A prospective audit of paediatric cardiac MRI under general anaesthesia; practise and problems

Abstract

Background: Cardiac MRI (CMRI) is increasingly used to augment surgical planning and follow up of children with congenital heart disease. General anaesthesia (GA) is always required for imaging small children. We describe our experience of GA for paediatric CMRI, using data collected prospectively over 3 years. Methods and Results: 120 patients presented for CMRI under GA from November 2005 to May 2008. Patients were aged 0-288 months (median 28 months), and weighed 2.8-64kg (median 11.7 kg). Fifty-seven children (47.5%) had a functionally single ventricle. Fifty patients (42%) had normal oxygen saturations. Of the cyanosed patients, pulmonary blood flow was supplied through an aorto-pulmonary shunt in 33% and 13% had a cavopulmonary shunt. Sixteen patients (13%) had a mixed circulation. Six patients (5%) had severely impaired systemic ventricular function. 14 patients (11.6%) had at least moderate systemic outflow tract obstruction. The majority of patients (90%) were admitted as a day-case for CMRI. A senior, cardiac anaesthetist was continuously present during every case. Most patients (100/120, 83%) received inhalational inductions with sevoflurane. The majority of children (85/120, 71%) had an uneventful CMRI under GA. Thirtythree (27.5%) patients suffered minor adverse events. One major adverse event occurred; a patient with hypoplastic left heart syndrome (HLHS) became hypotensive and underwent successful resuscitation in the MRI scanner. Conclusions: Despite the precarious physiology of children with congenital heart disease, GA for CMRI can be administered safely, with a senior multi disciplinary team. Inter-stage HLHS patients are at particularly risk of serious morbidity.