Increased alveolar O2 concentration is due to which of the following condition?: (A) Intra cardiac right to left shunt, (B) Asthma, (C) Pulmonary hemorrhage, (D) Ventilation perfusion mismatch
Answer is D. A high V/Q ratio increases paO2 and decreases paCO2. This finding is typically associated with pulmonary embolism (where blood circulation is impaired by an embolus). A high V/Q can also be observed in COPD as a maladaptive ventilatory overwork of the undamaged lung parenchyma. In Asthma and Pulmonary hemorrhage there is decreased O2 concentration.