Pressure Ulcers
Jennifer E. Marks, D.O.
February 25, 2004
LRI
Definition
of Pressure Ulcer
• An area of unrelieved pressure over a
defined area, usually over a bony
prominence such as the sacrum
• Pressure leads to ischemia, cell death, and
tissue necrosis, as capillaries are
compressed and the blood flow is restricted
• Muscle is the most sensitive tissue to
pressure, skin is the most resistant
How do pressure ulcers usually
present?
• 1. High pressure over bony prominence (can be a
single insult)
• 2. At muscle and bone interface, ischemia results.
• 3. Affected area with erythema, induration,
warmth, and skin is intact
• 4.Days to weeks s/p insult, EVEN WITH
PRESSURE RELIEF, the wound opens, and is a
depression with necrotic tissue
Pressure ulcers
•
•
•
•
Associated with :
1. Shear forces
2. Impaired sensorium/sensation (SCI patients!)
3. Poor nutrition- serum albumin positively
correlates with pressure ulcer stage, and
negatively correlates with risk
• 4. Chronic illness
• 5. Elevated tissue temperature- Higher metabolic
demands
• 6. Maceration
SCI patients
• Increased risk for pressure ulcer formation
• Estimated incidence 25-66%
Pathomechanics
• Shear forces- Tangential to the skin surface. Can
play a major role in the formation of sacral ulcers.
• Axial forces- Perpendicular to the skin surface.
Unrelieved axial pressure 4-6 times the systolic
pressure can cause necrosis in less than 60
minutes!
• If tissue capillary pressure is exceeded , ulcers will
form at that site.
How much pressure is too much?
• Kosiak 1961- Studied the effects of pressure
and time on rat muscle.
• More pressure=less time for an ulcer to
form
• Found that alternating pressure of as little as
5 minute intervals led to considerably less
ulcer potential.
• Kosiak’s research led to the current practice
of turning patients every two hours.
• Why don’t we measure pressure/shear as
clinicians?
– Transducers are thick , bulky, and expensive
– Shear transducers have not been modified for
clinical use
What is a safe amount of
pressure?
• Studies by Landis et al. have led clinicians
to believe that pressures under 32 mm Hg
are generally believed safe
• This value is influenced by tissue stiffness,
tissue composition, and the patient’s body
contour
Clinical Wound Assessment
• 1. Color photography- Use ruler in picture
to give dimensions. Very useful when done
in a serial fashion. An alternative is to draw
pictures of the wound.
• 2.Location- Be specific.
• 3.Size- Be sure to include length, width, and
depth measurements, in centimeters.
Clinical Wound Assessment
• 4. Describe the type of irrigation utilized,
and the dressing type.
• 5.Drainage:
– Amount(minimal, moderate, copious)
– Color (serous, serosanguinous, prurulent)
– Odor(present, absent)
Clinical Wound Assessment
• 6. Undermining/tunneling – Present/absent
• 7. Wound character- What kind of tissue? Is
there granulation, slough?
• Stage the ulcer
• IF THERE IS ESCHAR PRESENT, YOU
CANNOT STAGE THE WOUND!
Clinical Wound Assessments
Stage I
Nonblanchable erythema not resolved
in 30 minutes, epidermis intact
reversible with intervention
Stage II
Partial thickness loss of skin involving
the epidermis, possible into dermis
Stage III
Full thickness destruction through
dermis into subcutaneous tissue
Stage IV
Deep tissue destruction throgh
subcutaneous tissue to fascia, muscle,
bone
Systemic Conditions associated
with chronic wounds
SCI
Elderly
DM
B/B alterations,
contractures,
spasticity,denervation
atrophy,insensitivity
Reduced skin elasticity,
altered skin
microcirculation
Insensitivity,
microangiopathy
Treatment
•
•
•
•
Sharp debridement
Mehanical nonselective debridement
Enzymatic Debridement
Autolytic debridement
Sharp debridement
• Removal of devitalized tissue/eschar via surgical
means. Small wounds can be debrided at bedside,
more extensive wounds can be addressed in the
OR
• Most effective/quickest method of removing
necrotic tissue. Debridement is done to the point
where the tissue bleeds with forceps and a scalpel.
• Must have the clinical skill/judgement necessary
to be able to discern the difference between
vitalized and nonvital tissue.
• Cons: Can damage healthy tissue
Mechanical nonselective
debridement
• Whirlpool
• Irrigation
• Wet to Dry dressing- utilize normal saline,
place moist gauze on the wound, let dry.
– When the dressing is removed, the necrotic
tissue comes off it.
– Cons: Healthy tissue can be damaged
Wet to Dry vs. Wet to Moist
• Saline wet to dry dressings are used to
debride necrotic wounds
• Wet to moist dressings maintain a clean
moist wound bed and are removed before
they dry out.
• Wet to moist dressings have to be changed
more frequently
Enzymatic Debridement
• Utilizes chemical agents (such as
Accuzyme) in the form of ointments which
work on the necrotic wound debris, and do
not affect the viable tissue
Autolytic debridement
• The bodies own enzymes break down dead
tissue.Wound cells secrete proteases, collagenases
that digest eschar. Hydrocolloid dressings help to
promote this type of debridement.
• Pros: Very effective in noninfected wounds- an
occlusive dressing allows wound fluid to collect
• Cons: If the wound is infected, you have just
created an abcess!
Wound dressings
•
•
•
•
•
Gauze
Transparent adhesive dressings
Hydrocolloid dressings
Gel dressing
Calcium alginate dressings
Transparent adhesive dressings
•
•
•
•
Ex. Tegaderm, Opsite
Semipermeable, occlusive
Stage I/II wounds without debris
Allow gaseous exchange/water vapor
transfer from the skin, prevent peri-wound
maceration
• Do not use if wound is exudative or the
patient is diaphoretic
Hydrocolloid dressings
• Ex. Duoderm
• Interact with wound exudate , and make a
gel
• Keep wound surface moist.
• Enhances healing, protects versus secondary
infection
• Help to minimize shear
– Good for shallow stage III sacral ulcers
Calcium alginate dressings
• Made from brown seaweed (ex. Sorbsan),
sterile
• Semi-occlusive, highly absorbable
• Good for treating exudative or contaminated
wounds
• Need to be frequently changed
Most common pressure ulcer
sites
• Ischium 28%
• Sacrum 17-27%
• Trochanter 12-19% (Bears weight when
patient is in a sitting position)
• Other commonly affected sites include
coccyx, heel, and malleolus
Treatment
•
•
•
•
Proper medical care
Turn patient Q 2 hours
Frequent dressing changes
Proper nutrition- High protein diet indicated as a
high amount of protein is lost through the wound
• Pressure relief in wheelchair, specialty support
surfaces
• Continued wound assessment
Support surfaces
• Include overlays (water, gel , foam, air)
• Specialty beds
– Low air loss beds (Flexicare)have cushions
filled with air that keep pressures below the
capillary closing pressures
– Air fluidized beds (Clinitron) use warm air
forced through silicone beads to mimic a fluid
medium
Which support surface is best?
• No study has shown conclusively that one
surface performs better than the others!
• Must individualize your approach
• If a patient has a Stage III or IV ulcer, the
patient should be utilizing a pressure relief
product
Wound Infection
• Presentation: Foul odor, greenish drainage, dull
white base (versus red granulation tissue). Can
have cellulitis, with erythema, warmth, swelling,
tenderness.
• Systemic bacteremia: Chills, anorexia,
nausea/vomiting, fever, increased white count,
mental status changes, glucose intolerance in
diabetics.
• Signs of bacteremia/cellulitis- IV abx/possible
debridement
Wound cultures
• Should not be routinely performed, as the cultures
will always be positive
• Exception- If antiseptic such as Betadine is used
prior to local debridement, and an abcess or other
sequestered collection is exposed
• Occasionally, cultures are taken for burn wounds
• Greater than 105 CFU’s- wound will not heal
When are topical antibiotics
indicated for pressure ulcers?
• If a pressure ulcer does not heal after 2-4
weeks of optimal treatment, can try silver
sulfadiazine or triple antibiotic ointment x
2-3 weeks
Osteomyelitis
• Must keep in mind , especially with a Stage
IV pressure ulcer or if ulcer over a bony
prominence
• 25% of nonhealing ulcers have bone
infection
• Gold standard- Bone biopsy
• Imaging- XRay, MRI
Xray
• Reactive bone formation and periosteal
elevation =osteomyelitis
• BONE SCANS ARE A POOR STUDY TO
DETECT OSTEOMYELITIS! High false
positive rate.
MRI
• 95% sensitive
• On T2 weighted image, can demonstrate
marrow edema
• Can reveal soft tissue abnormalities such as
perirectal fistulas
Why don’t we just close the
wound (vs. using flap)?
• Usually not enough soft tissue
• Too much tension where the incision site
would be
Musculocutaneous flaps
• Why use a muscle flap when muscle is the
first tissue to become ischemic?
– Minimizes “deadspace”, and provide tissue
with rich vasculature
– NOT being used as a cushion!
– In less than a year, the flap usually atrophies,
but the blood supply remains intact
– Also, the surgeon can put the suture line away
from the maximal pressure area
When are flaps indicated?
• Better for an SCI patient , or when muscle
loss will not affect ambulatory ability
• Not as easy a decision in an ambulatory
patient, where function can be compromised
Best treatment for a pressure
ulcer?
•
•
•
•
NO ONE RIGHT ANSWER! Keep in mind:
1. PREVENTION
2. Must correct the underlying problem
3. Wounds must be cleaned/ dead tissue
removed before healing can occur
• 4. Keep wound moist- Permits cells to
perform migration/mitosis
What is being researched?
• Electrical stimulation – some studies are
showing improved pressure ulcer healing
rate in chronic stage III and IV ulcers
– Controversial
– Also small study using growth factors in SCI
patients.
– Both areas need more research
Works Cited
Braddom, Randall L. Physical Medicine and
Rehabilitation. Second Edition.
Philadelphia, Pennsylvania. W.B. Saunders
Company, 2000.
O’Young, Young, et al. Physical Medicine and
Rehabilitation Secrets. Second Edition.
Philadelphia, PA. Hanley & Belfus Inc.,
2002.