Background Malignant pertussis (MP) affects young infants and is characterised by respiratory distress, associated with permanent tachycardia and hyperleukocytosis up to 50 × 109L-1 leading to multiple organ failure and death in 75% of cases. Leukodepletion aims to improve prognosis.
Method This study aimed at identifying factors associated with death and evaluating the impact of treatment on the outcome. We reviewed the records of the infants ≤3 months, hospitalised in 7 French paediatric intensive care units (PICUs) from January 1, 2008 to November 13, 2013with a diagnosis of pertussis, admitted for respiratory distress, with or without white blood cell count (WBCC) >50 × 109L-1. Treatment modalities (Leukodepletion and/or ECMO) were compared to Rowland’s proposition (Rowlands et al, paediatrics 2010).
Results Twenty three infants were included, 17 were intubated. Nine of 23 (40%) died: they presented more frequently cardiovascular failure (100% vs 36%, p = 0.003) and pulmonary hypertension (PHT) (100% vs 29%, p = 0.002) than survivors. Fatal cases presented CRP level at emergency >20 mg/l (85% vs 14%, p = 0,003) and increased their WBCC three times faster than survivors (15 × 109L-1pd vs 5 × 109L-1pd, p = 0,013). Leukodepletion was performed in 10 cases (43%), 7 survived. For 15/23 patients, the treatment followed Rowlandsprotocol, resulting in a 73% survival rate (11/15).
Conclusion A CRP level over 20 mg/l at hospital admission and an increase of WBCC >15×109L-1pd were associated with death. Early determination of CRP, early monitoring of WBCC every 12h, and determination of PHT by echo should be helpful in predicting the prognosis of MP and initiating Leukodepletion.