Pressure injuries

Identification of the correct stage of a pressure injury is critical in documentation in any medical setting. The next posts will illustrate and describe the different stages for pressure injuries, as well as discuss wounds that are often staged inappropriately as pressure injuries.
Pressure injuries

The pressure injury in the attached photograph would be categorized as:

  • Unstageable
  • Stage 3
  • Stage 4
  • Deep tissue injury


Answer: D

The NPUAP guidelines for staging pressure injuries defines deep tissue pressure injury (DTPI) as follows:

Persistent non-blanchable deep red, maroon or purple discoloration Intact or non-intact skin with localized area of persistent non-blanchable deep red, maroon, purple discoloration or epidermal separation revealing a dark wound bed or blood filled blister. Pain and temperature change often precede skin color changes. Discoloration may appear differently in darkly pigmented skin.  This injury results from intense and/or prolonged pressure and shear forces at the bone-muscle interface.  The wound may evolve rapidly to reveal the actual extent of tissue injury, or may resolve without tissue loss. If necrotic tissue, subcutaneous tissue, granulation tissue, fascia, muscle or other underlying structures are visible, this indicates a full thickness pressure injury (Unstageable, Stage 3 or Stage 4). Do not use DTPI to describe vascular, traumatic, neuropathic, or dermatologic conditions. [i]

The pathophysiology of DPTI is not totally understood; however, it is widely accepted that shear or pressure forces at the bone/muscle interface result in capillary destruction, bleeding into the interstitial tissue, tissue necrosis, and discoloration that is eventually visible at the dermal level, but without loss of the epidermis/dermis tissue.  There may be some blistering of the epidermis that occurs with the discoloration, but the skin remains intact.  If the causes of the mechanical forces are removed and the patient has controlled blood sugars and adequate nutrition, DTPIs may resolve without becoming an open pressure ulcer.  However, the injured tissue and skin may become necrotic, deeper anatomical structures such as muscle or fascia may be involved, and the patient may have impaired healing for a myriad of reasons; at this point the DTPI would be restaged according to the guidelines that will be discussed in futures posts.

The first treatment strategy for any pressure injury is to determine the cause of the tissue’s mechanical deformation and to eliminate the cause as much as possible.  Adjunctive treatments that have been shown to be helpful, especially in preventing the DTPI from progressing, include non-contact low-frequency ultrasound[ii] and silicone-backed foam dressings.[iii]  Appropriate management of comorbidities and adequate nutrition for healing are also imperative in both the prevention and treatment of DTPIs.

iNational Pressure Ulcer Advisory Paney. NPUAP Pressure Injury Stages. 2016.  Accessed August 4, 2019.

iiWagner-Cox P, Duhame HM, Jamison CR, Jackson RR, Fehr ST.  Use of noncontact low-frequency ultrasound in deep tissue pressure injury: a retrospective analysis.  Journal of Wound, Ostomy and Continence Nursing. 2017;44(4):336-342.  doi: 10.1097/WON.0000000000000342

iii Strauss R, Preston A, Zalman DC, Rao AD.  Silicone foam dressing for prevention of sacral deep tissue injuries among cardiac surgery patients.  Advances in Skin and Wound Care.  2019;32(3):139-142.


Additional information about pressure injuries/ulcers is available at:

Garcia AD, Sprigle S. Pressure injuries and ulcers. In Hamm R (Ed), Text and Atlas of Wound Diagnosis and Treatment: 2nd edition.  New York: McGraw Hill Education.  2019, 171-198.  Available at