Paediatricsmiddle twist
A three-year-old girl weighing 14 kg is found with her grandmother's dose administration aid, which contains amitriptyline. Two hours later she is drowsy with 5 mm pupils, dry warm skin and a heart rate of 165 per minute; her first electrocardiogram shows a QRS of 110 milliseconds. She then has a two-minute generalised seizure and is intubated. Her blood pressure is now 68/40 mmHg and a repeat electrocardiogram shows a QRS of 150 milliseconds. Which one of the following is the most appropriate immediate treatment?