CRP and Decreased total leukocyte count: In previous studies, the principally reported negative prognostic factors for mortality during AECOPD cases admitted to an ICU were: a low mean arterial pressure (MAP); elevated blood urea nitrogen (BUN) [29]; an intubation event [29,30]; a lower value of SpO2 at admission 21; lymphocytes < 0.8 × 109/L; leukopenia; chronic heart failure [30,31]; older age, an initial C-reactive protein (CRP) >7.5 mg/dL; a peak eosinophil to neutrophil ratio (ENR) of >102; and in-hospital complications [32].