Dr Henry Jefferson, Consultant Anaesthetist
#QuestionFeedback 14. Apical V/Q Is the V/Q ratio infinite at the apex of the lung? Not normally. Although apical perfusion is relatively low, it is not absent in a healthy upright adult. An infinite V/Q ratio requires ventilation with ZERO perfusion, representing alveolar dead space. Conversely, V/Q = 0 represents perfusion without ventilation (shunt). The normal lung apex has a HIGH V/Q ratio, but not an infinite one.