Pressure Injuries During Prone Ventilation

Prone positioning is an established component in the management of moderate-to-severe acute respiratory distress syndrome (ARDS). Although aimed at improving oxygenation and survival, turning a critically ill, mechanically ventilated patient in the prone position introduces its own complications. Among the most common are pressure injuries, particularly involving anatomical areas that are not ordinarily exposed to sustained pressure in the supine position. But which patients are at the greatest risk for pressure injuries, and how frequently do pressure injuries occur despite ICU prevention practices? In this Concise Critical Appraisal, we review the article by Felder-Minder et al who examined the incidence, location, and risk factors for pressure injuries among prone patients with ARDS from COVID-19.¹

The investigators performed a retrospective single-center cohort study in a 42-bed ICU at a Swiss tertiary university hospital. Adult patients with COVID-19 ARDS who underwent invasive mechanical ventilation and therapeutic prone positioning between March 2020 and February 2023 were eligible. Of 223 patients with COVID-19 ARDS, 147 required mechanical ventilation and 132 underwent prone positioning. Twenty-seven patients were excluded because photographic documentation of pressure injuries was unavailable, leaving 105 patients for analysis.

In the patient cohort, the median age was 65 years, 74% were male, mean BMI was 30.4 kg/m², and the median Simplified Acute Physiology Score (SAPS) II was 52. Of the 105 patients, 80% had at least one comorbidity. Patients underwent a median of three prone-positioning sessions, although some underwent as many as 26 sessions. Importantly, these patients were not placed prone without a structured prevention strategy already in place. The strategies included prone sessions lasting up to 16 hours; alternating-pressure mattresses with dedicated cushions beneath pressure-sensitive areas; hourly head micro-positioning; and arms, pelvis, and lower extremity repositioning every two to four hours. Skin was assessed before and after each session and kept dry. Proning itself was performed by an interprofessional team involving three to four nurses and a physician. The study protocol intentionally avoided routine head rotation because of concern for endotracheal tube displacement and instead used hourly micro-positioning. Thus, the study provides an opportunity to examine pressure injury development despite a relatively intensive and standardized prevention protocol.

Felder-Minder et al found that 40 (38.1%) patients developed at least one pressure injury, accounting for 71 injuries overall.¹ Of the affected patients, 86% had category II pressure injuries. There were no category IV or unstageable pressure injuries recorded. Unlike the sacral and heel distribution typically encountered in critically ill supine patients, most of the pressure injuries occurred on the face, including the chin (32.4%), forehead (21.1%), and cheeks (9.9%). Identifying the face as an important target may guide future preventive strategies, including optimized cushioning, prophylactic dressings, and improved pressure-distribution devices. Therefore, while repositioning remains a core prevention strategy, even frequent repositioning by a specialized interprofessional team did not eliminate pressure injuries in this high-risk cohort. This suggests that additional preventive measures, such as specialized dressings and targeted skin surveillance, may require greater consideration in patients who require repeated prone positioning.

Notably, the risk of pressure injury increased substantially with repeated prone sessions. Compared with patients undergoing fewer prone sessions, those receiving 5 to 7 sessions had a 5.9-fold greater risk of pressure injury, while those receiving more than eight sessions had a 7.6-fold greater risk. The authors also found that patients who developed pressure injuries had longer ICU stays (24.1 vs 15.3 days) and longer durations of mechanical ventilation (15.3 vs 10 days). Mortality was also higher among patients who developed pressure injuries (50% vs 36.9%). However, these patients also had more prolonged critical illness, longer mechanical ventilation, greater cumulative immobility, and a higher chance for pressure injuries to develop.

One important limitation is that patients who improve quickly or die early undergo fewer prone sessions and simply have less time to develop a pressure injury. In contrast, patients with more severe or prolonged ARDS are likely to be placed in the prone position more often and remain in the ICU longer, allowing pressure injuries more time to develop. Therefore, while repeated prone sessions were strongly associated with pressure injuries, we cannot assume that proning itself was the reason for the increased risk. More importantly, this should not discourage us from using a potentially lifesaving therapy in patients with severe ARDS. Instead, repeated prone sessions should alert us to patients at particularly high risk and prompt greater attention to skin surveillance, positioning, and protection of vulnerable pressure points.

In conclusion, pressure injuries remain common during prone ventilation despite careful preventive measures, particularly with repeated prone sessions and at vulnerable facial pressure points. The number of prone sessions may provide a simple bedside reminder of when greater attention is needed for skin surveillance, positioning, and additional protective measures. Ultimately, the goal is not to choose between protecting the lungs and protecting the skin, but to improve the procedure for both.



Reference

1. Felder-Minder S, Morgen-Ludwig A, Amrein M, et al. Incidence of pressure ulcers in ICU patients with ARDS positioned in the prone position: a retrospective single-centre cohort study. J Tissue Viability. 2026;35(3):101012.