Figure 1

Effect of ulinastatin on respiratory index. Respiratory index (RI) in the ulinastatin group (U) was significantly lower than that in the control group (C) 1 hour after one-lung ventilation (T₂) and the time of sternal closure (T₃; P < 0.05). The RI was calculated as a marker of lung damage using the following formulas: RI = [F_{IO 2} × (760–47) - Pa_{CO 2}/0.8]/Pa_{O 2}.