Plasma neuropeptide Y and catecholamines in pediatric patients undergoing cardiac operations.

OBJECTIVE

Our objective was to assess the sympathoadrenal response in pediatric patients undergoing repair of congenital cardiac defects.

METHODS

Plasma catecholamine (norepinephrine and epinephrine) and neuropeptide Y concentrations were quantified before and after cardiopulmonary bypass to assess the response to cardiopulmonary bypass. To determine the response to aortic occlusion, levels of plasma catecholamines and neuropeptide Y were measured at the time of and immediately after release of the aortic crossclamp.

RESULTS

During cardiopulmonary bypass, no significant change in levels of plasma norepinephrine (n = 43), epinephrine (n = 37), or neuropeptide Y (n = 46) was observed. Aortic occlusion induced a significant increase in plasma neuropeptide Y, but not in catecholamines. There was a greater increase in plasma neuropeptide Y in children older than age 1 year than in those younger than 1 year.

CONCLUSIONS

Plasma neuropeptide Y may be a useful marker of sympathetic nervous system activity. Children younger than age 1 year showed a lesser sympathetic response compared with the response in older children.