Prognostic Value of Pulse Oximetry Differences

This prospective observational study aims to evaluate whether the difference between finger, earlobe and forehead SpO₂ (ΔSpO₂) measured at emergency department (ED) presentation is associated with clinical outcomes in adult patients presenting with dyspnea. We will compare ΔSpO₂ between patients with poor outcomes (death or intensive care unit \[ICU\] admission) and those with favorable outcomes. Secondary objectives include assessing the prognostic value of ΔSpO₂ for mortality, ICU admission, and lactate, and comparing its predictive performance with established early warning scores.