Erythrocyte 2,3-diphosphoglycerate depletion associated with hypophosphatemia detected by routine arterial blood gas analysis

OBJECTIVE: To describe a clinical case where an extremely low erythrocyte 2,3-diphosphoglycerate concentration (2,3-DPG) was discovered by routine blood gas analysis supplemented by computer calculation of derived quantities. The finding of a low 2,3-DPG revealed a severe hypophosphatemia. DESIGN: Open uncontrolled study of a patient case. SETTING: Intensive care observation during 41 days. PATIENT: A 44 year old woman with an abdominal abscess. INTERVENTIONS: Surgical drainage, antibiotics and parenteral nutrition. MEASUREMENTS AND RESULTS: daily routine blood gas analyses with computer calculation of the hemoglobin oxygen affinity and estimation of the 2,3-DPG. An abrupt decline of 2,3-DPG was observed late in the course coincident with a pronounced hypophosphatemia. The fall in 2,3-DPG was verified by enzymatic analysis. CONCLUSION: 2,3-DPG may be estimated by computer calculation of routine blood gas data. A low 2,3-DPG which may be associated with hypophosphatemia causes an unfavorable increase in hemoglobin oxygen affinity which reduces the oxygen release to the tissues.