Hypocalcemic Hypotension

To the Editor.— The report of Chaimovitz et al (222:86-87, 1972) shows good differential diagnosis can be made by utilizing clinical and electrocardiographic signs of hypocalcemia despite the lack of adequate laboratory methods to measure ionized calcium. During massive blood transfusion with citrated blood in both infants and in adults in the past decade, I have frequently used calcium salts, gluconate, or chloride to restore normal blood pressure. Usually the electrocardiographic changes were the only indication of hypocalcemia, while total serum calcium determinations gave little or no help in diagnosis. The prompt return of blood pressure to normal, reduction in heart rate, reversion of electrocardiographic abnormalities, and reduction in PEP/LVET (an index of cardiac contractility that I have utilized in the past decade) in combination indicated increased cardiac contractility following calcium administration. In order to prevent cardiac depression and arrhythmia or arrest during massive blood transfusion, especially to counteract the