EFFECT OF MAJOR SURGERY ON NEUTROPHIL CHEMOTAXIS AND ACTIN POLYMERIZATION IN NEONATES AND CHILDREN

The authors have examined the effect of major surgery in neonates and older children on neutrophil (PMN) chemotaxis and on actin polymerizat ion, an essential early step in PMN movement, Isolated PMNs from the f ollowing subjects were studied: healthy adult volunteers (n = 28), hea lthy newborns (0 = 21), newborns undergoing major surgery (0 = 7), and older infants and children undergoing major surgery (n = 14), Chemota xis was measured by a micropore filter assay, and actin polymerization was measured by flow cytometry. Blood samples from surgical patients were obtained preoperatively, hourly during the procedure, immediately postoperatively, and 48 hours after surgery. Mean preoperative newbor n PMN chemotaxis was similar to that of healthy newborn PMN, and mean preoperative PMN chemotaxis in children was similar to that of healthy adults, There were no significant alterations in PMN chemotaxis durin g or after major surgery in neonates or children. Peak PMN actin polym erization, after stimulation with formyl methionyl leucyl phenylalanin e (FMLP) (10 nm), was significantly diminished in healthy neonates com pared with adults (P <.005), Preoperative surgical neonates had simila r peak PMN actin polymerization levels to those of healthy newborns, a nd older preoperative children had similar levels to adults. PMN actin polymerization did not significantly change during or after major sur gery. Despite reductions in PMN chemotaxis and actin polymerization in healthy neonates, there is no further impairment of these PMN functio ns during or after major surgery, Our data suggest that PMN chemotacti c function is resistant to the stress of uncomplicated major surgery i n neonates and children. Copyright (C) 1997 by W.B. Saunders Company.