Radial Artery Dimensions and the Effect of Anaesthetic Induction in Morbid Obesity

This single-centre prospective study measured the internal diameter of the radial artery and the distance between the skin surface and the arterial lumen by ultrasound in 76 adults with a body mass index of 40 kg/m2 or above who were scheduled for elective surgery under general anaesthesia. Measurements were made 2 cm proximal to the radial styloid process before induction of anaesthesia and again 5 minutes after endotracheal intubation, so that each patient served as their own control. The relationship of these measurements with anthropometric variables was examined. Patients were additionally randomized to radial artery cannulation with either an 18 G or a 20 G cannula, and the two cannula gauges were compared with respect to the time to successful cannulation and the number of skin punctures.