MCSL and OA-IP for IJV catheterization.
MCSL, volume, bowel preparation
All catheterization were performed from the skull to the caudal in the neck region. (a)(b)(c) MCSL approach. (d) OA-IP approach. (a) Step 1: Determine the puncture plane. (b) Step 2: Short-axis out-of-plane puncture. (c) Step 3: Long axis in-plane puncture. (d) Lateral Oblique-axis in-plane puncture. MCSL, Modified combined short and long axis method; OA-IP, Oblique axis in-plane method; IJV, internal jugular vein; CCA, common carotid artery; (red arrows), Ultrasound shadows; (white arrows), Needle.Before skin preparation, pre-ultrasonography was performed to verify patency of the right IJV and its sonoanatomy parameters (the diameter of IJV, the area of IJV (trace method), depth of IJV and the overlap between IJV and CCA under the short axis view) were measured. The following clinical variables were also recorded: age, sex, height, weight, neck length (from clavicle to mandibular border), fasting time, preoperative infusion volume, bowel preparation situation and the type of catheter (single (5 French) or double lumen (7 French) catheters).