Background
One lung ventilation (OLV) is accomplished with a double lumen tube (DLT) or a bronchial blocker (BB). In this study, we compared the effectiveness of lung collapse using DLT, BB with spontaneous collapse, and BB with disconnection technique.
Methods
Fifty-two patients undergoing elective pneumothorax surgery were included in this study. The patients were randomly assigned to one of three groups: DLT with spontaneous collapse group (Group 1), BB with spontaneous collapse group (Group 2), and BB with disconnection technique group (Group 3). In Group 3, we modified disconnection technique; 1) turned-off the ventilator and opened the adjustable pressure limiting valve allowing both lungs to collapse, 2) after loss of CO2 trace in the capnograph, 3) inflated blocker cuff and turned-on the ventilator allowing only dependent-lung reventilation. Five and ten min after OLV, lung collapse degree was assessed by the surgeon, who was blinded to the isolation technique.
Results
The overall degrees of lung collapse were different among groups (p = 0.001 at 5 min, p = 0.002 at 10 min). In the paired intergroup comparisons, the qualities of lung collapse degree at 5 min and 10 min were better in the Group 1 and in the Group 3 than in the Group 2 significantly. There were no differences between Group 1 and Group 3 in lung collapse degrees at any time points. In Group 3, the average time for loss of CO2 trace in the capnograph was 32.3 ± 7.0 sec.
Conclusions
BB with spontaneous collapse takes longer to deflate and do not provide equivalent surgical exposure to DLT. To accelerate the collapse of the lung in BB, disconnection technique could be helpful and the disconnection time required is about 30 sec.
