Culture Negative Sepsis after Pediatric Cardiac Surgery: Incidence and Outcomes

Background: A significant proportion of children after cardiac surgery with clinical features of blood stream sepsis do not have a positive blood culture and are managed as presumed ‘culture negative sepsis (CNS)’. There is little information on outcomes of CNS early after pediatric cardiac surgery. We sought to describe the incidence, outcomes and antibiotic utilization pattern of culture negative sepsis in children undergoing cardiac surgery. Methods: : 437 consecutive children who underwent cardiac surgery were studied. CNS was empirically defined as those in whom antibiotics were upgraded based on clinical and/or laboratory suspicion of blood stream sepsis with eventual negative blood culture. Outcomes were compared between three groups: normal controls, CNS and Culture Positive Sepsis (CPS). Results: : Incidence of CNS was 16% (71/437). The mortality was highest in CPS group (10.7%, 3/29); intermediate for CNS (2.9%, 2/71) and least for the normal group (1.2%, 4/337). Similarly, duration of ventilation and intensive care unit (ICU) length of stay (in hours) was highest for CPS (116 [45-271]; 288 [156-444]), intermediate for CNS (63 [23-112]; 192 [120-288]) and least for the normal group (18 [6-28]; 72 [48-120]). Third-tier antibiotics were initiated for 27 (40%) with CNS and 23 (92%) with CPS. Although the mean antibiotic duration for CNS (6.3±3.0 days) was less than CPS (9.09±5.12); p=0.022, 27.3% of CNS received antibiotics for more than one week. Conclusion: The high incidence of CNS points towards the need for accurate biomarkers of bacterial sepsis after cardiac surgery. The relatively better outcomes of CNS merits consideration to rapidly de-escalate antibiotics for presumed sepsis after cardiac surgery.