Pressure Ulcers Flashcards
What is a pressure ulcer?
A localized area of tissue necrosis that develops when soft tissue is compressed between a firm surface and underlying bony prominence
What are the 3 classes of patients with the greatest risk of developing a pressure ulcer?
- Individuals with spinal cord injuries
- Hospitalized patients
- Individuals in long-term care facilities
Pressure ulcers can develop in less than _ hours if the proper conditions prevail
2
Describe the etiology behind pressure ulcers
1) Pressure on any given bony prominence is transmitted to underlying tissues, compressing all structures in between.
2) When the applied pressure is greater than the intracapillary blood pressure, blood flow to soft tissue is obstructed and local tissue ischemia occurs.
3) The pressure also restricts local lymphatic channels which leads to higher concentrations of metabolic wastes and acidosis.
4) If pressure is maintained, capillary permeability increases as does local edema and inflammation.
5)
Ischemia causes a decrease in fibrinolysis which leads to what?
fibrin deposits within capillaries and interstitial space
In patients with pressure ulcers, fibrinolytic activity at the wound border is significantly less than _ mm away
9
Previously it was thought that there was a critical level of pressure, below which no ulceration would occur. What is that pressure?
less than 32 mmHg
No longer believed to be true
What 4 individual hemodynamic factors affect the amount of pressure needed to cause a pressure ulcer?
- hematocrit
- RBC flexibility
- blood viscosity
- lower temps
Is muscle or bone more sensitive than skin to the effects of ischemia due to pressure? Explain why…
muscle, because the greatest pressure occurs in the tissue directly over the prominence
Pressure ulcers may not develop until - days after the pressure was applied. Why?
2-7
Because trauma occurs from the inside out
Relief of short-term pressure is followed by blood rich in oxygen and nutrients to flood the ischemic tissues and remove waste products from the area. What is this called and what does it look like?
Reactive hyperemia, a localized area of blanchable erythema
What is the length of time reactive hyperemia lasts proportional to?
the extent of tissue ischemia
What are the 7 Risk Factors Contributing to Pressure Ulcers?
- Shear
- Excessive moisture
- Impaired mobility
- Malnutrition
- Impaired sensation
- Advanced age
- History of pressure ulcer
Shear occurs when a force is applied ____ to the soft tissue
parallel
What do pressure ulcers with a shearing component look like?
a teardrop appearance and undermining is common
When does friction occur?
When 2 surfaces move across one another
How does increased moisture predispose skin to pressure ulcers?
- Causing maceration
- Increasing shear
- Increasing friction forces
What are 3 things that maceration can be caused by?
- Wound drainage
- Perspiration
- Incontinence
Urinary incontinence has been shown to increase ulceration __-fold
five
What are the 3 factors that affect a patient’s mobility?
- affecting the ability to move (restricted ROM, limited strength, presence of mechanical devices)
- the desire of a patient to move or change positions (pain or depression)
- the ability to perceive pain (medications, neuron damage)
What are the 4 most frequently studied causes of impaired mobility with respect to pressure ulcer development?
- Hospitalization
- Fracture
- Spinal cord injury
- Infants/neonates
Malnutrition is the __ most common risk factor for development of pressure ulcers
2nd
Low levels of serum _____ causes interstitial edema and signals the body lacks the protein stores necessary for building and repairing tissues which predisposes the body for ulceration.
albumin
__% of patients with pressure ulcers are obese
53
True or False
Hydration plays a role on pressure ulcer development.
True
What are 6 examples of cases in which sensation may be impaired leading to an increased risk of pressure ulceration?
- Spinal cord injury
- Spina bifida
- Stroke
- Diabetes mellitus
- Full-thickness burns
- Peripheral neuropathy
More than half of patients with pressure ulcers are over __ years old
70
Describe why previous pressure ulcers increase the risk of future pressure ulcers
Because the scar tissue that developed can only attain up to 80% of the strength of the original tissue. This alters tolerance to pressure and externally applied loads
Low diastolic blood pressures, particularly those less than __ mmHg, may develop pressure-related tissue damage from forces lower than expected or in a shorter period of time.
60
How often should a pressure ulcer risk assessment tool be administered in each of the following settings: home health, acute, long-term care?
Home health: every visit
Acute care: every 48 hours
Long-term: every week for the first month
What are 3 of the most widely used and researched assessment tools?
- Braden Scale for Predicting Pressure Sore Risk
- Norton Risk Assessment Scale
- Gosnell Pressure Sore Risk Assessment
What are the 6 subscales of the Braden scale?
- mobility
- activity
- sensory perception
- skin moisture
- nutritional status
- friction and shear
Scores on the Braden scale range from _-__, with lower scores indicating _____ impairment and _____ risk
6-23
greater
higher
A score less than __ on the Braden scale is deemed an at-risk patient
18
Pressure ulcer risk assessment for pediatric patients can be performed using the Braden _ scale
Q
A score less than __ on the Braden Q scale is deemed an at-risk patient
16
On the Norton Risk Assessment Scale if a patient scores less than or equal to __ they are considered at risk
16
What is the problem with the Norton scale?
It may over predict the incidence of pressure ulcers
Higher scores on the Gosnell Pressure Sore Risk Assessment indicate ______ impairment and ____ risk
greater
higher
On the Gosnell scale if a patient scores greater than __ they are considered at risk
16
What are the 5 arms of pressure ulcer prevention?
- education
- positioning
- mobility
- nutrition
- management of incontinence
Patients should not be placed directly on their side, rather a __ degree lateral position should be used
30
For every gram decrease in serum albumin levels below normal, the odds of having a pressure ulcer increase __fold
four
What does the mnemonic NO ULCERS stand for?
- Nutrition and fluid status
- Observation of skin
- Up and walking or assist with position changes
- Lift, don’t drag
- Clean skin and continence care
- Elevate heels
- Risk assessment
- Support surfaces