Effects of ulinastatin on airway oxidative stress and pulmonary function in patients undergoing cardiac surgery

Objective To study the effect of ulinastatin on airway oxidative stress and pulmonary function in patients undergoing cardiac surgery.

Methods A total of 42 patients who underwent elective cardiac valve replacement under extracorporeal circulation were selected, and were randomly divided into ulinastatin group and control group, with 21 patients in each group. The ulinastatin group was given 15 000 IU/kg ulinastatin to the preflush, while the same amount of normal saline was added in the control group. Exhaled breath condensate fluid was collected immediately after tracheal intubation (T₀), immediately after cease of cardiopulmonary bypass (T₁), chest closure (T₂) and 4 h after operation (T₃), and the concentration of 8-isoprostaglandin F2 alpha (8-isoPGF_2α) was detected. The fraction of the oxygen in the inspired air (FiO₂), tidal volume (V_T) and other indicators were recorded and were performed blood gas analysis. The oxygenation index, alveolar artery oxygen partial pressure difference p_A-a(O₂) and respiratory index (RI) were calculated. Postoperative follow-up was performed to observe the extubation time of tracheal catheter, intensive care duration, postoperative hospital stay, the occurrence of postoperative pulmonary complications (PPCs) or other adverse reactions.

Results The levels of 8-isoPGF_2α in exhaled breath condensate fluid of both groups were significantly increased after cardiopulmonary bypass, and were significantly lower at T₁, T₂ and T₃ in the ulinastatin group than those in the control group (P < 0.05). The oxygenation indexes at T₁, T₂ and T₃ of the ulinastatin group were higher than that of control group, the levels of p_A-a(O₂) at T₁ and T₂ were lower than that of control group, and the RI at T₂ was lower than that of control group, the differences were statistically significant (P < 0.05). The incidence of PPCs was 20.00% in the ulinastatin group, which was lower than 57.89% in the control group (P < 0.05). The time to postoperative extubation was earlier, and the time of intensive care was shorter than that of the control group (P < 0.05).

Conclusion Ulinastatin may improve oxygenation and pulmonary function by reducing airway oxidative stress in patients undergoing cardiac surgery, reduce the occurrence of PPCs, and shorten the postoperative extubation time and intensive care duration.