Objective:To investigate the difference effects in intrapulmonary shunt and pulmonary dynamic compliance between sufentanil-propofol by target-controlled infusion and isoflurane during one-lung ventilation.Methods:Twenty ASA ⅠorⅡ patients undergoing radical esophagus cancer resection via left thoracotomy were randomly divided into 2 equal groups(n=10 each):the sufentanil and propofol group(SUF) and the isoflurance group(ISO).In SUF group anesthesia was maintained with TCI of sufentanil and propofol(targeting effect-site concentration was set at 0.5 ng/ml and 3(g/ml);In ISO group

anesthesia was maintained with isoflurance.Arterial and pulmonary blood gases were analyzed 30 min after TLV was started(T0)

and 30

60

90 min after OLV was started(T1

T2

T3).The intrapulmonary shunt fraction(Qs/Qt) and pulmonary dynamic compliance(Cdyn) was calculated at T0-T3.Results:The PaCO2 and pH were within normal range in both groups.Qs/Qt was significantly increased while PaO2 and Cdyn was significantly decreased during operation(from T1 to T3)as compared to baseline values(T0)

but Qs/Qt decreasing while PaO2 was increasing from T2-T3 in both groups.Qs/Qt was significantly lower in SUF group than in ISO group at each interval(T1-T3)

Cdyn was significantly high in SUF group than ISO group at each interval(T1-T3)but there no significant difference in PaO2 at T2-T3 between the two groups.Conclusion:Compared with isoflurane anesthesia

there is less intrapulmonary shunt and high pulmonary dynamic compliance during OLV under general anesthesia with sufentanil-propofol

but the difference is not significant enough to affect PaO2.