Prolonged granulocyte activation, as well as hypoxanthine and free radical production after open heart surgery in children.

OBJECTIVE

To investigate granulocyte activation, as well as hypoxanthine and free radical production in children during the first day after cardiopulmonary bypass.

DESIGN

A prospective study of pediatric patients undergoing either cardiac surgery with a cardiopulmonary bypass or thoracotomy and extracardiac vascular surgery not requiring a cardiopulmonary bypass.

SETTING

Operative and intensive care units, Children's Hospital, University of Helsinki, Finland.

PATIENTS: Seven consecutive patients undergoing elective correction of a ventricular septal defect and six patients undergoing extracardiac surgery for ligation of a patent ductus arteriosus or repair a coarctation of the aorta.

MEASUREMENTS AND MAIN

RESULTS

Plasma concentrations of myeloperoxidase (140-334 micrograms/l preoperatively, 460-1692 micrograms/l at 0.2 h after declamping, 471-1386 micrograms/l at 0.5 h after declamping) and lactoferrin (77-258 micrograms/l preoperatively, 533-1783 at 0.2 h, 404-1482 micrograms/l at 0.5 h) as markers of granulocyte activation, and hypoxanthine (0-5.7 mumol/l preoperatively, 4.3-17.0 mumol/l at 0.2 h, 6.5-17.9 mumol/l at 0.5 h) increased in a biphasic manner at 0.2-0.5 h and 6-10 h postoperatively (all p < 0.05). Expired ethane, as an index of free radical activity, increased at 10 h postoperatively (36-119 pmol/kg per min preoperatively, 72-152 pmol/kg per min, p < 0.005).

CONCLUSION

Granulocyte activation, and hypoxanthine and free radical production occur at least 10 h after cardiopulmonary bypass. In children undergoing open heart surgery, attempts to reduce free radical activity should be extended to the postoperative period.