What exactly is a pressure ulcer? It is mechanical stress—pressure, shear or friction—that causes ischemic necrosis of at-risk soft tissue. Pressure ulcers were once thought to happen only to those spending most of their time in bed. Today, we know this is not the case.
Pressure ulcers can develop when a patient stays in any one position for a period of time and the blood flow to the area slows down or stops. It is these circumstances that result in injury to the soft tissue at risk and ultimately lead to the development of a pressure ulcer. When developing, a pressure ulcer starts on the inside and works its way out to the surface. It may take three to seven days for it to appear, but a pressure ulcer can form in as little as minutes depending upon the physiologic status of the patient.
To better understand the relationship between soft-tissue injury and support surfaces, we must realize support surfaces deliver a gradient pressure and/or shear mechanical stresses, which can lead to distortion of the soft tissue. The degree of the mechanical stress injury depends on both the media and container design of the support surface. Distortion causes endothelial and tissue-cell damage, which causes ischemia and possible infarction of the soft tissue at risk. The scientific disciplines of chemistry, physics and mechanics can help clinicians understand the mechanical stresses delivered by support surfaces to the patient at risk for pressure ulcer development.
With that said, all support surfaces used for pressure ulcer prevention and treatment, whether on the bed, seat or patients' lower extremities, should:
- Redistribute weight equally in a three-dimensional manner
- Minimize pressure, shear and friction injury
- Offer moisture and temperature control to control microenvironment
- Be easy to clean and minimize bioaerosol contamination
- Aid in patient transferring and mobilization
- Be compatible with multiple surfaces
- Fulfill regulatory requirements
- Flame retardant
- FDA Regulations
- Be cost effective
In addition, long-term caregivers' clinical protocols for pressure ulcers should address:
- Mobilization and ambulation
- Nutrition and hydration
- Moisture and incontibnence
- General medical co-morbidities and medications
- Existing pressure ulcers including deep-tissue injury
- Previous pressure ulcers (closed stage III, IV, unstageable and deep-tissue injury)
Caregivers with at-risk patients who spend time on a bed, cart or table should:
- Change patients' positioning every two hours meeting the medical needs of the patient
- Keep ankles and knees from touching each other using a pillow or air cushion
- Use a heel cushion to protect the ankle/heel/foot complex
- Place patients on an a static-air mattress overlay that addresses moisture, microclimate control, turning and transferring
Finally, caregivers with at-risk patients who spend time in a chair should:
- Assist patients in changing positioning every hour
- Require patients to shift weight every 15 minutes if possible
- Utilize a static-air surface
James G. Spahn, M.D., FACS, is the founder of Indianapolis-based EHOB, Inc., manufacturer of the WAFFLE® Brand Products for the prevention and treatment of pressure ulcers.