Bronchiectasis in Acute Pneumonia ... Pseudobronchiectasis

normal and the oximetry was low. This suggests the dissociation curve was not shifted and the low oximetry seen in their patient was due to the fraction of the abnormal hemoglobin not binding oxygen. Secondly, the authors state that a rightward shift in the dissociation curve results in a higher p50. However, they incorrectly state that a rightward shift in the oxyhemoglobin dissociation curve occurs with blood transfusion, reduced levels of 2,3-diphosphoglycerate (DPG), hypophosphatemia, and hypothyroidism. Reduced levels of 2,3-DPG result in a leftward shift of the curve and increased affinity of oxygen binding to hemoglobin (lower p50).2 Reduced levels of 2,3-DPG are known to occur with hypothyroidism and hypophosphatemia.3 As well, stored blood has reduced levels of 2,3-DPG, potentially resulting in a leftward shift of the curve after transfusion.4