Abstract
It is well known that hypophosphatemia often occurs during insulin therapy of diabetic ketoacidosis. However, tha necessity and efficacy of phosphate replacement is still controversial. We encountered a fresh case of IDDM in which acute respiratory failure and myocardial dysfunction with severe hypophosphatemia developed in the course of insulin therapy of ketoacidosis. Intravenous administration of phoshate rapidly improved the respiratory and cardiac condition, suggesting the importance of phosphate supply. Monitoring and adequate replacement of phosphate appears to be necessary, especially in patients with severe acidosis.