Effect of parenteral calcium treatment on blood pressure and heart rate in neonatal hypocalcemia.

Treatment of hypocalcemia in the normotensive but moderately ill neonate has been associated with an increase in blood pressure and heart rate. Blood pressure increased within five minutes after the end of a parenteral bolus infusion of calcium and remained elevated for approximately 50 minutes before returning to pretreatment values. Heart rate increased by 20 minutes after calcium infusion and the effect lasted through 90 minutes. Arterial and venous infusions of calcium were both followed by similar elevations in blood pressure and heart rate whereas infusions of saline were followed by no changes in either heart rate or blood pressure. The absence of other obvious explanations for the acute blood pressure elevation suggests that the increases in blood pressure and heart rate are directly related to or indirectly mediated by calcium therapy.