Unusual Presentation of Deep Tissue Injuries: A Case Series

Deep tissue injuries (DTIs) are the manifestation of multiple layers of tissue necrosis and are often secondary to chronic mechanical stress to an area of bony prominence. The prevalence of these injuries among the chronically ill and patients in long-term care require a strong understanding of their etiology and a highly sensitive identification algorithm. Although the National Pressure Ulcer Advisory Panel (NPUAP) has released new guidelines with accurate descriptions as to how these injuries present, there is a significant segment of patients that present atypically and, as such, the treatment plan and prognosis are difficult to predict based on physical presentation, which can lead to either delays in necessarily aggressive care or conversely an overzealous treatment plan in hopes of addressing a pathology that may be self-limiting. Three cases of patients with a DTI, in which the initial presentation was not typical (ie, as described by the current NPUAP staging system) and not an accurate diagnostic predictor of prognosis, are presented. These differences, their course of treatment, and a more comprehensive diagnostic approach will be discussed in the hopes of more accurately identifying these injuries with a focus on prediction of disease trajectory.

Deep tissue injuries (DTIs), defined by the National Pressure Ulcer Advisory Panel (NPUAP) as areas of “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,”¹ unfortunately are a common occurrence that often manifest during the treatment of chronically bed-bound patients or those who are temporarily limited in their mobility secondary to some form of trauma with spinal cord injury, stroke, or other stillness. These injuries are usually found in areas where a bony prominence bares the weight of the patient in a supine or seated position. There are 4 general causative factors that precede a DTI: (1) chronic mechanical deformation of tissue cells; (2) reduced lymphatic drainage leading to local accumulation of waste products and tissue toxic enzymes; (3) reperfusion injury, caused by the return of blood flow to previously ischemic tissue and the subsequent damage done by the products of the inflammatory response to the initial ischemia (observed in crush injuries)¹; and (4) local vascular constriction with capillary occlusion typically in areas exposed to a position dependent on pressure and containing a bony prominence.

The clinical presentation of these types of injuries is most obvious in the late stage when necrosis is well demarcated and the ulcer has been debrided.² The disparity in vascular distribution with respect to the different tissue types offers an explanation as to why the color change and nonblanchable nature of the involved area of skin are late stage signs. Adipose tissue is relatively less vascular than the dermal layer and thus often succumbs to the effects of ischemia earlier than the skin.² The relative abundance of vascular supply enjoyed by the dermal layer allows it an extended symptom-free time, even though the mechanisms previously described are already causing damage to the dermis and underlying tissue.² This delay in severe clinical presentation most likely explains the variable nature of the diagnosis. Eventually, the mechanical stresses or prolonged ischemia cause necrosis in the skin, signaling the end of an inside-out process of ischemic damage.² The prognosis for these injuries ranges from possible resolution requiring no intervention after addressing the causative stress (ie, mechanical stress forces or compression of the local vasculature) to prolonged and intensive wound care, up to and including multiple debridements resulting in stage 4 injuries.

In addition to the morbidity costs to the patient with these types of injuries, the monetary costs incurred by health care systems caring for these patients must be acknowledged. The annual cost of treating DTIs is estimated to range from $9.1 billion to more than $28 billion for treating pressure ulcers in general.³ The per-patient cost to treat injuries that have progressed to stage 4 pressure ulcers or DTIs is estimated at an additional $100 000.³ These numbers do not include the costs of addressing lawsuits that stem from this injury type, which are the second-most common claim for wrongful death.³ Annually, about 60 000 patients die from complications of DTIs of iatrogenic cause.³ Although prevention and early intervention are clearly the objectives of any wound care plan, the question of whether a wound requires or will require treatment is an important decision to make. Oftentimes, providers will initiate treatment based on institutional standards, published algorithms, or practice experience.^3,4 While each of these positions has merit, a more concrete diagnostic approach with a high predictive value with respect to prognosis and treatment effectiveness would be a welcome addition to the standard of care.

This case series of DTIs, in which the initial presentation was not typical (as per the current NPUAP staging system) and was not an accurate diagnostic predictor of prognosis, will approach these differences, their course of treatment, and a more comprehensive diagnostic approach in the hopes of more accurately identifying these injuries with a focus on prediction of disease trajectory.

The 3 reported cases were referrals from acute hospitals to the authors’ long-term acute care (LTAC) facility in Dayton, Ohio. The products used throughout their respective treatment courses were industry standard and similar to what would be available in another facility of similar size and type. In line with that reasoning, the authors feel the relative lack of novelty with regards to treatment modality was important in isolating the disease pathology and the difficulty inherent in predicting an outcome based on physical appearance. They also feel this collection of cases is a fair cross section of this type of injury and reasonably representative of similar cases at large.

Case 1

A 37-year-old man 2-weeks post motor vehicle accident (MVA), with rib fractures and left leg compartment syndrome post fasciotomy, presented to the LTAC facility with a DTI on the right lower buttock (Figure 1A). He complained of a painful lump in the DTI area; the indicated injury was not believed to be secondary to the MVA. A decision was made to not intervene but to observe the area closely for signs of worsening tissue breakdown along with offloading (2 hourly turning and use of low air loss mattresses).

After 3 weeks in LTAC with no surgical wound care interventions initiated, the wound resolved with no further complications (Figure 1B). Both the size of the lump and pain decreased. The decision to delay more aggressive interventions other than offloading and to maintain close observation of the area was made based on the clinical presentation only.

Case 2

A 67-year-old man with early-stage dementia, peripheral neuropathy, and difficulty ambulating presented to the outpatient wound clinic with a 1-week history of a painful right sacral/gluteal area with erythema and hyperpigmentation (Figure 2A). The area was covered with a protective foam dressing (Biatain Non-Adhesive Foam Dressing; Coloplast, Minneapolis, MN) and an air mattress was ordered for the patient’s home. He was instructed to remain on his left side when in bed.

The patient returned for 1-week follow-up and reported his symptoms had remained unchanged and that his pain level was increasing. He was taken to the operating room for wound exploration where a 5-cm incision from the sacrum to the right gluteal area revealed subcutaneous fat necrosis extending to the right gluteal fascia that included a thin flap of muscle. Following sharp debridement, the wound was irrigated with normal saline and packed with a wet dressing (Dakin’s solution quarter-strength wet and moist daily dressing change). The dressing was changed once daily for 7 days and then treatment was changed to negative pressure wound therapy (NPWT; V.A.C. Therapy; KCI, an Acelity Company, San Antonio, TX) at -125 mm Hg continuous fashion for 8 weeks.

The patient was seen at the clinic 1-week postoperatively (Figure 2B) where wound healing with increased granulation tissue was visible.

Figure 2C shows the wound 2 months after surgery; at that time, he reported no pain and his wound was healing well with utilization of previously described NPWT.

Two weeks later at 11-week postop follow-up, the wound completely healed with daily hydrogel dressing changes (used in the last 2 weeks of treatment).

Case 3

A 56-year-old woman with a history of chronic obstructive pulmonary disease presented to the emergency room with acute respiratory failure and was admitted to the intensive care unit with left upper lobe pneumonia. Following discharge, she was sent to the LTAC facility for intravenous antibiotics (intravenous vancomycin for MRSA pneumonia).

On admission, she was found to have a painful DTI on her right buttock (Figure 3A). Based on initial presentation, treatment was not initiated and the decision was made to observe her closely for signs of worsening tissue damage along with offloading via scheduled turning and low air loss mattress use.

Computed tomography (CT) scans (Figure 3B) revealed mild tissue ischemia with edema represented by hypoechoic areas but without active necrotic process to warrant immediate intervention.

At 1-month follow-up, the patient’s wound improved and reduced in size by half without surgical intervention with the help of aforementioned offloading (Figure 3C). She also reported a marked reduction in pain and discomfort.

At her outpatient follow-up 1 month later, the area of interest was nearly unrecognizable (Figure 3D).

The clinical presentation of DTIs can vary greatly. The etiology of the injury is most likely the largest contributor to the wound morphology. The costs, both in morbidity to patients and to hospitals caring for these patients, are significant.³ Therefore, the decision on whether to treat and aggressively address what could be a life-threatening emergency or observe and allow resolution if possible must often be made based on a somewhat incomplete picture. As cases 1 and 3 depict, relatively severe appearing wounds can often resolve if given proper support without the need for surgical intervention as seen in case 2, which was published previously as a case report.² Of special interest is the use of diagnostic imaging to aid in the staging and prognosis of these injuries.^5,6 Case 3 in this series included CT scans that were obtained upon admission and showed a low to moderate level of tissue damage; therefore, the decision to allow conservative treatment could be made with a degree of certainty after observing the current nature of the disease process.

Yabunaka et al⁵ report that studies have used other imaging modalities to predict the likelihood of a patient developing a DTI or pressure ulcer. Aoi et al⁶ used ultrasound to develop a predictable profile of patients likely to progress to DTI, unstageable injury, or pressure ulcer in a series of predictable and diagnostic results in patients who would later develop DTIs but had not shown obvious clinical signs. Of specific note was evidence of discontinuous fascia and hypoechoic areas. Their study⁶ also demonstrated that these injurious signs were not from shearing forces or from the deformation of tissue but from ischemia and subsequent tissue damage alone.

At present, there are several clinical circumstances in which standardized diagnostic imaging is being utilized to identify injuries that are still clinically unobservable.^5,6 The choice of imaging modality is best guided by the patient’s individual risk factors (ie, lifestyle, level of mobility, history of present illness) or the provider’s index of suspicion and available technology.

Long-wave infrared (LWIR) thermography is being used as an initial diagnostic tool for patients on admission to LTAC facilities. This tool provides an immediate image of the temperature differential in the area of interest and differentiates between areas of inflammation (increase in temperature from .25ºC to .9ºC) and ischemia (decrease in temperature from .2ºC to .5ºC). Due to its noninvasive nature, this tool can be used for serial evaluation to rule out a developing injury or to track the response to treatment.

The use of high-frequency harmonic ultrasound, another noninvasive imaging technique, is unique in that it allows the evaluation of both an injury and the pertinent vascular supply.^5,6 Changes in tissue elasticity are correlative with pathological progression of the wound. These changes are observable, because they distort the acoustic reflective properties of the tissue. However, the machine is cumbersome and requires the application of pressure on the involved area, which may cause pain.

Transcutaneous oximetry (TCOM) applies a laser diode to skin innervated by vasculature of questionable integrity. This modality evaluates the partial pressure of oxygen in the dermis layer of the skin that has diffused through capillaries. Although not an imaging technique, TCOM takes advantage of the skin’s low priority of tissue oxygenation in the context of vasculature insufficiency. A disturbance in tissue oxygenation and any subsequent ischemia will be quickly observable by a decreased oxygen partial pressure, but this modality is time consuming, not practical to perform on the floor, and usually reserved to the hyperbaric oxygen therapy department.

Fluorescence injection angiography is a more invasive method of vascular and end tissue evaluation but provides a definitive image of the patient’s current perfusion status. In addition to primary evaluation, it is currently in use for post procedure tracking of response to treatment following vascular interventions. This technology is time consuming and expensive.

The authors recommend patients who are identified as at risk of developing pressure ulcers (low Braden score) have the benefit of some form of imaging as standard of care in addition to a thorough physical evaluation on admission. After imaging has suggested the presence of previsual injury, the following steps can be followed to mitigate the disease process:

• Daily monitoring of the area of interest by a wound care service;
• Admission to a specialty floor, if indicated, and accommodations in a specialized bed with offloading products to reduce pressure on weight-bearing areas; and
• Implementation of a regular turning schedule by the nursing staff.

These interventions will preemptively direct treatment resources to patients most at risk. They also will create a documentation timeline for health care facilities in the hopes of decreasing the significant costs of addressing lawsuits for injuries that may have become clinically apparent during the course of their care but were ongoing upon presentation.

These cases demonstrate the variable presentation of DTIs and difficulties inherent to their diagnosis based on clinical presentation alone. There may be discontinuity between what is observable and the current clinical picture, and as much as 1 week can separate the time of injury and its obvious presentation. Avoiding delays in care is of paramount importance in addressing these injuries. Imaging such as CT scans, ultrasound, LWIR thermography, and others already are being used with predictable results.⁷ These modalities should be included in the standard of care for patients vulnerable to these types of injuries for early detection, prevention of further harm, and delivery of the most appropriate and expeditious care.

The authors thank Dr. Jeffrey Travers for his help in reviewing and editing the manuscript.

Michael Wilson, BS¹; and Richard Simman, MD, FACS, FACCWS^1,2

Affiliations: ¹Department of Pharmacology and Toxicology, Dermatology, Wright State University Boonshoft School of Medicine, Dayton, OH; and ²Wound Care Program, Jobst Vascular Institute, Promedica Health System, Toledo, OH

Correspondence: Richard Simman, MD, FACS, FACCWS, Clinical Professor, Plastic and Reconstructive Surgery, Jobst Vascular Institute, ProMedica Health System, Toledo Hospital, 2109 Hughes Drive, CJT Suite 400, Toledo, OH 45606; Richard.simmanmd@promedica.org

Disclosure: The authors disclose no financial or other conflicts of interest.