquids.
- Neutral flavor: Modern thickeners, especially xanthan gum-based products, are generally neutral in flavor, helping to maintain the taste of the beverage.
Why and When is Level 1 Thickener Used?
The recommendation for Level 1 thickened liquids is made by a speech and language therapist after a thorough swallowing assessment. It is not a one-size-fits-all solution, but a precise, evidence-based intervention tailored to an individual's specific swallowing needs.
The need for thickened liquids often arises from conditions that weaken or affect the coordination of the swallowing muscles. This can include stroke, neurological disorders, or conditions related to aging. For some, the issue may be temporary, while for others, it is a long-term management strategy. The goal is to maximize swallowing safety while maintaining hydration and the enjoyment of drinking.
Benefits for Patients
- Improved Hydration: By making liquids safer to consume, patients are more likely to drink adequately, reducing the risk of dehydration.
- Reduced Risk of Aspiration: The slower flow rate helps prevent liquids from entering the lungs, which can lead to serious chest infections like aspiration pneumonia.
- Maintains Quality of Life: A less restrictive diet that includes a variety of beverages helps improve a patient's overall quality of life.
Types of Thickening Agents
Thickeners are typically available as a powder or gel that is mixed into a liquid. They are commonly categorized into two main types based on their base ingredients.
- Starch-based thickeners: These use modified corn or potato starches. A key consideration is that starch-based thickeners are susceptible to an enzyme in saliva called amylase, which can cause them to thin out in the mouth. This can be a concern for some patients. Starch thickeners are also known to leave a slightly grainy texture.
- Gum-based thickeners: Primarily made from xanthan gum, these thickeners are more common today due to their stability. They resist thinning when mixed with saliva, providing a more consistent thickness throughout the swallow. Xanthan gum also has a more neutral flavor profile and a smoother, less gritty texture.
Verifying the Consistency with the IDDSI Flow Test
To ensure the fluid is the correct thickness, the IDDSI provides a simple, reliable verification method using a 10 mL syringe. This test is critical because different brands and beverage types may require different amounts of thickener to reach the same level.
IDDSI Flow Test Procedure
- Fill a 10 mL slip-tip syringe with exactly 10 mL of the prepared thickened liquid.
- Cover the nozzle of the syringe with a finger to prevent spillage.
- Start a stopwatch and release your finger, allowing the liquid to flow out for exactly 10 seconds.
- After 10 seconds, cover the nozzle again and measure the amount of liquid remaining in the syringe.
For a Level 1 'Slightly Thick' liquid, there should be between 1 mL and 4 mL of liquid remaining in the syringe.
| Feature | Level 1 (Slightly Thick) | Level 2 (Mildly Thick) |
|---|---|---|
| Appearance | Thicker than water; leaves a slight coating on a glass. | Thicker than Level 1; pours more slowly than water, similar to a creamy soup. |
| Flow Rate | Reduced flow compared to water, but still flows easily. | Pours quickly off a spoon but slower than a thin liquid. |
| Straw Use | Can be drunk through a standard straw with minimal extra effort. | Requires some effort to be sucked through a standard straw. |
| IDDSI Flow Test | 1-4 mL remains in a 10 mL syringe after 10 seconds. | 4-8 mL remains in a 10 mL syringe after 10 seconds. |
| Examples | Some fruit nectars, naturally. | Some milkshakes, naturally. |
Conclusion
Level 1 thickener, a cornerstone of the IDDSI framework, provides a safe and effective way to manage mild dysphagia. By creating a 'slightly thick' liquid, it helps reduce the risk of aspiration while allowing patients to enjoy their beverages with greater ease and confidence. The availability of advanced gum-based thickeners has made this process more palatable and consistent, improving patient compliance and hydration. Always follow the guidance of a healthcare professional and use the IDDSI Flow Test to ensure the correct consistency is achieved for maximum safety. The continuous advancement of dysphagia care, including specialized thickeners and testing methods, helps improve the quality of life for those with swallowing difficulties.
