Figure 4From: Lung sonography and recruitment in patients with early acute respiratory distress syndrome: A pilot studyBoxplot of the arterial oxygen partial pressure at different PEEP levels (5, 10 and 15 cm H 2 O) in ARDS patients. {the upper and the lower boundary of the "box" (grey-shaded area) represents the 75th and 25th percentile of the data, the central black line of the " box" is the median value and the vertical lines indicate the maximum and the minimum values}Back to article page