title: Comparison of the PaO2/FiO2 ratio in sternotomy vs. thoracotomy in mitral valve repair:  a randomised controlled trial.
abstract: OBJECTIVE
  Cardiac surgery through a thoracotomy using one-lung ventilation (OLV) is thought to be associated with worse postoperative pulmonary gas exchange than sternotomy using two-lung ventilation (TLV), but this has not been confirmed yet. We, therefore, compared postoperative pulmonary gas exchange after mitral valve repair between sternotomy (group TLV) and thoracotomy (group OLV).
  
  
  METHODS
  Randomised controlled study.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  Cardiac surgery patients.
  
  
  METHODS
  Sternotomy or thoracotomy was used for mitral valve repair.
  
  
  METHODS
  The ratio of arterial partial pressure of oxygen (PaO2) to fraction of inspired oxygen (FiO2) was compared in both groups before induction of anaesthesia (T0) and just before departure from the operating room to the ICU (T1). Fluid administration, transfusion requirements and urine output were checked intraoperatively. Postoperative haemoglobin (Hb), haematocrit (Hct) and creatinine were evaluated. Cardiopulmonary bypass (CPB) time, intubation time and ICU stay were also recorded.
  
  
  RESULTS
  The PaO2/FiO2 ratio (mean ± SD) at T1 was significantly lower than at T0 in both groups (326.9 ± 120.1 vs. 431.9 ± 73.7 mmHg in group TLV, P < 0.001; 374.9 ± 130.9 vs. 445.4 ± 73.7 mmHg in group OLV, P = 0.001), but did not differ significantly between the two groups. The doses of inotropes and vaopressors used were not significantly different between the groups. Intraoperative fluid administration, transfusion requirements, urine output and postoperative Hb/Hct and creatinine did not differ significantly between the groups. CPB time, intubation time and ICU stay also did not differ significantly between the groups.
  
  
  CONCLUSIONS
  Perioperative pulmonary function following OLV via a thoracotomy was not significantly worse than that following TLV via a sternotomy in mitral valve repair.
  
  
  BACKGROUND
  Not registered.
authors: Department of Anaesthesiology and Pain medicine, Konkuk University Hospital and Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, South Korea.
authors: Woon-Seok
authors: WS
authors: Kang
authors: Tae-Gyoon
authors: TG
authors: Yoon
authors: Tae-Yop
authors: TY
authors: Kim
authors: Seong-Hyop
authors: SH
authors: Kim
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D016009:Chi-Square Distribution; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D010100:Oxygen / Q000097:blood*; D011182:Postoperative Care; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D056910:Republic of Korea; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D056346:Sternotomy / Q000009:adverse effects; D013908:Thoracotomy / Q000009:adverse effects; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010100:Oxygen