Absence of lung sliding is not a reliable sign of pneumothorax in patients with high positive end-expiratory pressure

The values of PEEP at which LS disappeared during the increasing arm of recruitment manouver did not show statistical significance from values obtained in the decreasing arm (Wilcoxon signed rank test, P=1.000 for the left lung, P=.875 for the right lung). [...]from data pooled for both sides and from both increasing and decreasing part of recruitment maneuver, the median value of PEEP at which LS disappeared as a false positive sign of pneumothorax was 25 cmH2O (interquartile range, 20-30 cmH2O) ( Fig. 2 ). [...]according to our study the median value of PEEP at which LS disappears as a false positive sign of pneumothorax is 25 cmH2O, LS was absent at PEEP 15 cmH2O in 4.5% and at PEEP 20 cmH2O in 26.9% of cases.