A. Definition

1. Localized area of soft-tissue injury
2. Resulting from compression between a bony prominence and an external surface
3. Normal Stages of Wound Healing [3]
   1. Inflammation
   2. Tissue Formation
   3. Tissue Remodelling
4. Pressure ulcers appear to arrested in inflammatory / proliferative phases

B. Staging [1]

1. Useful for selecting therapy and reporting prevalence
2. Before Stage 1, tissue subject to pressure will exhibit blanching erythema
   1. This is due to capillary congestion
   2. This will resolve within 2 to 24 hours after pressure is relieved
3. Stage 1
   1. Nonblanchable erythema with intact skin
   2. Caused by extravasation of blood with tissue damage
4. Stage 2
   1. Partial-thickness skin loss
   2. Epidermis is interrupted by an abrasion, blister, or shallow crater
5. Stage 3
   1. Full-thickness skin loss with damage and/or necrosis
   2. May extend to the fascia but not beyond
6. Stage 4
   1. Full thickness skin loss with damage and/or necrosis
   2. Extends to muscle, bone, or supporting structures (tendons, joint capsule)

C. Epidemiology

1. 17-37% of patients have ulcers when transferred from an acute hospital to a nursing home
2. Prevalence among nursing home residents is 7 to 23%
   1. Prevalence has doubled over the past 10 years
   2. Number of discharges for older persons is decreasing
3. Prevalence at each stage among nursing home residents with ulcers
   1. Stage 1: 24%
   2. Stage 2: 41%
   3. Stage 3: 22%
   4. Stage 4: 13%
4. Common Ulcer Sites/Percent of ulcers at site among patients with ulcers
   1. sacrum or coccyx/36%
   2. hips (over trochanter)/17%
   3. buttocks (over ischium)/15%
   4. heels/12%
   5. ankles (over malleolus)/7%
   6. other/13%

D. Causes

1. Pressure
   1. In canine trials, levels as low as 60 mm Hg applied for 1 hour were capable of producing reversible tissue changes
   2. Supine humans generate heel to bed pressure of 50 to 94 mm Hg.
2. Friction - rubbing of one body against another, resulting in tissue abrasions or tears
3. Shear
   1. stress from applied pressure causing one body to slide on another
   2. May occur when a patient is brought to a seated position
   3. Skin stays stationary but body moves
   4. May result in bent or torn blood vessels and subsequent tissue ischemia

E. Risk Factors

1. Immobility
   1. Limited ability to sense the need to reposition self
   2. Sensation may be impaired because of disease or chemical restraints
   3. Limited ability to reposition self because of disease or mechanical restraints
   4. Combination of a and c above
2. Malnutrition
   1. Manifested by poor dietary intake, especially low protein intake.
   2. Manifested by inability to feed oneself
   3. If a or b are present, then biochemical markers of malnutrition may be unreliable
   4. These markers include serum albumin, vitamin C levels, transferrin level
3. Fecal Incontinence
4. Older patients are at higher risk than younger patients
5. Nonwhite patients are at risk because pre-Stage 1 and Stage 1 ulcers may be less visible
6. When multiple risk factors exist, patients are at greater risk for developing pressure ulcers

F. Prevention [5]

1. Prevention is strongly preferred over need for treatment
2. Prevention is based on modification of risk factors
3. Reduce pressure - most important risk factor
   1. Patient or caregiver should reposition patient every 15 minutes
   2. Static pressure reducers (support surfaces) include 4-6 inch solid foam mattresses: thicker is better,solid is better than convoluted
   3. Water bed may be best but is impractical in many settings
   4. Dynamic pressure reducers include low air loss beds, oscillating and kinetic beds
   5. Foam mattresses are least expensive and may be more effective for may patients
   6. Oscillating and kinetic beds are useful for patients with spinal cord injuries
   7. Cushions are available for chairbound patients - selection should be customized
4. Reduce shear and friction
   1. Maintain bed at lowest elevation possible given patient's medical condition
   2. Install trapeze or use a bed sheet for repositioning and moving patient
   3. Skin moisturizers may reduce friction
5. Maintain adequate nutrition - add supplements if patient borderline
6. Fecal Incontinence
   1. Manage fecal incontinence aggressively
   2. This avoids seeding ulcers with fecal bacteria

G. Treatment

1. Stage 1
   1. Aggressive management is critical to prevent progression
   2. Minimize pressure, shear and friction as above
   3. Correct malnutrition, increase protein consumption, supplement vitamin C
   4. Manage fecal incontinence
   5. Polyurethane dressing may be applied to further reduce friction and protect ulcer from bacterial contamination but permit gas exchange and water vapor escape
2. Stage 2
   1. As for Stage 1, but polyurethane dressing applied
   2. Avoid saline wet-to-dry dressings because of cost and may remove healing tissue
   3. Assess patient discomfort and provide pain management if necessary
3. Stage 3
   1. Reduce pressure, shear and friction, and add the following
   2. Debride necrotic tissue or eschar
   3. Small areas may be debrided by primary care physician; larger areas should be debrided by a surgeon
   4. Debridement may produce bacteremia - consider prophylactic antibiotics for patients with implanted prosthetic devices and for immunocompromised patients
   5. Wet-to-dry saline dressings may be used to debride loose material but are not recommended for use after debridement is complete - may remove healing tissue
   6. Use polyurethane or hydrocolloid dressings for shallow wounds
   7. For deeper wounds, pack with absorbent material - hydrophilic foam, alginates, saline- impregnated gauze. Change material daily, ensuring it is moist when changed to avoid removing healing tissue
   8. Consider using a low-air-loss bed , especially if patient is expected to recover
   9. Low-air-loss beds are probably not beneficial or cost-effective for terminal patients and patients with poor prognoses
   10. Pressure ulcers may be very painful - provide adequate pain management
4. Stage 4
   1. As above for Stage 3, and consider the following
   2. Debridement should be performed by a surgeon
   3. Consider grafting procedures in context of patient's preferences and expected outcome
5. Nerve Growth Factor (NGF) [4]
   1. Topical NGF for severe, noninfected pressure ulcers of the foot
   2. NGF group had reduced ulcer area 738mm2 versus 485mm2 at 6 weeks

References

1. Lyder CH. 2003. JAMA. 289(2):223
2. De Araujo T, Valencia I, Federman DG, Kirsner RS. 2003. Ann Intern Med. 138(4):326
3. Bello YM and Phillips TJ. 2000. JAMA. 283(6):716
4. Landi F, Aloe L, Russo A, et al. 2003. Ann Intern Med. 139(8):635
5. Reddy M, Gill SS, Rochon PA, et al. 2006. JAMA. 296(8):974