title: The effects of cardiopulmonary bypass on pulmonary function during robotic cardiac surgery.
abstract: BACKGROUND
  We aimed to investigate the effects of cardiopulmonary bypass (CPB) on pulmonary function under the conditions of one-lung ventilation (OLV) and carbon dioxide pneumothorax in robotic cardiac surgery.
  
  
  METHODS
  Ninety-eight patients underwent robotic cardiac surgery using the da Vinci Surgical System, including 58 on-pump surgeries and 40 off-pump surgeries. Respiratory parameters and arterial blood gases were assessed at the following time points: 25 min after the induction of anesthesia under two-lung ventilation (T1), 25 min after OLV (T2), 25 min after the termination of CPB under OLV in the on-pump group or 25 min after the main surgery intervention in the off-pump group (T3) and 20 min before the end of surgery (T4). Dynamic lung compliance (Cdyn), alveolar-arterial PO2 difference (PA-aDO2), oxygenation index (OI) and artery-alveolar O2 pressure ratio (a/A) were calculated.
  
  
  RESULTS
  No significant differences in pulmonary function parameters between T2 and T3 were observed in the off-pump group. However, in the on-pump group, compared with those at T2, PETCO2, Ppeak, PaCO2 and PA-aDO2 at T3 were higher, whereas SpO2, Cdyn, PaO2, OI and a/A were lower (p<0.05). Comparisons between the two groups at T3 indicated that SpO2, Cdyn, PaO2, OI and a/A were higher, while Ppeak, PaCO2 and PA-aDO2 were lower in the off-pump group (p<0.01).
  
  
  CONCLUSIONS
  In robotic cardiac surgery under the conditions of OLV and carbon dioxide pneumothorax, CPB worsened pulmonary function and tolerance to OLV and carbon dioxide pneumothorax.
authors.affiliation: PLA Institute of Cardiac Surgery, PLA General Hospital, Beijing, China.
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.affiliation: PLA Institute of Cardiac Surgery, PLA General Hospital, Beijing, China.
authors.forename: S
authors.initials: S
authors.lastname: Xiao
authors.affiliation: PLA Institute of Cardiac Surgery, PLA General Hospital, Beijing, China anesth301@aliyun.com.
authors.forename: C
authors.initials: C
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000379:methods*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D061810:One-Lung Ventilation / Q000379:methods*; D011031:Pneumothorax, Artificial / Q000379:methods*; D012129:Respiratory Function Tests; D065287:Robotic Surgical Procedures / Q000379:methods*
keywords: anesthesia; cardiopulmonary bypass; one-lung ventilation; pulmonary function; robotic cardiac surgery