Pressure Injury Management Flashcards
What is interface pressure?
Pressure exerted on the skin surface when in contact with a support surface (e.g holding a plank)
Greater body surface area= lower uniform pressure
Lesser body surface area= higher point pressure
What is a pressure injury?
A localised injury to the skin and/or underlying tissue usually over a bony prominence, as a result of pressure or pressure in combination with shear and/or friction
Discuss the aetiology of a pressure injury
-Vessel occlusion > tissue hypoxia > pallor > ischaemia > increased capillary permeability > accumulation of metabolic wastes/proteins in interstitial space > oedema > impairs tissue and perfusion > ischaemia = PI.
-Excessive or sustained compression of the vascular and lymphatic network
- compression of capillaries or micro circulation
-compression exceeds perfusion pressure and structural resistance of capillaries = oxygen and nutrient supply to tissue is compromised.
Results in localised ischaemia, hypoxia, acidosis, oedema and necrosis
What degree of pressure collapses capillary walls?
32mmhg - will vary among people depending on vessel structure, adipose deposition over bony parts, BP and general health
What are the common diets for pressure area injuries?
On side: Maleoli, shoulder, ear cartilage, trochanter, metatarsal
Sitting: scapular,sacrum, ischium,
On back: occiput, scapular, spinous process,heel, elbow, iliac crests
Name and describe the two mechanisms by which a pressure injury is caused?
Sheer: parallel pressure applied to sliding body against a non conform able surface causes tissue damage.
- distorts tissue causing two adjacent internal tissues to deform in transverse plane.
Friction: rapid or frequent movement against an abrasive surface
- rubbing of one surface against another ; or the force that resists the relative motion of two objects that are touching
What are the predisposing INTRINSIC risk factors for pressure injuries?
Pertains to the person
Alter the ability of skin and underlying tissue to resist pressure, shear, friction and compromises recovery.
Advanced age, immobility and inactivity, malnutrition, skin temperature and PH, chronic illness.
What are the predisposing extrinsic factors for pressure injury development?
Pertain to external environment
Increase susceptibility of skin to damage.
-pressure, shear and friction, moisture
Discuss how advanced age is a risk factor for pressure injuries
Deterioration of body function and healing potential
Loss of SC tissue, collagen production-assists with tissue support and production.
Impaired mobility and activity by physical, cognitive or neurological problems.
Poor nutrition or access to it - reduced immunity, poor tissue turgor, in elasticity of skin.
Discuss how immobility and activity are risk factors for pressure injuries
Affect ability to independently re-position and offload tissue.
Susceptible to shear and friction if assistance is required.
Impairs blood flow and retards venous return =oedema= compromises 02 of skin
Discuss how malnutrition effects pressure injury development
Balance diet optimises health,healing,immune response.
Obese people have poorly vascularised tissue due to excess adipose, capillaries vulnerable to shear
Obesity compromises movement
Cachexic people have bony parts with reduced tolerance for pressure.
Discuss how skin temperature and PH are a predisposing factor for pressure injuries
Skin provides protection and thermoregulation
Changes in skin temp are closely aligned to changes in core temp
One degree rise raises metabolic needs by 10%
PH of skin is acidic at 5.5ish -optimise microclimate
Microclimate = skin temp, humidity and moisture
Acidic minimises bacterial colonisation and opportunistic infection
Describe how chronic illness is a risk factor for pressure injuries
Diabetes, carcinoma, peripheral artery disease, CPD, lymphodoema, real/ hepatic impairment, HTN, anaemia
Smoking
Discuss pressure, shear and friction as risk factors for pressure injuries
Duration and magnitude of pressure= degree of damage
High pressure= damage in short time
Greater body surface = lower uniform pressure and vice versa.
Interface pressure- pressure exerted at the skin surface when in contact with a support surface.
When IP exceeds capillary closing pressure, damage occurs.
IP= body weight/ surface area supported
Shear and friction are interlinked
Discuss how moisture is a factor affecting pressure injuries
Tensile strength is impaired with frequent/excessive moisture
Maceration
Increase in skin temp ams humidity increase moisture amount