Risk factors and mortality in children with severe pertussis: the role of exchange transfusion in a PICU.

Objective: Although multiple risk factors have been reported for adverse outcomes in children with severe pertussis, their predictive values and the benefits of interventions such as exchange transfusion remain poorly understood. Therefore, we aimed to comprehensively evaluate the risk factors associated with mortality in children with severe pertussis and assess the potential benefits of exchange transfusion therapy.

Methods: A retrospective analysis of 170 pertussis patients admitted to the Pediatric Intensive Care Unit (PICU) between January 2018 and June 2024 was performed.

Results: Among the 170 patients, 38 (22.35%) died. The death group exhibited significantly higher white blood cell (WBC) counts (67.31 vs. 28.41 × 10^9/L, P < 0.001), neutrophils (29.95 vs. 11.61 × 10^9/L, P < 0.001), and C-reactive protein (CRP) (29 vs. 8 mg/L, P < 0.001). Additionally, sepsis (39.47% vs. 9.09%, P < 0.001), shock (63.16% vs. 6.06%, P < 0.001), ARDS (23.68% vs. 2.27%, P < 0.001), and acute kidney injury (21.05% vs. 0.76%, P < 0.001) were more prevalent in the death group. ROC analysis showed that WBC counts had a predictive value for mortality (AUC = 0.75, sensitivity = 0.78, specificity = 0.68), with an optimal cutoff of 48.58 × 10^9/L.

Conclusions: High WBC counts are significantly correlated with increased mortality risk in severe pertussis children, with a threshold of 48.58 × 10^9/L marking high risk. Although exchange transfusion can reduce WBC counts and improve symptoms, its benefit is limited in patients with severe secondary infections, necessitating tailored treatment strategies.