NPPB and Pleural effusion: Univariate analysis was performed in derivation cohort using the univariate logistic regression model and included the following 30 clinical parameters: age, elderly, sex, BMI, GCS, temperature, SBP, heart rate, RR, arterial pH, PaO2, AB, lactic acid, serum sodium, potassium, WBC, Hb, HCT, TBIL, SUA, eGFR, D-dimer, INR, NT-proBNP, hs-TNI, LVEF, PASP, existence of AF, pleural effusion and BBB.