title: Arterial pCO2 changes during thoracoscopic surgery with CO2 insufflation and one lung ventilation.
abstract: BACKGROUND
  The respiratory effects (changes in pH and PaCO(2)) of carbon dioxide insufflation in thoracoscopic surgery in adult patients with pulmonary disease were not documented previously.
  
  
  METHODS
  In this observational study 21 patients scheduled for elective thoracoscopic surgery with one lung ventilation using a double lumen tube and intraoperative carbon dioxide insufflation were studied. Arterial blood gas findings were correlated with demographic and intraoperative variables.
  
  
  RESULTS
  When compared to baseline (10-15 minutes of one lung ventilation before carbon dioxide insufflation), carbon dioxide insufflation lowered the pH, 7.31±0.08 vs 7.40±0.05 (p<0.001) caused increased PaCO(2), 53±12 vs 42±6.0 (p<0.001) at 40-60 minutes after carbon dioxide insufflation. These derangements in arterial blood gases persisted in the post-anesthetic care unit with pH 7.33±0.04 vs 7.40±0.05 (p<0.001) and PaCO(2) 51±6.7 vs 42±6.0 (p<0.001). Moderate hypercarbia defined as PaCO(2) >50 mmHg, developed in 12 of 21 patients (57%) and was associated to lower FEV1/FVC ratios 60±21 vs 81±3%, older age 69±9 vs 56±17 years, and history of smoking, 43 ± 30 vs 16±21 pack years, p<0.05.
  
  
  CONCLUSIONS
  Intrathoracic carbon dioxide insufflation causes significant derangements in pH and PaCO(2) which is worse in patients with lower FEV1/FVC, increased age and smoking history.
authors: Department of Anesthesiology and Perioperative Medicine, Victoria Hospital, London Health Sciences Center.
authors: D T T
authors: DT
authors: Tran
authors: N H
authors: NH
authors: Badner
authors: G
authors: G
authors: Nicolaou
authors: W
authors: W
authors: Sischek
keywords: CO2 insufflation; one lung ventilation; thoracic surgery