CRP and Pleural effusion: The results indicated that the occurrence of AKI was related to the duration of hospitalisation and to the presence of pleural effusion, α1-microglobulin, urine microalbumin, urine transferrin, urine NAG, the neutrophil ratio and the levels of haemoglobin, CRP and serum IgM (P < 0.05), as shown in Table 4.