This is a prospective single- center observational study in the Leiden University Medical Center in 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 in the last weeks, before the operation of their child. In the operating theatre, a nasopharyngeal swab will collected. Clinical data will be collected daily during paediatric intensive care admission, and date of discharge from paediatric intensive care unit and from hospital are recorded. If children are still intubated at day 4 a second nasopharyngeal swab and residual blood will be collected. The samples will be tested for rhinovirus with a polymerase chain reaction. Main study parameter is the paediatric intensive care unit length of stay in per-operative rhinovirus -positive compared to rhinovirus-negative patients.

Rationale:

Respiratory infections are considered to carry a potential risk of adverse events in children undergoing surgery.

Rhinovirus is a common cause of respiratory infections and congenital heart disease is a risk factor for severe rhinovirus infection. However, we do not know what the impact of clinical or subclinical rhinovirus infections is 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 hypothesize that paediatric patients with per-operative rhinovirus positive Polymerase Chain Reaction (PCR) testing have a longer paediatric intensive care unit (PICU) admission , compared to children who test negative.

Objectives:

Primary: To identify whether PCR-proven rhinovirus is a risk factor for prolonged PICU admission in children undergoing cardiac surgery.

Secondary: to develop a preoperative algorithm to identify children with increased risk for prolonged PICU admission after cardiac surgery.

Study design:

This is a prospective single-center observational cohort study in the Leiden University Medical Center (LUMC).

Methods Parents of the selected patients will receive the information folder and a questionnaire by mail (asking for signs and symptoms of current and/or recent respiratory infections) when they receive the letter with the date of admission and operation.

On the day of admission (day -1) all (parents of) children admitted for cardiac surgery will be asked to participate in this study and fill out a written informed consent.

At day 0, the operation day, in the operating theatre a nasopharyngeal swab will be collected following anaesthetic induction and tested for rhinovirus. All clinicians will be blinded for the PCR results and will only be made known to the investigator from the virology department.

Clinical and laboratory data will be collected for all patients until discharge from the hospital. Of all the patients still on mechanical ventilation at day 4, an additional nasopharyngeal swab will be sampled and scavenge samples blood will be requested at the chemical laboratory if available. Rhinovirus PCR will be performed on nasopharyngeal swab and blood to determine shedding and viremia.

Residual blood (for infection parameters) will be collected at three time points: after induction of anaesthesia, directly after operation at PICU admission and at day four (4) when the patient is still on ventilator support.

Inclusion Criteria:

• Children (<12 year) with a congenital heart disease undergoing elective cardiac surgery
• Written informed consent by parents or guardian

Exclusion Criteria:

• No informed consent from one of the parents (or the legal representative if applicable)
• Anaesthesiologist or cardiopulmonary surgeon postpones surgery based on routine hospital screening
• Emergency surgery
• Pre-operative admission to the neonatology department
• Children not admitted to the intensive care unit after cardiac surgery
• Children undergoing a second cardiac operation during the same intensive care stay
• Children with duct-dependent physiology who remain prostaglandin-dependent after the heart operation (they will be excluded because they will certainly have a prolonged PICU LOS regardless of a possible rhinovirus infection). For example: hypoplastic left heart syndrome following pulmonary artery banding who will remain on prostaglandins until the next staged operation

Children (<12 year) with a congenital heart disease undergoing elective cardiac surgery