When determining pseudoexudates, a serum-pleural effusion albumin gradient (SPAG) of >1.2 g/dL and a serum-pleural effusion protein gradient (SPPG) of >3.1 g/dL together showed a sensitivity of 100% in heart failure and a sensitivity of 99% in hepatic hydrothorax [10]. Here, ALB is linked to heart failure.