ABSTRACT
Objective To study the effect of sevoflurane pretreatment or aftertreatment on intrapulmonary shunt for patients with one lung ventilation(OLV)during thoracic surgical procedures .Methods 80 ASA I or II patients underwent thoracic surgery with OLV were randomly divided into four groups(n= 20 for each):(1)Propofol group(group P);(2)Sevoflurane pretreatment group(group S1);(3)Sevoflurane aftertreatment group(group S2);(3)Sevoflurane whole-treatment group(group S3) .Blood sam-ples were taken from radial artery and right atrial blood before induction of anesthesia(baseline T .0) ,before OLV(sevoflurane pre-treatment 30 min ,T1) ,after OLV 30 ,60 min and before the end of OLV(T2-T4)and after the end of OLV(T5)for measurement of blood gases and calculation of Qs/Qt .The indexs of hemodynamics and relative clinical data were recorded .Results Arterial oxy-gen pressure of the four groups for OLV significantly reduced ,when compared with double lung ventilation(P0 .05) .Intrapulmonary shunt of the four groups for OLV significantly in-creased ,when compared with double lung ventilation(P 0 .05) .Conclusion Sevoflurane can decrease intrapulmonary shunt for patients during OLV ,but there is no significant difference for pretreatment or af-tertreatment or whole treatment and do not increase arterial oxygen pressure .