Arterial Blood Gas Levels, Oxygen Saturation, and Pressure Injury Risk in ICU Patients

Pressure injuries are defined as localized damage to the skin and/or underlying soft tissue caused by prolonged pressure and/or shear forces, and they most commonly occur over bony prominences (Han et al., 2025). In intensive care patients, these injuries lead to serious consequences such as pain, risk of infection, prolonged hospital stay, and mortality (Labeau et al., 2021). In critically ill patients, inadequate tissue perfusion and oxygenation are identified as one of the main pathophysiological mechanisms involved in the development of pressure injuries (Han et al., 2025). Hypoxia, which occurs when cells are unable to meet their metabolic needs, reduces tissue tolerance and adversely affects the healing process. While insufficient oxygen inhibits collagen synthesis and cellular regeneration, it also reduces blood flow by causing vasoconstriction (Lucchini et al., 2024). This causes tissues in areas exposed to pressure to be more easily damaged.

Therefore, monitoring oxygenation levels is critically important in predicting the risk of pressure injury development. Han et al. (2024) demonstrated that as PaO₂ levels decrease, the risk of pressure injury increases significantly, and that this relationship is supported by a nonlinear dose-response curve. On the other hand, it has been suggested that oxygen saturation may be a more reliable indicator than PaO₂, and that the risk may increase up to sixfold at low oxygen saturation levels (Rahimi-Bashar et al., 2025).

In this context, this study aims to evaluate the relationship between arterial blood gas parameters - pH, PaO₂, PaCO₂, and HCO₃- - and oxygen saturation (SpO₂) levels and the risk of pressure injury development in intensive care patients from the perspective of nursing care.

Inclusion criteria

• Patients who have been hospitalized in the intensive care unit for at least 72 hours,
• Patients aged 18 years and older,
• Patients who are conscious or sedated and from whom an arterial blood gas sample can be obtained,
• Patients or their relatives who agree to participate in the study.

Exclusion criteria

• Patients with superficial skin lesions or existing pressure injuries, or a history of pressure injuries,
• Patients whose intensive care unit stay is shorter than 72 hours,
• Patients diagnosed with diabetes,
• Patients with circulatory problems.