Arnold P, Sanaulla S, Hampson LV, et al. - Given that magnetic resonance (MRI) scanning of the heart is an established part of the investigation of cardiovascular conditions in children, researchers sought to determine the dose of remifentanil required by infusion to suppress ventilation sufficiently to allow a 30-second apnea during MRI imaging of the heart. Patients aged 1 to 6 years were exposed to different doses of remifentanil and success in achieving 30 seconds of apnea was noted. Using logistic regression, a final estimate of the dose needed to achieve a successful outcome in 80% of patients (ED80) was calculated. Thirty-eight patients were recruited and apnea was achieved in 31 patients. Data reported that the estimate of the ED80 was 0.184 µg/kg/min (95% CI 0.178‐0.190). This differs from the ideal dosing determined for other indications, and remifentanil dosing should be tailored to the clinical situation.