Ubukata Y, et al. - Researchers performed this study on healthy volunteers [13 men and 2 women, mean age: 34 years (range 26–42)], to examine deviation of the bronchus by postural change from supine to lateral position during spontaneous respiration. The acquisition of chest radiograms (anterior–posterior) in the order of supine, left lateral, and right lateral position was followed by measuring bilateral bronchus angles and secondary carina angles in the acquired images. Thereafter, deviation of the bronchus in the lateral position was assessed by comparing the angles between the supine and lateral positions. A half of the male participants exhibited the curvature of left main bronchus (defined as more than 5° increase in secondary carina angle) during left lateral position. During one-lung ventilation, these anatomical changes due to the surgical posture could possibly account for ventilation failure and hence, should be kept in mind.