title: [Effect of different tidal volume ventilations on atelectasis in patients during general anesthesia by CT scan].
abstract: OBJECTIVE
  To investigate the effect of different tidal volume ventilations on the amount of atelectasis during general anesthesia.
  
  
  METHODS
  Twenty adults, ASA physical status I and status II patients, who were scheduled for elective excision of intracranial lesion were randomly divided into 2 groups: Group TV (traditional tidal volume ventilation, 10 mL/kg) and Group LV (low tidal volume ventilation, 6 mL/kg). Atelectasis, as determined by CT and artery blood gas (ABG) analysis, was measured before the anesthesia, after the tracheal intubation, and at the end of the operation, respectively. Respiratory mechanical parameters were measured at 30, 120, and 240 min after the intubation.
  
  
  RESULTS
  After the tracheal intubation, CT scan showed obvious atelectasis in both groups. The atelectasis area was(4.35+/-2.15)cm2 (3.12%+/-1.94%) in the TV group and (4.80+/-2.45)cm2 (3.89%+/-2.11%) in the LV group, with a nonsignificant difference between the 2 groups. At the end of the operation, there was no significant increase in the amount of atelectasis between and within the 2 groups. Artery blood gas analysis showed no difference after the tracheal intubation and at the end of the operation in either group. Ppeak, Pplat, Pmean and lung compliance(Cst)were significantly higher in the TV group than those in the LV group.
  
  
  CONCLUSIONS
  Low tidal volume(6 mL/kg) ventilation is more feasible during general anesthesia in patients with healthy lungs, and it does not increase the atelectasis and impairment of gas exchange.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Xiangya Hospital, Central South University, Changsha 410008, China. gongh7411@hotmail.com
authors.forename: Hua
authors.initials: H
authors.lastname: Gong
authors.forename: Li-na
authors.initials: LN
authors.lastname: Zhang
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Cai
authors.forename: Yan-jin
authors.initials: YJ
authors.lastname: Wang
authors.forename: Yong-hong
authors.initials: YH
authors.lastname: Hou
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008170:Lung Compliance; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D001261:Pulmonary Atelectasis / Q000517:prevention & control*; D013990:Tidal Volume; D014057:Tomography, X-Ray Computed; D055815:Young Adult