Comparison of two protective lung ventilatory regimes on oxygenation during one-lung ventilation: a randomized controlled trial.
BACKGROUND
The efficacy of protective ventilation in acute lung injury has validated its use in the operating room for patients undergoing thoracic surgery with one-lung ventilation (OLV). The purpose of this study was to investigate the effects of two different modes of ventilation using low tidal volumes: pressure controlled ventilation (PCV) vs. volume controlled ventilation (VCV) on oxygenation and airway pressures during OLV.


METHODS
We studied 41 patients scheduled for thoracoscopy surgery. After initial two-lung ventilation with VCV patients were randomly assigned to one of two groups. In one group OLV was started with VCV (tidal volume 6 mL/kg, PEEP 5) and after 30 minutes ventilation was switched to PCV (inspiratory pressure to provide a tidal volume of 6 mL/kg, PEEP 5) for the same time period. In the second group, ventilation modes were performed in reverse order. Airway pressures and blood gases were obtained at the end of each ventilatory mode.


RESULTS
PaO2, PaCO2 and alveolar-arterial oxygen difference did not differ between PCV and VCV. Peak airway pressure was significantly lower in PCV compared with VCV (19.9 ± 3.8 cmH2O vs 23.1 ± 4.3 cmH2O; p < 0.001) without any significant differences in mean and plateau pressures.


CONCLUSIONS
In patients with good preoperative pulmonary function undergoing thoracoscopy surgery, the use of a protective lung ventilation strategy with VCV or PCV does not affect the oxygenation. PCV was associated with lower peak airway pressures.
Department of Anesthesiology, Fundación CardioInfantil-Instituto de Cardiología, Calle 163 A # 13B-60, Bogotá, Colombia, South América. felixmontes@etb.net.co
Félix R
FR
Montes
Daniel F
DF
Pardo
Hernán
H
Charrís
Luis J
LJ
Tellez
Juan C
JC
Garzón
Camilo
C
Osorio
D000293:Adolescent; D000328:Adult; D000368:Aged; D000758:Anesthesia; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D011175:Positive-Pressure Respiration; D012121:Respiration, Artificial / Q000379:methods*; D013906:Thoracoscopy; D013990:Tidal Volume; D055815:Young Adult
D002245:Carbon Dioxide; D010100:Oxygen