NDNQI Training Module 1
shear - ✔️✔️Shear stress is the force (per unit area) exerted parallel to the tissue.2
Shear strain is the actual distortion or deformation of tissue as a result of shear stress.
Some shear strain occurs at rest. Shear strain is intensified in certain clinical situations
(e.g., raising the head of the bed > 30 degrees; dragging rather than lifting while
repositioning). One layer of tissue slides over another deforming adipose and muscle
tissue and disrupting blood flow.
pressure - ✔️✔️the force (per unit area) exerted perpendicular to the skin surface.2
Pressure damages the skin and underlying tissues by (1) directly deforming and
damaging tissue; (2) compressing small blood vessels hindering blood flow and nutrient
supply and (3) through ischemia-reperfusion injury. When pressure is redistributed over
a greater surface area, the pressure is less intense in any one area.
unstageable - ✔️✔️when the extent of tissue damage is obscured by slough or eschar
Deep tissue pressure injury (DTPI) - ✔️✔️in the process of evolution
mucosal membrane injuries - ✔️✔️should not be staged
stage 1 pressure injury - ✔️✔️Intact skin with a localized area of non-blanchable
erythema, which may appear differently in darkly pigmented skin. Presence of
blanchable erythema or changes in sensation, temperature, or firmness may precede
visual changes. Color changes do not include purple or maroon discoloration; these
may indicate deep tissue pressure injury.
blanchable - ✔️✔️Skin blanches with pressure. Color returns immediately with release.
non-blanchable - ✔️✔️No blanch, persistent redness in lightly pigmented skin.
Nonblanchable erythema - ✔️✔️is a defined area of redness that persists (does not
blanch/become pale) when pressure is applied to the area.
pressure injury - ✔️✔️localized damage to the skin and underlying soft tissue usually
over a bony prominence or related to a medical or other device. The injury can present
as intact skin or an open ulcer and may be painful. The injury occurs as a result of
intense and/or prolonged pressure or pressure in combination with shear. The tolerance
of soft tissue for pressure and shear may also be affected by microclimate, nutrition,
perfusion, co-morbidities and condition of the soft tissue.
shear - ✔️✔️Shear stress is the force (per unit area) exerted parallel to the tissue.2
Shear strain is the actual distortion or deformation of tissue as a result of shear stress.
Some shear strain occurs at rest. Shear strain is intensified in certain clinical situations
(e.g., raising the head of the bed > 30 degrees; dragging rather than lifting while
repositioning). One layer of tissue slides over another deforming adipose and muscle
tissue and disrupting blood flow.
pressure - ✔️✔️the force (per unit area) exerted perpendicular to the skin surface.2
Pressure damages the skin and underlying tissues by (1) directly deforming and
damaging tissue; (2) compressing small blood vessels hindering blood flow and nutrient
supply and (3) through ischemia-reperfusion injury. When pressure is redistributed over
a greater surface area, the pressure is less intense in any one area.
unstageable - ✔️✔️when the extent of tissue damage is obscured by slough or eschar
Deep tissue pressure injury (DTPI) - ✔️✔️in the process of evolution
mucosal membrane injuries - ✔️✔️should not be staged
stage 1 pressure injury - ✔️✔️Intact skin with a localized area of non-blanchable
erythema, which may appear differently in darkly pigmented skin. Presence of
blanchable erythema or changes in sensation, temperature, or firmness may precede
visual changes. Color changes do not include purple or maroon discoloration; these
may indicate deep tissue pressure injury.
blanchable - ✔️✔️Skin blanches with pressure. Color returns immediately with release.
non-blanchable - ✔️✔️No blanch, persistent redness in lightly pigmented skin.
Nonblanchable erythema - ✔️✔️is a defined area of redness that persists (does not
blanch/become pale) when pressure is applied to the area.
pressure injury - ✔️✔️localized damage to the skin and underlying soft tissue usually
over a bony prominence or related to a medical or other device. The injury can present
as intact skin or an open ulcer and may be painful. The injury occurs as a result of
intense and/or prolonged pressure or pressure in combination with shear. The tolerance
of soft tissue for pressure and shear may also be affected by microclimate, nutrition,
perfusion, co-morbidities and condition of the soft tissue.
