Aim To describe the incidence, patient profile, management strategies and outcome for infants and children who developed a chylothorax in the UK.

Methods A prospective study of infants and children ≥24 weeks’ gestation—≤16 years, who developed a chylothorax in the UK and were reported through the British Paediatric Surveillance Unit (BPSU). Clinicians completed a questionnaire on the presentation, diagnosis, management and outcome of these children. Three further data sources were accessed to confirm these data.

Results The incidence in children in the UK was 0.0014% (1.4 per 100 000) and 3.2% (3200 per 100 000) for those developing a chylothorax following a cardiac surgical procedure. The incidence was highest in infants ≤12 months at 16 per 100 000 (0.016%). A total of 219 questionnaires were returned with 172 cases meeting the eligibility criteria. Development of a chylothorax was most commonly associated with cardiac surgical procedure (65.1%) and was most frequently confirmed by laboratory verification of triglyceride content of the pleural fluid ≥1.1 mmol/L (66%). Although a variety of management strategies were employed, treatment with an intercostal pleural catheter (86.5%) and a medium chain triglyceride (MCT) diet (89%) was most commonly reported. The majority of the children had a prolonged hospital stay with a reported mortality of 12.2%.

Conclusions Development of a chylothorax in infants and children in the UK was not common. The primary association was with a cardiac surgical procedure. The child's hospital stay was lengthy and therefore the impact on the child, family and hospital resources were significant. Common management strategies existed but national guidance is required to optimise practice. This study allows for better information relating to this serious complication to be given to patients and families and provides the basis for future research and practice development.