Internal jugular, subclavian, or femoral veins are often used for central venous catheter (CVC) placement. Regardless of which vein is preferred, the "Seldinger" technique is used most frequently. The most commonly used method with ultrasound is the short-axis out-of-plane approach. The main problem in this method is that the correct needle tip is missed, and it causes some complications by causing posterior wall punctures. The "Syringe-free" technique is first reported by Matias et al. in adults; it is a technique that allows full real-time monitoring of the guidewire insertion into the vein without blood aspiration. It is a great advantage in CVC placement, especially with the long-axis in-plane approach. When the literature is reviewed, no study other than a 12 case study in which brachiocephalic vein catheterization related to CVC placement was performed using this technique in children was found. There is no randomized study comparing the "Syringe-free" Long-Axis In-Plane technique with the classic Short-Axis Out-of-Plane technique in pediatric patients.

This study compares these two techniques' efficacy and complication rates in critically ill children requiring CVC placement.

Inclusion Criteria:

• Patients older than 3 months, younger than 15 years old
• Critical illness pediatrics

Exclusion Criteria:

• Patients younger than 3 months and older than 15 years,
• body weight less than 5000 gr,
• anatomical malformation in the neck,
• infection at the intervention site,
• thrombosis