A Clinical Study Of Different Pulmonary Expansion Manoeuvres After One Lung Ventilation In Pulmonary Lobectomy

Objective To compare effects of four different pulmonary expansion manoeuvres on pulmonary ventilation, respiratory mechanics and pulmonary function of postoperative in patients with lobectomy after one lung ventilation (OLV).Method Fourty patients with right lung lobectomy were randomly divided into four groups (A, B, C, D group, n=10).Patients were conducted with the following different pulmonary expansion manoeuvres after OLV:tidal volume (VT) of 8 ml/kg, VT 8 ml/kg with positive end-expiratory pressures (PEEP) 5 cmH2O, VT 12 ml/kg, VT 12 ml/kg with PEEP 5 cmH2O,respectively. Blood pressure (BP) and heart rate (HR) were detected after OLV(T1),40 minutes after OLV(T2), process of pulmonary expansion(T3),10 minutes (T4) and 30 minutes (T5) after pulmonary expansion.Observed the peak airway pressure (Ppeak), airway pressure platform (Pplat) and dynamic compliance (Cdyn) at T1, T2, T4 and T5. Recorded partial pressure of oxygen in artery (PaO2), Alveolar-arterial oxygen difference (P(A-a)O2),intrapulmonary shunt fraction (Qs/Qt) and the dead-space to tidal volume ratio (VD/VT) at T1, T2, T4,T5 and 50 minutes (T6) after pulmonary expansion. Assayed the PaO2 and P (A-a) O2 in conscious patients at 30 min (T7) after extubation. And pulmonary function were measured with patients on preoperative and 7 days postoperative,including percentage of predicted Forced Vital Capacity(FVC%pred), percentage of predicted forced vital expiratory volume in 1 second(FEV1%pred), percentage of FEVi/FVC ratio(FEV1/FVC%),percentage of predicted maximal mid expiratory flow (MMF%pred).Result There is no obvious change in BP and HR during operation(P> 0.05).Differences were not statistically significant in Ppeak, Pplat and Cdyn among the four groups and within groups (compared with T1) after pulmonary inflation(P>0.05). VD/VT was significantly lower at T4 when Group D was compared with Group A(P<0.05); PaO2 increased significantly at T4and T5 when Group D was compared with A and B groups, VD/VT at T5 was decreased obviously,P(A-a)O2 was significantly lower at T4 and T6,and Qs/Qt reduced significantly when T6 (P<0.05); differences were significant on PaO2 and VD/VT at T6 when Group D was compared with the other three groups (P< 0.05); VD/VT of Group D reduced significantly at T4,T5and T6 when compared with T1 (P<0.05).Compared with group D, PaO2 at T7 showed a significant difference (P<0.05). But, no significant difference was found in P(A-a)O2 among the groups. FVC%pred、FEV1%pred、MMF%pred in patients after 7 days operation were significantly decreased when compared with preoperative (P< 0.05), FEV1/FVC% had reached preoperative level (P>0.05).The lung function index in 7 days postoperative was no statistical significance among the groups(P>0.05).Conclusion Pulmonary expansion with VT 12 ml/kg and PEEP 5 cmH2O was given by standard weight may improve pulmonary ventilation after one lung ventilation, but had little effect on respiratory mechanics and postoperative pulmonary function.