Biological impact of manual blood exchange in malignant Bordetella pertussis infection in infants

Abstract

Background and objectives: Manual blood exchange (MBE) is a leukoreduction therapy for hyperleukocytosis in Bordetella spp.

Infection: We describe the impact of BE on clinical and biological parameters in critically ill children with malignant pertussis.

Materials and methods: This is a monocentric retrospective review of patients with malignant pertussis infection treated with MBE. It describes the evolution of haemodynamic, ventilatory, haematologic and metabolic characteristics before and after MBE.

Results: Between January 2006 and December 2021, nine patients (median age 43 days, range: 13-80 days) had 16 MBE for malignant pertussis. All patients were mechanically ventilated, and 7/9 patients developed pulmonary hypertension during their paediatric intensive care unit (PICU) stay. Overall, 3/9 patients survived, and the mean PICU length of stay was 8.5 days (range: 1-52 days). We found a significant reduction of the leukocyte count (pre-MBE: 61.8 G/L [interquartile range (IQR): 55.8-74.8] vs. post-MBE: 19.4 G/L [IQR: 17.7-24.1]; p ≤ 0.001) and significant oxygenation improvement (pre-MBE SpO₂/FiO₂: 190 [IQR: 106-200] vs. post-MBE SpO₂/FiO₂: 242 [IQR: 149-250]; p = 0.03). The main side effects were a significant reduction of thrombocytes (pre-MBE: 411 G/L [IQR: 166.5-563.5] vs. post-MBE: 66 G/L [IQR: 46-82.5]; p = <0.001) and of ionized calcium (iCa) (pre-MBE iCa: 1.3 [IQR: 1.22-1.37] vs. post-MBE iCa: 1.25 [IQR: 1.85-2.24]; p = 0.03).

Conclusion: MBE efficiently reduces leukocytes and improves oxygenation in severe Bordetella pertussis infection in infants. Careful monitoring of calcium and thrombocytes seems mandatory.

Keywords: Bordetella pertussis; PICU; blood exchange; hyperleukocytosis.