Understanding the Purpose of Thickeners
Thickeners are powders or gels added to liquids and pureed foods to make them denser and easier to swallow for individuals with dysphagia. Dysphagia can be caused by various medical conditions, including stroke, Parkinson's disease, dementia, and head or neck cancers. For these patients, drinking thin liquids like water can increase the risk of aspiration, where fluid enters the lungs and can lead to serious respiratory infections like pneumonia. Thickening fluids slows down the liquid's flow, providing more time for the person to coordinate their swallowing safely. However, this critical intervention is not without its complications, and healthcare providers must carefully weigh the benefits against the potential risks.
Significant Side Effects of Thickened Liquids
Dehydration and Reduced Fluid Intake
One of the most frequently reported side effects of drinking thickeners is a reduced total fluid intake, which can lead to dehydration. This can be due to poor palatability, as many patients dislike the altered taste and texture. Thickened liquids may not effectively quench thirst, and their viscosity can lead to feeling full more quickly, reducing the volume consumed. Inconsistent access in some care settings can also contribute.
Gastrointestinal Issues
Thickening agents can contribute to various gastrointestinal problems. Reduced fluid intake is a primary cause of constipation. Gum-based thickeners, which are not fully digested in the upper GI tract, can lead to gas and bloating. A serious concern for infants is necrotizing enterocolitis (NEC), which has been linked to certain thickeners like those containing xanthan gum, making them unsuitable for infants under 12 months.
Impact on Medication Bioavailability
Thickened liquids can interfere with how the body absorbs medications. The increased viscosity can delay the dissolution of solid pills, potentially reducing their effectiveness. Consulting with a pharmacist is crucial to ensure proper medication administration when using thickened fluids.
Decreased Quality of Life
Thickened fluids can negatively impact a patient's quality of life. The altered taste and texture can make drinking unpleasant, potentially leading to non-compliance and increased aspiration risk. The social stigma associated with modified liquids can also be isolating. Research suggests some patients would consider a shorter life expectancy to avoid a diet of only thickened fluids.
Potential for Increased Aspiration Risk
While thickeners aim to reduce aspiration, they don't always eliminate it. Extremely thick liquids can leave residue in the throat that may be aspirated later. Some studies also suggest a potential link between thicker fluids and an increased likelihood of silent aspiration, where fluid enters the lungs without a cough response.
Comparison of Thickener Types
Commercial thickeners are generally either starch-based or gum-based, with differing properties and potential side effects.
| Feature | Starch-Based Thickeners | Gum-Based Thickeners | Potentials Issues |
|---|---|---|---|
| Composition | Modified cornstarch | Xanthan gum or other hydrocolloids | Gum-based linked to NEC in infants. |
| Stability | Unstable; continues to thicken over time and with refrigeration. | More stable; maintains consistent thickness over time if properly mixed. | Inconsistent thickness may lead to incorrect consistency and increased risk. |
| Taste/Texture | May impart a grainy texture and starchy flavor. | Can have a smoother texture but may alter flavor and mouthfeel. | Unpleasant palatability can lead to decreased intake and dehydration. |
| Saliva Interaction | Amylase in saliva can break down the starch, causing the liquid to thin out over time. | Generally more stable against saliva breakdown, maintaining consistency. | Starch-thickened liquids may become unsafe to swallow if left out. |
| Cost | Generally less expensive. | Generally more expensive. | Higher cost can be a barrier to consistent use. |
| GI Impact | Primarily associated with constipation due to lower fluid intake. | May cause gas and bloating as fiber is broken down in the intestines. | GI discomfort can further discourage intake. |
Best Practices for Managing Side Effects
To manage side effects, a formal swallow assessment by a speech-language pathologist and regular review of the consistency level are crucial. Monitoring hydration and nutrition, potentially with a dietitian's help, is essential if intake is low. Improving palatability by offering varied beverages or different thickener types can help. Proper and consistent preparation of thickeners is important. Consulting a pharmacist about potential medication interactions is necessary. Openly discussing the risks and benefits with the patient and family is vital for patient-centered care.
Conclusion
Liquid thickeners are a key tool for managing dysphagia but come with potential side effects like dehydration, constipation, reduced medication effectiveness, and lower quality of life. Mitigation strategies include monitoring fluid intake, addressing palatability, consulting pharmacists, and conducting regular swallowing assessments. Balancing safety with hydration, nutrition, and well-being through informed, patient-centered care is paramount.
