PERIOPERATIVE HEMODYNAMIC-EFFECTS OF AN INTRAVENOUS-INFUSION OF CALCIUM-CHLORIDE IN CHILDREN FOLLOWING CARDIAC-SURGERY

Twelve children received an infusion of 10% calcium chloride 0.1 ml/kg to a maximum dose of 5 ml, infused over 5 min, following open heart s urgery. Blood ionized calcium, systemic arterial pH, cardiac index, me an systemic arterial blood pressure and systemic vascular resistance i ndex were measured at baseline and repeated 20 and 40 min following co mpletion of the infusion. There was considerable overlap, with no sign ificant differences in the response to the calcium chloride infusion b etween children with ionized hypocalcaemia (< 1.1 mmol/l) and those wi th ionized normocalcaemia when its effect on percentage change in eith er the haemodynamic or biochemical measurements was assessed (p > 0.2 for all measurements; Mann-Whitney). For this reason they were treated as a single group. Significant changes from baseline were noted in me an systemic arterial pressure (p < 0.02), cardiac index (p < 0.01) and systemic vascular resistance index (p < 0.01) after completion of the calcium chloride infusion when analysed using Friedman's two-way anal ysis of variance. A significant increase in mean systemic arterial blo od pressure occurs after an infusion of 10% calcium chloride as a dire ct result of an increase in the systemic vascular resistance index wit h a concomitant decrease in cardiac index.