Effect of continuous low-to medium-flow oxygen administration in non-ventilated lung on oxidative stress response of lung tissues during one-lung ventilation / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of continuous low-to medium-flow oxygen administration in non-ventilated lung on the oxidative stress response of lung tissues during one-lung ventilation (OLV).Methods Fifty-seven American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients,aged 50-64 yr,weighing 40-74 kg,scheduled for elective pulmonary tumorectomy,were divided into 2 groups using a random number tablecontrol group (group C,n=29) and continuous oxygen administration group (group O,n =28).The patients were intubated with the double-lumen tube after induction of anesthesia.Correct position of the tube was verified with the fiberoptic bronchoscope.In group O,the F14 tube was placed at 2-3 cm beyond the carina of trachea in the non-ventilated lung at the beginning of OLV,and low-to medium-flow oxygen was continuously administered at 1-4 L/min with the fractional concentration of inspired oxygen set at 25％-37％.Blood samples were taken from the radial artery and internal jugular bulb at the beginning of anesthesia induction (T1) and 30 min,1 h and 2 h of OLV (T2-4) for blood gas analysis.Lung tissues at the site 5 cm lateral to the tumor were taken immediately after resection of diseased tissues for determination of superoxide dismutase and malondialdehyde levels (by chemical colorimetry) and heme oxygenase-1 expression (by Western blot).Results Compared with group C,the partial pressure of arterial oxygen was significantly increased at T2-4,the partial pressure of arterial carbon dioxide was decreased at T2,3,the partial pressure of venous oxygen was increased at T2,3,the partial pressure of venous carbon dioxide was decreased at T2-4,the malondialdehyde level was decreased,and the expression of heme oxygenase-1 was up-regulated (P＜0.05),and no significant change was found in superoxide dismutase level in group O (P＞0.05).Conclusion The mechanism by which continuous low-to medium-flow oxygen administration in non-ventilated lung exerts pulmonary protection is related to inhibiting oxidative stress responses of lung tissues during OLV.