单肺通气期潮气量对肺内分流及动脉氧合的影响

目的 研究单肺通气(OLV)时不同潮气量(V_T)对肺内分流及动脉氧合的影响.方法 60例右肺部分切除术患者随机均分为A、B、C三组.全麻后双肺通气(TLV)时V_T均为10 ml/kg,RR均为12次/分,吸呼比(I:E)均为1:2.OLV期间,A组V_T6 ml/kg,RR 20次/分;B组V_T 8 ml/kg,RR 15次/分;C组V_T 10 ml/kg,RR 12次/分;分别于OLV前(T_1)及OLV后10 min(T_2)、20min(T_3)、30 min(T_4)行血气分析,计算肺内分流(Q_S/Q_T),同时监测气道压力并计算肺顺应性(Cdyn).结果 与T_1时比较,T_2～T_4时三组均有PaO_2下降,Q_S/Q_T气道峰压(P_(max))增高,Cdyn下降(P<0.05).与A组比较,B组PaO_2升高(P<0.05).结论 OLV期间采用V_T 8 ml/kg,RR 15次/分能够维持相对较好的PaO_2和CAyn,较小的Q_S/Q_T.

Effects of tidal volume on arterial oxygenation and intrapulmonary shunt during one lung ventilation

Objective To investigate the effects of different tidal volume (V_T) on arterial oxygenation and intrapulmonary shunt(Q_S/Q_T) during one lung ventilation(OLV).Methods Sixty patients scheduled for selective lobectomy under left lateral decubitus position were randomly divided into groups of A,B and C with 20 cases each.After bronchial induction,two lung ventilation(TLV) was performed with V_T 10 ml/kg,frequency(f) 12 breaths per minute(BPM),ratio of inspiration to expiration(I: E) was 1:2 at first.During OLV,I: E was kept steady,V_T 6 ml/kg and f 20 BPM were chosed in group A,V_T8 ml/kg and f 15 BPM in group B,V_T 10ml/kg,f 12 BPM in group C.Blood gas analysis was determined before OLV (T_1) and at 10 min(T_2) ,20 min(T_3) ,and 30 min after OLV (T_4).Q_S/Q_T and lung complience(Cdyn) was calculated.Results OLV Compaired to T_1,PaO_2 and Cdyn were lower (P<0.05) and Q_S,Q_T and peak airway pression were increased (P<0.05).The decrease of PaO_2 was more in groups of A and C than that in group B(P<0.05).Conclusion During OLV,a better PaO_2.may be maintained with the ventilation parameters of V_T8 ml/kg and f 15 BPM with less increase in Q_S/Q_T and higher Cdyn.