The unavoidable pressure injury/ulcer: a review of skin failure in critically ill patients.

Due to an ageing population and prolonged lifespan, pressure injury (PI) incidence is increasing. Patients with a PI typically endure longer hospital stays, which create a significant burden on healthcare resources and costs. With appropriate preventive interventions, most PIs can be avoided; however, skin failure may become inevitable in particular instances. These are classified as unavoidable PIs. Patients in a critical condition are exposed to a unique set of therapies, medications and bodily states. Oftentimes, these instances decrease tissue tolerance, which may promote PI formation. Patients who are critically ill, especially those with extended stays in the intensive care unit, are susceptible to skin failure due to: prolonged immobility; mechanical ventilation; acute respiratory distress syndrome; COVID-19; sepsis; multiorgan system dysfunction; vasopressor use; and treatment with extracorporeal membrane oxygenation. Poor perfusion leading to skin breakdown results from the compounding factors of circulatory collapse, build-up of metabolites, compromised lymphatic drainage, patient comorbidities, and ischaemia via capillary blockage in patients who are critically ill. In addition, similar physiology is present during end-of-life multisystem organ failure, which creates unavoidable skin deterioration. The aim of this review is to provide an overview of circumstances which decrease tissue tolerance and ultimately lead to PI development, despite adequate preventive measures in patients who are critically ill.