(Micro)Climate Change
Pressure injuries (PIs) are a significant concern for individuals with disabilities, particularly for those who rely on wheelchairs for mobility or spend extended periods in bed. At their core, pressure injuries are wounds that develop when skin breaks down over bony areas of the body. Common locations include the heels, buttocks, and back—areas where our skeleton bears the most weight. If not addressed promptly, these injuries can take months or even years to heal and may require hospitalization for advanced medical and nursing care.
A pressure injury begins when pressure from bony areas impedes blood flow to the skin, restricting oxygen and nutrients while allowing cellular waste to accumulate. This problem is compounded by friction and shearing. Friction occurs when the skin rubs against surfaces like cushions, mattresses, or chairs, while shearing happens when bones move against surrounding tissues. Today’s focus is on another crucial factor: microclimate.
Humidity is making this delicate fern moist, just as it does to our skin.
The Impact of Microclimate on Pressure Injuries
Each part of our body has its own microclimate, defined by variations in airflow, humidity, temperature, and moisture. For example, the skin on your forehead differs significantly from the skin in your underarm. The underarm area, which is frequently exposed to sweat and has less ventilation, tends to be warmer and more humid compared to the forehead. These microclimate differences can affect skin health, making it either excessively dry and brittle or overly wet and fragile—both of which increase the risk of pressure injuries. Incontinence can also exacerbate these issues.
Recent Research on Microclimate and Pressure Injuries
A recent study by Liz Couzens and her team in Australia examined how microclimate impacts pressure injury development. The researchers reviewed evidence on how different cushion types affect temperature and humidity in the localized area. The findings suggest that higher temperatures and humidity levels lead to increased moisture and sweat, which can compromise skin integrity and elevate pressure injury risk. The study evaluated three types of cushions:
Air Cushions
Foam Cushions
Foam/Gel Cushions
The results showed:
Foam/Gel Cushions were the coolest option, with the researchers anticipating that gel helped to draw heat away from the body. Foam/gel cushions were found to be up to 2.3°C cooler than pure foam cushions.
Air and Foam Cushions had minimal differences in temperature.
In terms of humidity management, Foam Cushions were the best, with the research team attributing this to foam’s ability to absorb moisture more efficiently. Air and foam cushions showed minimal differences in this regard.
Interestingly, participants in the study did not report significant differences in temperature or humidity between the cushion types in a controlled environment. Real-life applications of these findings may vary and warrant further exploration.
Implications for Wheelchair Users
This research is particularly relevant given Mildura’s extreme summer heat, which can exacerbate sweating and temperature regulation issues for wheelchair users. Understanding how different cushions affect microclimate can help minimize the risk of pressure injuries. While these research outcomes provide valuable guidance, they are not definitive rules. An individualized, comprehensive assessment remains the best approach to achieving optimal outcomes.
At Weave, we are dedicated to ensuring that all wheelchair users experience the highest level of comfort, efficiency, safety, and support. If you have concerns or frustrations with your wheelchair, cushion, or any attachments, we would be pleased to assist you. Please reach out through our contact page for support.
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Thanks go to the research team for this valuable research - A reference to their work is below:
Couzens, L., Peterson, B., Innes, E., & Stevens, C. J. 2024. The effect of wheelchair cushion properties on the microclimate at the cushion-user interface: A systematic review and meta-analysis. Australian Occupational Therapy Journal, (Online ahead of print)