ALTERATIONS IN PLASMA PHOSPHORUS, RED-CELL 2,3-DIPHOSPHOGLYCERATE ANDP50 FOLLOWING OPEN-HEART-SURGERY

Objectives. To evaluate changes in and the correlation between plasma phosphorus, red cell 2,3-diphosphoglycerate (DPG) and adenosine tripho sphate (ATP), and P50 in children following heart surgery. Experimenta l design. Prospective, observational study with factorial design. Sett ing. A pediatric intensive care unit in a university hospital. Patient s. Twenty children undergoing open heart surgery for congenital heart defects. Interventions. None. Measures. Red cell 2,3-DPG and ATP, P50, plasma phosphorus, and arterial lactate were obtained before and at 1 , 8, 16, 24, 48, and 72 hours after surgery. The amount of intravenous fluid and glucose administered, and age of blood utilized were docume nted. Variables were analyzed by repeated measure analysis of variance followed by paired t-tests. To investigate the relationship between v ariables at each time point, scatter-plot matrices and correlation coe fficients were obtained. Results. There was a reduction in plasma phos phorus, red cell 2,3-DPG, and P50 and an increase in arterial lactate at 1, 8, 16, 24, 48, and 72 hours after surgery. Red cell 2,3-DPG corr elated with P50 at 1, 8 and 16 hours. The decrease in the plasma phosp horus correlated with the amounts of intravenous fluid and glucose adm inistered on the day of surgery and on the first and second postoperat ive days. The age of the blood utilized correlated with the decrease i n red cell 2,3-DPG on the day of surgery. Conclusions. Reduction in re d cell 2,3-DPG, P50, and plasma phosphorus occurs after open heart sur gery in children. These changes can potentially contribute to impaired oxygen utilization in the postoperative period, when adequacy of tiss ue oxygenation is critical.