摘要：The purpose of this study was to evaluate the effect of sivelestat sodium hydrate, a selective inhibitor of neutrophil elastase in the systemic inflammatory response, pulmonary function, and the postoperative clinical course following esophagectomy. Patients with hypoxia associated with surgical stress in the intensive care unit (ICU) immediately after an esophagectomy were eligible for this study. The degree of hypoxia was calculated according to the ratio of arterial oxygen tension (PaO(2)) to the fractional concentration of inspired oxygen (FiO(2))-PaO(2)/FiO(2). Patients with PaO(2)/FiO(2) < 300 mmHg were enrolled in this study. Seven patients were treated with sivelestat, and 10 were not so treated. The degree of hypoxia, the criteria for systemic inflammatory response syndrome (SIRS), and the postoperative clinical course were compared between the two groups. The postoperative decreases in the PaO(2)/FiO(2) ratio were significantly suppressed in the sivelestat group (p < 0.05, by analysis of variance, or ANOVA). Furthermore, 9 of the 10 control group patients developed SIRS on postoperative day 2, whereas only 2 of 7 of the sivelestat group patients developed SIRS (p < 0.05). The postoperative increases in the heart rate were significantly suppressed in the sivelestat group (p < 0.05, ANOVA). The postoperative decreases in the platelet counts were significantly suppressed in the sivelestat group (p < 0.05, ANOVA). The duration of mechanical ventilation and the length of ICU stay for the sivelestat group were shorter than that for the control group. We demonstrated that the postoperative decreases in the PaO(2)/FiO(2) ratio following esophagectomy were significantly suppressed in the sivelestat-treated group. This clinical study showed that a neutrophil elastase inhibitor may thus be a potentially useful drug for treating acute lung injury following esophagectomy.