Univariate analysis showed that age (P = 0.028), CIRS (P = 0.002), vasopressor use (P = 0.037), preoperative albumin levels (P = 0.038), length of hospital stay (P = 0.018), rSO2 at T1 (P = 0.003), rSO2 at T4 (P < 0.001) and postoperative TΔrSO2% (P = 0.002) were significantly associated with postoperative delirium. The gene discussed is ALB; the disease is delirium.