RESUMEN
BACKGROUND: Major surgery suppresses the cell-mediated immune response in children and adults. Data on preoperative and postoperative T-cell counts in pediatric surgical patients and their relationship to health-care-associated infection (HAI) are not yet known. METHODS: A prospective observational study was carried out in a level III multidisciplinary neonatal and pediatric intensive care unit. Before and after, and in the first 3 days after surgery, lymphocyte subsets in peripheral blood were measured in 28 neonates and infants on flow cytometry. HAI were classified according to CDC/NHSN criteria. RESULTS: Six out of 28 neonates and infants (21.4%) developed HAI (group I-HAI), while 22 out of 28 (78.6%) remained infection free (group II-non-HAI). In group I with HAI, the preoperative median cytotoxic T-lymphocyte (CD8-T-cell) level was found to be below normal, and remained very low throughout the study period. In addition, the median and interquartile CD8 T-cell range (358 cells/µL; 304-424 cells/µL) were twice as low compared to group II without HAI (822 cells/µL; 522-933 cells/µL; P = 0.013). No differences were found between the two groups with regard to patient demographics and clinical data. CONCLUSION: Neonates and infants who underwent a major surgical procedure and who had a very low preoperative CD8 T-cell level, developed HAI postoperatively.