AbstractBackground: Respiratory infections are considered a potential risk of adverse events in children undergoingsurgery. Rhinovirus is a common cause of respiratory infections and congenital... Show moreAbstractBackground: Respiratory infections are considered a potential risk of adverse events in children undergoingsurgery. Rhinovirus is a common cause of respiratory infections and congenital heart disease is a risk factor forsevere rhinovirus infection. However, we do not know what the impact of, clinical or subclinical, rhinovirus infectionsis on postoperative course following congenital heart surgery in children.Based on our clinical experience, one case-controlled study, and a case reported in the literature, we hypothesizethat paediatric patients with per-operative rhinovirus positive Polymerase Chain Reaction testing have a longerpaediatric intensive care unit admission, compared to children who test negative.Methods/Design: This is a prospective single-center observational study in the Leiden University Medical Centerwith approximately 250 children (<12 years) undergoing elective cardiac surgery, for congenital heart disease.The parents/guardians of the children will be asked to fill out a questionnaire, to asses respiratory symptoms inthe last weeks, before the operation of their child. In the operating theatre, a nasopharyngeal swab will be collected.Clinical data will be collected daily during paediatric intensive care admission and paediatric intensive care unit andhospital length of stay will be recorded. If children are still intubated at day 4, a second nasopharyngeal swab andresidual blood will be collected. The samples will be tested for rhinovirus with polymerase chain reaction. Primaryoutcome is the paediatric intensive care unit length of stay in per-operative rhinovirus-positive compared torhinovirus-negative patients.Discussion: This is the first study to screen children for rhinovirus before undergoing cardiac surgery and tostudy the effects on paediatric intensive care unit length of stay. Furthermore, we aim to identify children at risk forprolonged paediatric intensive care admission after cardiac surgery. Show less