| Objective To find suitable fraction of inspired oxygen (FiO2) for thoracic surgery patients with one-lung ventilation, we compared the effects of different FiO2on intrapulmonary shunt rate(Qs/Qt), oxidative stress response and postoperative recovery in the patients undervent lung cancer radical surgery.Methods76cases ASA Ⅱ or Ⅲ patients undergoing lung cancer radical surgery were randomly divided into five groups according to the difference FiO2after starting one lung ventilation(OLV):group A(n=17), FiO2=100%, group B(n=16), FiO2=60%, group C(n=16), FiO2=50%, group D(n=19), FiO2=40%, group E(n=7), FiO2=30%. Each group was general anaesthesia induced by50%FiO2. The FiO2was changed to the target oxygen concentration after starting one lung ventilation:FiO2was increased to100%in group A, FiO2was increased to60%in group B, FiO2was maintained to50%in group C, FiO2was decreased to40%in group D, FiO2was reduced to30%in group E. When the patients transfered into the thoracic surgical ICU,the FiO2was adjusted to50%again.Observation indexes:(1)SpO2:The change of pulse oxygen saturation(SpO2) was observed at any time.If the SpO2<90%occur,the experimental study was immediately terminated.(2)The blood gas analysis and oxidative stress indexes:The radial artery and right atrial blood of all patients were withdrew for blood gas analysis and calculation of intrapulmonary shunt fraction [Qs/Qt=(CcO2-CaO2)/(CcO2-CvO2)] and respiratory index [RI=P (A-a) O2/PaO2)] in following time points:before starting one lung ventilation (T1), before recurring two-lung ventilation (T2), after two-lung ventilation30minutes and thoracic cavity was closed (T3),2hours after the operation (T4); The radial artery blood5ml was used to determinate plasma superoxide dismutase (SOD) and lipid peroxidation products malondialdehyde (MDA).(3)Postoperative recovery indicators:Recording the incidence of postoperative wound site infection, the incidence of patchy consolidation showed on chest X-ray at3rd day after operation and the days of postoperative hospital stay.Results:(1)The incidence of SpO2<90%:Every patient in group E appeared SpO2<90%after one-lung ventilation10～15min.The incidence of SpO2<90%was100%. The experiment were terminated in all patients of group E; The incidence of SpO2<90%in group E was significantly higher than that in group A, B, C, D (P<0.001); There were no significant difference between group A, B, C, D (P>0.05).(2)The indexes of blood gas analysis:①Lactic acid:There were not significant difference between group A, B, C, D at any time point (P>0.05); The lactic acid values of all groups were in the normal range (<2.5mmol/L);②Oxygenation index (PaO2/FiO2):When compared with the T1, PaO2/FiO2of group A, B,C and D was significantly lower at the T2(P<0.05); however, PaO2/FiO2of C and D groups was significantly higher in the T4(P<0.05). There were no significant difference between group A, B, C, D at the same time point (P>0.05);③Respiratory index(RI):Compared with the T1:RI of group A, B,C and D was significantly higher at the T2(P<0.05); however, RI of group C and D were significantly lower in the T4(P<0.05).Compared with group A:RI in group C decreased significantly at T2and T4(P<0.05).④Intrapulmonary shunt fraction (Qs/Qt):Compared with the T1:Qs/Qt in group A was significantly increased at T2(P<0.05); Qs/Qt in group B had no significant difference in all time points (P>0.05); Qs/Qt in group C was significantly lower at T4(P<0.05); Qs/Qt in group D was significantly lower at the T3and T4(P<0.05).At T1:There was no statistically significant difference between group A, B, C, D (P>0.05); At T2:Qs/Qt in group A was significantly higher than that in group B, C, D (P<0.01); At T3:Qs/Qt in group A was significantly higher than that in group B, C, D (P<0.01) and Qs/Qt in group B was higher than that in group D (P<0.05); At T4:Qs/Qt in group A was higher than that in group C and D (P<0.05).(3) Oxidative stress parameters:①superoxide dismutase (SOD):Compared with the T1:The SOD of groupA, B, C,D was not significant difference from T2to T4(P>0.05).Compared with group A:SOD in group C was significantly higher at T2(P<0.05); SOD in groupB, C, D was higher at T4(P<0.001).Compared with group B:SOD in group C was significantly increased at T4(P<0.05).②Malondialdehyde (MDA):Compared with the T1:MDA in group A and B had no significant changes in T2～T4(P>0.05); MDA in group C significantly decreased at T2～T4(P<0.05); MDA in group D decreased at T4(P<0.05).Compared with group A:MDA in group C decreased significantly at T4(P<0.05).(4) postoperative recovery index:①The incidence of postoperative wound site infection:There was no significant difference between group A, B, C, D (P>0.05).②The incidence of patchy consolidation showed on chest X-ray at3rd day after operation: The Incidence of patchy consolidation in group A and B were significant higher than that in group C and D (P<0.005);There was no significant difference between group A and B, There was no significant difference between groupC and D (P>0.05).③The days of postoperative hospital stay:The days of postoperative hospital stay in group A was significantly longer than that in group B, C, D (P<0.05); There were no significant difference between group B, C,D (P>0.05).Conclusions:1When FiO2is30%during one lung ventilation, the incidence of hypoxemia was100%.240%<FiO2<60%can reduce oxidative stress, improve the function of lung gas exchange, which is suitable low to moderate oxygen concentration during one-lung ventilation.FiO250%may be optimal inspired oxygen concentration for patients with one-lung ventilation.3The high oxygen concentration increase oxidative stress and Qs/Qt. So the pure oxygen should be avoided to use. If PaO2allowed, low to moderate inspired oxygen concentration should be used as far as possible.4, Low to moderate FiO2may reduce the postoperative pulmonary infiltration rate and shorten the time of hospitalization, but need a further study with large samples. |
PDF Full Text Request