Patients were randomly divided into two groups: ultrasound-guided (US-guided) out-of-plane internal jugular vein (OOP-IJV) and in-plane supraclavicular subclavian vein (IP-SSV) catheterization.

For OOP-IJV cannulation, the transducer was placed to identify IJV in short-axis view. The needle was introduced at an angle of 60° to the skin surface, and advanced under real-time US guidance until visualizing the tip of the needle inside the vein.

For IP-SSV cannulation, a short-axis view of the IJV was obtained first. The probe was slid caudally following the IJV until getting the best long-axis view of the SCV. Using an in-plane approach, the needle was inserted at the base of the transducer at a 30° angle and advanced under the long axis under real-time US guidance targeting the SCV.

Patients were randomly divided into two groups: ultrasound-guided (US-guided) out-of-plane internal jugular vein (OOP-IJV) and in-plane supraclavicular subclavian vein (IP-SSV) catheterization.

For OOP-IJV cannulation, the transducer was placed on transverse position over the patient's neck at the level of the cricoid cartilage to identify IJV and carotid artery (CA) in short-axis view. The vein was then centered on the screen. The skin puncture was made in the center of the US image using a needle attached to a syringe. The needle was introduced at an angle of 60° to the skin surface, perpendicular to the transducer, and advanced under real-time US guidance toward the IJV until visualizing the tip of the needle inside the vein.

For IP-SSV cannulation, a short-axis view of the IJV was obtained first. The probe was slid caudally following the IJV until the junction of the subclavian vein (SCV) and IJV was reached in the supraclavicular fossa. The probe was then turned slightly and tilted anteriorly to get the best long-axis view of the SCV and the brachiocephalic vein (BCV).

Using an in-plane approach, the needle attached to a syringe was inserted at the base of the transducer at a 30° angle and advanced strictly under the long axis of the US probe from lateral to medial. The needle point was then guided under real-time US guidance targeting the SCV.

In both groups, catheterization was done through Seldinger technique.

Inclusion Criteria:

• Patients admitted in intensive care unit requiring a central venous catheter (CVC)

Exclusion Criteria:

• Major blood coagulation disorders,
• Any thrombotic formations within the vein,
• Congenital or acquired deformity of neck or clavicle
• Cannulation site infection, hematoma and surgery.