Exchange transfusion for hyperleucocytosis in a critical case of pertussis.

An 8-week-old infant girl with pertussis-induced respiratory distress, complicated by severe leucocytosis, pulmonary hypertension and respiratory failure is reported. She was treated with mechanical ventilation, exchange transfusion and other supportive measures. A single-volume exchange transfusion significantly reduced the elevated white blood cell count and stabilised her condition. This case underscores the potential role of exchange transfusion as a life-saving intervention in critical pertussis cases with severe leucocytosis.