WP_PressureUlcersAnOverviewOfAPainfulProblem_20131011_VF.pdf

White PaperAUGUST 2013

Why do Pressure Ulcers Occur? Pathophysiology of Pressure Ulcers

BY: KINDAH JARADEH

White Paper OCTOBER 2013

Pressure Ulcers: An Overview of a Painful Problem

Education Evidence Evaluation

Bruin Biometrics, LLC (BBI) is pleased to provide this series of white papers to help lay readers understand commonly debated topics in pressure ulcer research and clinical practice. These papers are the distillation of a comprehensive literation search and review, rather than the result of primary research.

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Pressure Ulcers: An Overview of a Painful Problem

Introduction Pressure ulcers, commonly known as bedsores, are a problem experienced internationally. They affect patient quality of life and impose a heavy resource and financial burden on healthcare systems. A pressure ulcer is localized injury to the skin and/or underlying tissue usually over a bony prominence, such as a heel or an elbowi (see Illustration I). This injury is caused by the inability of the skin and the supporting tissues to redistribute external pressure, including mechanical loading, friction, and shear (parallel force).ii Most pressure ulcers occur over bony prominences where there is less tissue for compression and the pressure gradient within the vascular network is altered.iii,iv The most common anatomic location of all pressure ulcers is the sacrum (28.3%), followed by the heel (23.6%) and buttocks (17.2%) v (see Illustration I). Based on the 2008 and 2009 International Pressure Ulcer Prevalence Survey, the overall prevalence of pressure ulcers was 12.3% across all care settings.vi Long-term acute care settings that serve patients with complex medical problems who require extended hospital stays have the highest overall prevalence of any care setting at 29.3%, with rehabilitation next at a range of 16.3% to 19.4%, and acute care settings at approximately 11.9%.vi

Illustration I: Common sites of pressure ulceration in individuals at-risk of pressure

ulcers.vii Pressure ulcers present a significant health and economic concern. They account for 60,000 deaths, 2.3 million incremental hospital days and an estimated $9.1-$11.6 billion per year of care costs in the United States.viii,ix The cost of individual patient care ranges from $20,900 to $151,700 per pressure ulcer, which adds $43,180 to a hospital stay.ix

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Similarly, in the United Kingdom, pressure ulcer care costs the healthcare system 2.1 billion per year ($3.4 billion).x These costs are driven by nursing time to monitor, assess, and dress wounds, utilization of appropriate treatment therapies, as well as duration of hospital stay, based on the severity of the pressure ulcer. For example, the most severe pressure ulcers (Stage IV) require an average of 155 days recovery timex and $129,248 for treatment of the ulcer and related complications during a single hospital admission.xi The result is an average hospital length of stay (LOS) that is 4.5 times longer than patients without pressure ulcers.xii Pressure Ulcer Classification The current standard of detection for pressure ulcers relies mainly on visual inspection. Visual inspection is used to detect and classify pressure ulcers according to the ulcers depth, width, degree of tissue loss, and presence of granulated tissue. The National Pressure Ulcer Advisory Panel (NPUAP) in conjunction with the European Pressure Ulcer Advisory Panel (EPUAP) categorizes pressure ulcers into one of six stages; 4 depth stages (Stages I-IV) and 2 additional stages to indicate deep tissue injury or an ulcer that cannot be classified. The NPUAP/EPUAP developed this classification system to ensure consistent and accurate wound categorization as a means to achieving proper treatment, as well as to help with diagnosis coding for reimbursement (ICD-9 and ICD-10 codes). Details about each stage are included in Table 1.

Stage Description Example

Normal or Healthy Skin

Intact skin No visible bruising or skin discoloration Skin is pain-free, and temperature is consistent across surface

Stage I: Non-blanchable erythema

Intact skin with non-blanchable redness of a localized area, usually over a bony prominence

Darkly pigmented skin may not have visible blanching; its color may differ from the surrounding area

The area may be painful, firm, soft, warmer or cooler as compared to adjacent tissue

Stage II: Partial Thickness Skin Loss

Partial thickness loss of dermis presenting as a shallow open ulcer with a red pink wound bed, without slough

May also present as an intact or open/ruptured serum-filled or sero-sanginous filled blister

Presents as a shiny or dry, shallow ulcer without slough or bruising

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Stage Description Example

Stage III: Full Thickness Skin Loss

Full thickness tissue loss Subcutaneous fat may be visible but bone, tendon, or muscle

is not exposed or directly palpable Slough may be present but does not obscure the depth of

tissue loss May include undermining and tunneling

Stage IV: Full Thickness Tissue Loss

Full thickness tissue loss with exposed bone, tendon or muscle Slough or eschar* may be present. Often includes undermining and tunneling Category/Stage IV ulcers can extend into muscle and/or

supporting structures such as fascia, tendon or joint capsule Exposed bone/muscle is visible or directly palpable

Unstageable: Full Thickness Tissue loss with Unknown Depth

Full thickness tissue loss Actual depth of the ulcer is completely obscured by slough

(yellow, tan, gray, green or brown) and/or eschar (tan, brown or black) in the wound bed

Deep Tissue Injury (DTI) with Unknown Depth

Purple or maroon localized area of discolored intact skin or blood-filled blister due to damage of underlying soft tissue from pressure and/or shear

The area may be preceded by tissue that is painful, firm, mushy, boggy, warmer or cooler as compared to adjacent tissue

Evolution may include a thin blister or eschar over a dark wound bed

Evolution may be rapid, exposing additional layers of tissue even with optimal treatment

Table 1: NPUAP/EPUAP Pressure Ulcer Classification Systemxiii

Progression and Reverse Staging Pressure ulcers do not always progress chronologically (through Stages I, II, III, etc.) in formation or healing.xiv For example, tissue damage does not always present as Stage I pressure ulcer, which then develops into higher stage ulcer. In some instances, the first sign of a pressure ulcer is a deep III or IV ulcer, because the subcutaneous tissue can become necrotic before the epidermis erodes. This finding suggests that a small surface ulcer may in fact represent extensive subcutaneous damage.xv Once a pressure ulcer develops, tissue damage is not easily reversed. Previously, it was generally accepted that a pressure ulcer would reverse stage throughout the healing process and be re-classified at a lower stage.

* Eschar: Dried, black, hard, necrotic tissue xxxii Tunneling: A tract heading away from the wound base in any direction xxxiii Slough: Soft, yellow, brown, or gray material and is characterized by its stringy, adherent quality xxxiii

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(Stage IV becomes Stage III, then Stage II, Stage I, until the skin is again healthy). However, experts now dismiss this practice because it is physiologically incorrect. While pressure ulcers do heal to a progressively shallower depth, a healing wound is not filled by normal tissue; lost muscle, subcutaneous fat, and dermis is not replaced. xvi Rather, the wound is replaced by scar tissue that is composed of endothelial cells, fibroblasts, collagen, and extracellular matrix.xvi Therefore, it is not appropriate to say that a Stage II pressure ulcer will heal to a Stage I assessment.xvii Instead, a pressure ulcer maintains its first classification stage, and the term healing is added as a prefix. For example, a Stage IV pressure ulcer that is improving is designated a healing Stage IV pressure ulcer; it is no longer reverse staged to Stage III or II. Most Pressure Ulcers Are Avoidable When a caregiver follows the guidelines for patient care that include repositioning bed-ridden patients approximately once every hour, the risk of developing a pressure ulcer dramatically decreases. In 2010, the National Pressure Ulcer Advisory Panel (NPUAP) hosted a multidisciplinary conference to establish consensus on whether or not pressure ulcers are avoidable. Eighty-two percent of the clinicians on the conference panel agreed that most pressure ulcers are avoidable. The instance when the development of a pressure ulcer was considered unavoidableby a unanimous vote of all 24 panelistswas hemodynamic instability (a state requiring pharmacologic or mechanical support to maintain a normal blood pressure or adequate cardiac output), which is worsened by physical movement.xviii The rationale for agreeing that pressure ulcers are largely preventable stems from the fact that when a care-giver follows well-established guidelines for patient care, which include but are not limited to mobilizing patients regularly, ensuring proper nutrition, effectively managing moisture at the skins surface, the likelihood that a patient will develop a pressure ulcer dramatically decreases. The Center for Medicare & Medicaid Services (CMS) also concluded that most pressure ulcers are avoidable. As of October 2013, CMS reimbursement for hospital-acquired Stage III and IV pressure ulcers will cease. Because pressure ulcers are reasonably preventable, CMS has deemed them never events, namely events that should never happen in a provider setting. Private insurers in the United States are also adopting these reimbursement restrictions.xix Similarly, the United Kingdom has adopted a zero tolerance approach toward pressure ulceration.xx

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Failure to Detect Pressure Ulcers Have Serious Consequences Forty-two percent of patients with a Stage I pressure ulcer progress to higher stages of ulceration. Treatment costs quadruple, from Stage I (1,214 or approximately $1,966) to Stage II (5,241 or approximately $8,485).x A 1998 study found that Stage I ulcers deteriorated to a higher stage in 23.3% of the patients undergoing surgery lasting more than 4 hours.xxi,xxii In acute care hospitals, more than 1-in-5 Stage I pressure ulcers deteriorated to higher stages in one week.xxii The failure to identify a Stage I pressure ulcer during a skin assessment leads to increased incidence of Stage II ulcers, particularly in patients with darker skin tones.v Acknowledged difficulties with commonly accepted practices of pressure ulcer detection help explain incidence rates.

1. Sensitivity & Specificity: Visual inspection, even when combined

with paper and pencil risk assessment tools (e.g., Braden Scale, Norton, Waterlow) lack sensitivity and specificity (see Table 2).xxiii Differentiating between epidermal irritation and sub-epidermal injury becomes more a matter of individual perception than science.

Tool Sensitivity Specificity Odds Ratio 95%

Confidence Interval

Braden Scale 57.1% 67.5% 4.08 2.56-6.48

Norton Scale 46.8% 61.8% 2.16 1.03-4.54

Waterlow Scale 82.4% 27.4% 2.05 1.11-3.76

Clinical Judgment 50.6% 60.1% 1.69 0.76-3.75

Table 2: Risk Assessment Tool Comparisonxxiv

2. Dark Skin Tones: Data show Stage I pressure ulcers are missed in patients with dark skin tones; instead, such patients develop four times as many Stage II pressure ulcers as compared to Stage I pressure ulcers.

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Figure 1: Prevalence of Pressure Ulcers by Skin Color.v

3. DTI and the Bottom-Up Formation model: Stage II and higher

pressure ulcers often occur suddenly without significant visual cues appearing on the skin surface in time to prevent them:xxv,xxvi injury deeper in the tissue is the suspected cause. If surface ulceration is hard to detect, identifying injury deep in the tissue is near impossible without a method of interrogation.

The Bruin Biometrics Solution Bruin Biometrics, LLC (BBI) has created the SEM Scanner, a diagnostic medical device intended to objectively detect pressure-induced tissue damage beneath the skins surface and measure the progression both of wound development and healing. Conceived by Barbara Bates-Jensen, PhD, RN, CWOCN, FAAN, one of the worlds leading wound care experts, the SEM Scanner is a hand-held, portable device that noninvasively detects levels of subepidermal moisture (SEM), a biophysical marker that is correlated with pressure ulcer formation and healing.xxvii,xxviii BBI believes that early detection of pressure ulcer formation is the best form of prevention. The SEM Scanner introduces an evidence-based, objective, method to pressure ulcer detection, enabling early intervention to treat tissue damage, and ultimately, prevent pressure ulcers.

38%

32%

13%

37% 39%

41%

6% 7% 11%

6% 7%

13%

5% 6% 9% 9% 9%

13%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Light Medium Dark

Stage I

Stage II

Stage III

Stage IV

Eschar

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Endnotes i European Pressure Ulcer Advisory Panel and National Pressure Ulcer Advisory

Panel, 2009. Prevention and Treatment of Pressure Ulcers: Clinical Practice Guidelines. Washington, DC: National Pressure Ulcer Advisory Panel.

ii Bates-Jensen, B., 2012. Pressure ulcers, Comprehensive Wound Care Review Course. Clinical Symposium on Advances in Skin and Wound Care: The Conference for Prevention and Healing.

iii Sussman, C. and Bates-Jensen, B. 2012. Wound care. Philadelphia: Wolters, Kluwer, Lippincott, Williams & Wilkins Health.

iv Lindan, O., Greenway, R.M. and Piazza, J.M., 1965. Pressure distribution of the surface of the human body. Arch Phys Med Rehabil, 46, pp. 378-385.

v Vangilder, C., Macfarlane, G., Meyer, S. and Others. 2008. Results of nine international pressure ulcer prevalence surveys: 1989 to 2005. Ostomy Wound Management, 54 (2), p. 40-54.

vi Vangilder, C.M., Amlung, S., Harrison, P. and Meyer, S. 2009. Results of the 2008-2009 International Pressure Ulcer prevalence Survey and a 3-year, acute care, unit-specific analysis. Ostomy Wound Management, 55 (11), pp. 39-45.

vii Marois, C.L., 2010. Pressure Ulcer Reduction and Elimination. Covidien. Available at: [Accessed 29 August 2013].

viii The Joint Commission Perspectives on Patient Safety Strategies for Preventing Pressure Ulcers, 2008. Strategies for Preventing Pressure Ulcers 8, pp. 57.

ix Agency for Healthcare Research and Quality (AHRQ). Preventing pressure ulcers in hospitals: A toolkit for improving quality of care. Available on: [Accessed 1 July 2013].

x Dealey, C., Posnett, J. and Walker, A. 2012. The cost of pressure ulcers in the United Kingdom. Journal of Wound Care, 21 (6), pp. 261-266.

xi Brem, H., Maggi, J., Nierman, D., Rolnitzky, L., Bell, D., Rennert, R., Golinko, M., Yan, A., Lyder, C. and Vladeck, B. 2010. High cost of stage IV pressure ulcers. The American Journal of Surgery, 200 (4), pp. 473-477.

x Allman, R., Laprade, C., Noel, L., Walker, J., Moorer, C., Dear, M. and Smith, C. 1986. Pressure sores among hospitalized patients. Annals of Internal Medicine, 105 (3), pp. 337-342.

xiii National Pressure Ulcer Advisory Panel, 2007. NPUAP pressure ulcer stages/categories, (online) Available at: [Accessed 15 November 2012].

xiv Bluestein, D. and Javaheri, A. 2008. Pressure ulcers: prevention, evaluation, and management. American family physician, 78 (10), pp. 1186-1194.

xiii Merckmanuals.com. 2013. Pressure Ulcers: Merck Manual Professional. [online] Available at:

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[Accessed: 30 Aug 2013].

xvi Thomas D.R., Rodeheaver G.T., Bartolucci A.A., Franz, R.A., Sussman, C., Ferrell, B.A., Cuddigan, J., Slotts, N.A., and Maklebust, J., 1997. Pressure ulcer scale for healing: Derivation and validation of the PUSH tool. Adv Wound Care, 10(5), pp.96-101.

xvii National Pressure Ulcer Advisory Panel. The facts of reverse staging in 2000, (online) Available at: < http://www.npuap.org/wp-content/uploads/2012/01/Reverse-Staging-Position-Statement > [Accessed 19 November 2012].

xviii Black, J.M., Edsberg, L.E., Baharestani, M.M., Langemo, D., Goldberg, M., McNichol, L., Cuddigan, J. and the National Pressure Ulcer Advisory Panel, 2011. Pressure ulcers: avoidable or unavoidable? Results of the National Pressure Ulcer Advisory Panel consensus conference. Ostomy Wound Management, 57(2), pp. 2437.

xix Mattie, A. S., & Webster, B. L. Centers for Medicare and Medicaid Services never events: an analysis and recommendations to hospitals. The health care manager, 27(4), pp. 338349.

xx Wounds-uk.com. 2013. Zero tolerance approach results in reduced pressure ulcer incidence News Wounds UK. [online] Available at: [Accessed: 30 Aug 2013]

xxi Schoonhoven L. (1998) Incidentie Van Decubtius Op de Operatietafel (Incidence of Pressure Ulcers at the Operating-room). Universiteit Utrecht, Utrecht.

xxii Halfens, R., Bours, G. and Van Ast, W. 2001. Relevance of the diagnosis stage 1 pressure ulcer: an empirical study of the clinical course of stage 1 ulcers in acute care and long-term care hospital populations. Journal of Clinical Nursing, 10 (6), pp. 748-757.

xxiii Kottner, J. and Dassen, T., 2010. Pressure ulcer risk assessment in critical care: Interrater reliability and validity studies of the Braden and Waterlow scales and subjective ratings in two intensive care units. International Journal of Nursing Studies, 47(6), pp. 671-677.

xxiv Thomas, D.R., 2001. Issues and dilemmas in managing pressure ulcers. J Gerontol Med Sci, 56, pp. 238-340.

xxv Bethell, E., 1992. Controversies in classifying and assessing grade 1 pressure ulcers. Nursing Times 99, pp. 7375.

xxvi Quintavalle, P. R., Lyder, C. H., Mertz, P. J., Phillips-Jones, C. and Dyson, M., 2006. Use of high-resolution, high-frequency diagnostic ultrasound to investigate the pathogenesis of pressure ulcer development. Advances in Skin Wound Care 19, pp. 498505.

xxvii Bates-Jensen, B., McCreath, H.E., Pongquan, V., and Apeles, N.C.R., 2007. Sub-Epidermal Moisture Differentiates Erythema and Stage I Pressure Ulcers in Nursing Home Residents. Wound Repair and Regeneration, 16, pp. 189-197.

xxviii Harrow J.J. and Mayrovitz H.N., 2006. Initial assessment of tissue water content surrounding pressure ulcers in spinal cord injury patients. [Abstract]. Available at: <

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ttp://clinsoft.org/drmayrovitz/POSTER-ABSTRACTS/23.html> [Accessed 29 August 2013].

xxxii Ncbi.nlm.nih.gov. 2006. ABC of wound healing: Pressure ulcers. [online] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1382548/ [Accessed: 30 Aug 2013].

xxxiii Lin, V., Cardenas, D., Cutter, N., Frost, F., Hammond, M., Lindblom, L., Perkash, I., Waters, R., Woolsey, R., Priebe, M. and Others, 2003. Principles of Pressure Ulcer Management. Demos Medical Publishing.