MONITORING IONIZED CALCIUM ALLOWS DECREASED THERAPY FOR EARLY HYPOCALCEMIA IN VERY LOW BIRTH WEIGHT (VLBW) INFANTS. 1255

Universal calcium (Ca) therapy in the first days of life for VLBW infants with a total serum Ca < 7.0 mg/dl may pose unnecessary risks. Total serum Ca may not adequately reflect Ca status. We evaluated the use of ionized Ca obtained with blood gas measurements in a clinical setting to determine if we could decrease the number of infants treated for hypocalcemia. Forty infants< 1500 grams birthweight requiring mechanical ventilation were enrolled in the study. Both ionized Ca and total serum Ca were simultaneously measured at 12, 24, 36, and 48 hours of age. A Smooth E syringe from Radiometer was used to collect 0.3 ml of blood for an ABG and ionized Ca and values measured on a Radiometer ABL 505 Analyzer. The total serum Ca was measured on a Kodax EKTACHEM 700 Chemistry Analyzer. An EKG was obtained at 24 hours of life to evaluate changes associated with hypocalcemia. Infants were also assessed for any clinical symptoms of hypocalcemia. If the ionized Ca was < 0.80 mmol/l, therapy for hypocalcemia was instituted.