This study aims to define a simple, safe, and effective ultrasound pre-scan technique for right internal jugular vein (RIJV) cannulation. After placing the patient properly, the operator puts a linear ultrasound probe at the mid neck in short-axis view. With the IVJ in the center of the screen, the operator makes marks at both ends of the transducer (mark A and B), and then rotates the transducer 90 degrees counterclockwise. After finding IJV in long-axis view with transducer vertical to the ground, other two marks are made at both ends of the transducer (mark C and D). After proper preparation, the operator recognizes the cross point made by the imagined lines of marks AB and marks CD (point E). The needle is inserted vertically to the ground at point E.

Inclusion criteria are adult patients receiving general anesthesia in need of central venous cannulation.The primary endpoint is the number of needle redirection, and secondary endpoints include first attempt success rate, artery puncture, complication, number of wire attempt, number of skin insertion, venous access time, catheterization time, and malposition. The hypothesis is that this ultrasound pre-scan method would have a fewer number of needle redirection, a higher first-attempt success rate, as well as less complication, number of redirection.

Ultrasound-guided central venous cannulation has been widely used because of lower technical failure rate and complications, and faster access compared with landmark-guided cannulation. Real-time guidance is more complex to perform and time-consuming in comparison to pre-scan technique. Therefore, real-time guidance should be reserved to specific groups, such as infants, children, or those with anatomical abnormality. However, there's no widely accepted ultrasound pre-scan techniques yet. The aim of this study is to define a simple, safe, and effective ultrasound pre-scan technique for right internal jugular vein (RIJV) cannulation.

Patient position for RIJV cannulation was reviewed in detail. First, 15ﾟ Trendelenburg tilt significantly increases the diameter of right internal jugular vein. Second, extreme head rotation to the opposite side will increase the overlap percentage between IJV and common carotid artery (CCA), but neutral head position might make the procedure difficult. Neutral head position or small degree (≦15ﾟ) of head rotation was recommended. Third, although shoulder roll is not recommended since it decreases the anterior-posterior diameter of RIJV, 4- to 5cm-high shoulder roll could be used to reduce the overlap if needed10. In conclusion, patients should be positioned by a 15ﾟ Trendelenburg tilt and 15ﾟ head rotation to the opposite side without a shoulder roll unless the IJV is anterior to CCA, which was termed as the rule of 15 by the research team.

After placing the patient properly, the operator puts a linear ultrasound probe at the mid neck in short-axis view. With IVJ in the center of the screen, marks at both ends of the transducer (mark A and B) are made. Then the operator rotates transducer 90 degrees counterclockwise. After finding IJV in long-axis view with transducer vertical to the ground, other two marks are made at both ends of the transducer (mark C and D), and transducer and jelly are removed. Then the operator sterilizes the performing field with chlorhexidine without removing the marks. After proper preparation and recognizing the cross point made by the imagined lines of marks AB and marks CD (point E), the operator inserts the needle vertically to the ground at point E.

The aim of this study is to compare the effectiveness and safety between ultrasound pre-scan technique and traditional landmark-guidance. Inclusion criteria are adult patients receiving general anesthesia in need of central venous cannulation. The primary endpoint is the number of needle redirection, and secondary endpoints include first attempt success rate, artery puncture, complication, number of wire attempt, number of skin insertion, venous access time, catheterization time, and malposition. The hypothesis is that the ultrasound pre-scan method would have a fewer number of needle redirection, a higher first-attempt success rate, as well as less complication, number of redirection.

Inclusion Criteria:

• Older than 20 years and younger than 80 years of age
• American Society of Anesthesiologists Physical Status Classification I-III (no immediate life-threatening condition)
• Scheduled for regular surgery
• Receive general anesthesia with endotracheal tube intubation
• In need of central venous catheter placement

Exclusion Criteria:

• Body Mass Index > 35kg/m^2
• Abnormal anatomy of the neck
• Limited range of motion of the neck
• The surgery does not allow right internal jugular vein cannulation or other contraindications for the procedure

There's no plan of sharing individual participant data currently