This focused upon knowledge of aspects of respiratory physiology, measurement and oxygen delivery. Candidates were shown a chest X-ray, and told it represented complete collapse of the left lung. The opening question was what processes might contribute to hypoxia in that patient. It viva then went on to examine knowledge of shunt, dead space and measurement of oxygen. Overall most candidates performed well, with overall the depth of knowledge of the physiological mechanisms of hypoxia being the area of weakness.