Abstract: Objective  To observe the effect of Praecoxib sodium combined with continuous positive airway pressure(CPAP) on pulmonary shunt and oxygenation in patients with esophageal cancer undergoing radical resection, and to explore the protective effect of Praecoxib sodium on pulmonary function. 
Methods  A total of 60 patients undergoing thoracoscopic and laparoscopic radical esophagectomy for esophageal cancer were randomly assigned to the observation group(n=30) and the control group(n=30). The observation group was given parecoxib sodium and the control group was given saline. Both groups were given CPAP. The duration of operation, duration of one-lung ventilation(OLV) and extubation time were compared between two groups. The PaO2 and PaCO2 were measured before induction of anesthesia(T1), 30 min after OLV(T2) and 30 min after recovery of two-lung ventilation(T3), and the intrapulmonary shunt rate(Qs/Qt) was calculated. 
Results  There was no significant difference in duration of operation, duration of OLV and extubation time between two groups(P＞0.05). The PaO2 decreased initially and increased afterwards in two groups. PCO2 and Qs/Qt showed a trend of initial increasing and then decreasing. The difference of interaction between groups, time points and time points between groups were statistically significant with respect to PaO2 and Qs/Qt. The difference of interaction between groups, and time points between groups were statistically significant in terms of PCO2(P＜0.05). 
Conclusion  For esophageal cancer patients undergoing radical resection, the combination of Parecoxib sodium and CPAP can reduce intrapulmonary shunt, improve PaO2, and help prevent the occurrence of hypoxemia. 

Key words: esophageal neoplasms； Parecoxib sodium, continuous positive airway pressure