Severe hypophosphatemia in a patient with diabetic ketoacidosis and acute respiratory failure

Although hypophosphatemia is a common complication during therapy of diabetic ketoacidosis, it is seldom severe and rarely causes clinical manifestations. We report a 39-year-old woman with diabetic ketoacidosis who developed acute respiratory failure after therapy. Although hyperglycemia and acidosis were corrected after treatment, respiratory distress and weakness still persisted. The chest radiograph showed no active lung lesion. Brain CT revealed no significant abnormality. Echocardiographic study revealed normal LV systolic wall motion. Blood biochemistry demonstrated severe hypophosphatemia of 0.3 mg/dL (normal value: 2.5 to 4.5 mg/dL). Phosphate replacement therapy with potassium phosphate was given. The patient's clinical condition improved steadily over the next few days, and after 4 weeks of hospitalization, she was discharged home without obvious long-term sequelae. In a critically ill patient, the symptoms of hypophosphatemia are not apparent and may mimic the symptoms of other underlying disease. Although phosphate replacement is not recommended routinely in diabetic ketoacidosis, if the patient develops cardiopulmonary distress, anemia or severe hypophosphatemia, phosphate therapy under close surveillance is indicated.