As I contemplate the current conversation around ventilators, I am encouraged to refresh my knowledge about mucosal pressure injuries. Pressure injuries on the mucous membranes present and are staged differently from cutaneous pressure ulcers, and they are usually attributed to a medical device or tube. Nasogastric or orogastric tubes, oxygen cannulas or masks, endotracheal tubes, and urinary and fecal containment devices pose a risk of causing local ischemia to tissue in the nose, mouth, genitals, or rectum, respectively.

Once a mucosal injury occurs, the patient is at increased risk of other problems, including pain, infection (especially if injury occurs to the urinary tract), and even malnutrition, if pain from oral wounds makes it difficult to eat and drink. These hospital-acquired pressure injuries contribute to the physical burden on the patient, as well as the financial burden on the hospital because they do count as a nosocomial—and usually, preventable—ulcer.

Mucosal Anatomy

Unlike skin, many of the mucosal surfaces do not contain keratinized epithelium (excluding the masticatory mucosa and the dorsum of the tongue.¹ The connective tissue layer (lamina propria) connects this stratified squamous epithelial layer to the submucosa. The layers of tissue are so thin and so similar that it would be too difficult to tell by visual inspection which layer is exposed.² Furthermore, structures such as muscle or bone would not be present in an injury localized to the mucosa. Because of these differences, we cannot rely on the traditional partial-thickness/full-thickness staging system to classify a mucosal pressure injury as a numeric stage.³ For instance, nonblanchable erythema would not be present inside an oral cavity as it would manifest on a sacral stage 1 pressure injury. What may appear as slough in a mucous membrane wound is actually a soft blood clot created by the clotting cascade, also known as "coagulum," and it may manifest as yellow, shiny, flat, and loosely attached to the wound bed.⁴ Additionally, these areas typically do not form a scar from the remodeling process, possibly because of different activity of their fibroblasts, which more closely resemble fetal fibroblasts.⁴

Medical Device-Related Pressure Injury: Creating a Culture of Prevention

Wound Treatment and Prevention

Unfortunately, there is a shortage of research on best practices for mucosal pressure injuries. Medical-grade honey has shown some promise in oral ulcers of other etiologies.⁵ Topical corticosteroids are often used to reduce inflammation and pain associated with infectious oral ulcers.⁶ Any topical treatment or antiseptic rinse would have to be shown to be safe because of the risk of absorption by the mucous membranes and the likelihood of ingestion of medications placed in or around the mouth. Reduction of mucosal pressure injuries, as with all medical device–related injuries, lies in the importance of proper assessment, early detection, and pressure prevention using stabilizing devices, tube holders, cushions, and padding on the patient and/or the device itself to reduce or prevent contact between the device and the tissue.

Takeaways

As seems to be the theme with wound care, "an ounce of prevention is worth a pound of cure." Consider revising oral care and critical care "bundles" to include prevention strategies, for instance, adding use of tube stabilizers to any devices that can be suspended off the skin, or use of a barrier dressing on areas that cannot be totally offloaded. It is also important (and often forgotten) to inspect the skin underneath the stabilizing device according to manufacturer recommendations or hospital policy. If your facility participates in bedside rounding, that time during shift hand-off would be optimal for both nurses to move the medical device and inspect the mucosal tissue for injury.

Educate the entire team about the differences among these types of pressure injuries—so many team members are involved with mucosal health without even realizing it.

A nursing assistant performing catheter hygiene may notice a urinary catheter awkwardly pulling on the patient and may correct the tension; the nurse assessing cranial nerves through tongue movement may be the first to spot a wound in the oral cavity; the respiratory therapist may spot the risk from an improperly secured endotracheal tube; and speech and occupational therapists can identify a patient who is "cheeking" food on one side and discover why it is painful to chew on the other side of the mouth. So many staff members have an opportunity to identify risk, implement preventative measures, and detect symptoms early, so we can continue to reduce the risks associated with our devices and interventions.

References

1. Groeger S, Meyle J. Oral mucosal epithelial cells. Front Immunol. 2019;10:208. https://www.frontiersin.org/articles/10.3389/fimmu.2019.00208/full. Accessed June 30, 2020.

2. Michigan Histology and Virtual Microscopy Learning Resources. Oral cavity. University of Michigan Medical School. https://histology.medicine.umich.edu/resources/oral-cavity. Accessed 22 May 2020.

3. Edsberg LE, Black JM, Goldberg M, McNichol L, Moore L, Sieggreen M. Revised national pressure ulcer advisory panel pressure injury staging system. J Wound Ostomy Continence Nurs. 2016; 43(6): 585-597. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5098472/. Accessed June 30. 2020.

4. National Pressure Injury Advisory Panel. Mucosal pressure ulcers: an NPUAP position statement. NPUAP; 2008. https://cdn.ymaws.com/npuap.site-ym.com/resource/resmgr/position_statem…. Accessed June 30, 2020.

5. Simon A, Traynor K, Santos K, Blaser G, Bode U, Molan P. Medical honey for wound care – still the'latest resort'? Evid Based Complement Alternat Med. 2009;6(2): 165-173. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2686636/#B48. Accessed June 30, 2020.

6. Weinberg MA, Segelnick SL. Management of common oral sores. U.S. Pharmacist. 2013;38(6):43-48. https://www.medscape.com/viewarticle/807035_1. Accessed June 30, 2020.

About the Author

Lauren graduated with a BSN from the University of Buffalo in Western New York, where she was born and raised. She has held various nursing jobs, but continued to work towards a goal of a career in wound care nursing after she was one of only two students who signed up for a wound care clinical during nursing school. She currently works at the Advanced Wound Healing Center in Orchard Park, NY where she once had her nursing clinicals. She became credentialed in Wound, Ostomy, and Continence Nursing in 2019 and is incorporating her knowledge and skills into her busy clinic practice. When not at work, Lauren enjoys indoor spinning, playing guitar, video games, and rooting for the Buffalo Bills NFL team.