By Rosalyn S. Jordan, BSN, RN, MSc, CWOCN, WCC, and Sandra Phipps, BSN, RN, MBA, WCC
Pressure-ulcer prevention and management guidelines recommend support-surface therapy to help prevent and treat pressure ulcers. Support surfaces include pads, mattresses, and cushions that redistribute pressure. Full cushions and cushion pads are considered therapeutic support surfaces if used to redistribute a patient’s pressure in a chair or wheelchair.
The National Pressure Ulcer Advisory Panel (NPUAP) defines support surfaces as “specialized devices for pressure redistribution designed for the management of tissue loads, microclimate, and/or other therapeutic functions.” These surfaces address the mechanical forces associated with skin and tissue injury, such as pressure, shear, friction, and excess moisture and heat. (See Clearing up the confusion.)
A support surface may be integrated into the bed frame, supplied as a separate full mattress-replacement system, or (in the case of pads or mats) placed atop the mattress of a patient who has or is at risk for pressure ulcers. This article differentiates reactive and nonreactive support surfaces and explains how to choose appropriate support surfaces based on your patient’s needs. (See Clinician education on support surfaces.)
Tissue load and pressure redistribution
Tissue load refers to the pressure of the body surface and underlying tissue that come in contact with the support surface. It encompasses not just the patient’s weight but also body composition.
Immersion and envelopment properties
Immersion and envelopment properties of a support surface are crucial. Immersion refers to depth of penetration into the support surface by the load (patient’s body). Envelopment is the ability of the support surface to conform around the body. As the body’s contact area with the support material increases, pressure decreases.
Clinicians must ensure the support surface meets the patient’s specific needs. If the patient has some mobility, support-surface immersion and envelopment shouldn’t impede independent mobility.
Reactive vs active support surface
A support surface is categorized as reactive or nonreactive based on how it interacts with the skin and tissue.
Reactive support surface
A reactive support surface changes its load-redistribution properties only in response to an applied load (such as the patient’s body). The load sinks into the support surface and is enveloped by it. A reactive support surface accommodates the load by conforming to the body. It may be powered or nonpowered.
Active support surface
An active support surface is a powered surface capable of changing its load-
distribution properties with or without an applied load. Areas or specific cells within the support surface change constantly with inflation or deflation of specific air bladders, based on preset cycles. Changes in pressure within individual cells over a preset interval alter pressure on the skin and tissue periodically.
Addressing the skin’s microclimate
The microclimate is the skin’s heat and humidity (temperature and moisture level). Moist skin can result from sensible water loss (as with urinary incontinence) or insensible water loss (perspiration). Moist skin is a risk factor for pressure-ulcer development. Research shows that as the skin warms, moisture increases, weakening the skin. Other influences added to fragile skin, such as the mechanical forces of shear and friction, further increase pressure-ulcer risk.
Low-air-loss support surfaces help correct the skin’s microclimate. They maintain the skin’s heat and relative humidity by providing a flow of air that cools the skin and wicks away moisture. Managing the pressure along with the skin’s microclimate is important in preventing and healing pressure ulcers.
Shear is the force per unit area exerted parallel to the plane of interest. Shear forces cause tissue distortion and impede blood flow to the tissues, decreasing blood flow and tissue oxygenation. Forces that alter the skin’s blood flow and tissue perfusion are major risk factors for pressure ulcers.
Always consider shear forces when choosing a support surface for a patient. Shear causes a strain on tissues, leading to deformation where blood vessels are located. Most support surfaces have a cover that interfaces with the skin and reduces shear force. Usually, this material promotes sliding or gliding of the body or holds the patient in place to reduce shear.
Friction is resistance to motion in a parallel direction relative to the common boundary of two surfaces. Sliding one surface across another surface promotes friction. Friction usually occurs in conjunction with shear forces. The sliding motion may increase skin temperature. If moisture and heat have already weakened the patient’s skin, friction may contribute to superficial pressure ulcers. The cover of the support surface may help protect against the effects of friction, as can a turning sheet, turning device, and powered mechanical lifting and movement equipment.
When caring for a patient who has pressure ulcers or is at risk for developing them, consider the following NPUAP guidelines on selecting support-surface therapy:
- Choose a support-surface therapy that corresponds correctly to the patient’s condition.
- While the patient is receiving support-surface therapy, be sure to turn and reposition him or her based on individual needs.
- If pressure ulcers don’t heal, reevaluate the situation as needed and change or replace the support-surface therapy as required.
Call for clinical outcome data
NPUAP encourages clinicians and researchers to provide clinical outcome
data on the specific design, therapies, features, and benefits of specific support surfaces. Collection and publication of such data, in conjunction with clinician
education on support surfaces, could advance the clinical effectiveness of
Australian Wound Management Association. Pan Pacific Clinical Practice Guideline for the Prevention and Management of Pressure Injury. Cambridge Media Osborne Park, WA; 2012. www.awma.com.au/publications/2012_AWMA_Pan_Pacific_Guidelines.pdf. Accessed April 9, 2014.
Moore O, Jordan R. A survey of the knowledge of health care providers regarding therapeutic support surfaces. Poster presented at: Wild on Wounds conference; 2013. 9-2013; Las Vegas, Nevada.
National Pressure Ulcer Advisory Panel. Support surface standards initiative. www.npuap.org/resources/educational-and-clinical-resources/support-surface-standards-initiative-s3i/. Accessed April 9, 2014.
National Pressure Ulcer Advisory Panel. Terms and definitions related to support surfaces. www.npuap.org/wp-content/uploads/2012/03/NPUAP_S3I_TD.pdf. Accessed April 9, 2014.
National Pressure Ulcer Advisory Panel; European Pressure Ulcer Advisory Panel. Prevention and Treatment of Pressure Ulcers: Clinical Practice Guidelines. Washington, DC: National Pressure Ulcer Advisory Panel; 2009.
Reger SL, Ranganathan VK, McNulty AK. Use of a powered coverlet for moisture removal, skin temperature reduction, odor, and bacterial control. J Wound Ostomy Continence Nurs. 2014;41(1):35-9.
Sibbald RG, Goodman L, Woo KY, et al. Special considerations in wound bed preparation 2011: an update. Adv Skin Wound Care. 2011;24(9):415-36.
The authors work at RecoverCare, LLC, in Louisville, Kentucky. Rosalyn S. Jordan is the senior director of post-acute clinical programs and services. Sandra Phipps is the director of clinical services.
DISCLAIMER: All clinical recommendations are intended to assist with determining the appropriate wound therapy for the patient. Responsibility for final decisions and actions related to care of specific patients shall remain the obligation of the institution, its staff, and the patients’ attending physicians. Nothing in this information shall be deemed to constitute the providing of medical care or the diagnosis of any medical condition. Individuals should contact their healthcare providers for medical-related information.