Nucleated red blood cells after cardiopulmonary bypass in infants and children: is there a relationship to the systemic inflammatory response syndrome?

In a retrospective case control study we aimed to evaluate whether infants and children with nucleated red blood cells (NRBCs) in their peripheral blood smears after cardiopulmonary bypass (CPB) had longer bypass times than controls without NRBCs. On review of a 3-year period, 58 children with NRBCs after CPB (and without NRBCs prior to CPB) were identified (cases). A random sample of 100 children without NRBCs after CPB over the same period served as controls. The median age (range) of the children with NRBCs and without NRBCs was 0.6 years (2 days to 20 years) and 1.4 years (2 days to 16 years), respectively ( p = 0.03). The children with NRBCs had a significantly longer bypass time than the controls (mean, standard deviation (SD): 114 min, 50 vs 79 min, 46 min; p < 0.0001). For the patients with postoperative polychromasia alone, the mean CPB time (111 min, SD 46 min) was also significantly longer than the respective time in the controls ( p < 0.001). Markers of organ dysfunction (renal failure, use of inotropic support, time of endotracheal intubation, stay in intensive care unit and stay in hospital) were significantly more frequent/longer in the NRBC group. Post-CPB release of NRBCs is associated with longer CPB time. This alteration may be part of the CPB-related systemic inflammatory response syndrome.