中心静脈カテーテル挿入: 鎖骨下静脈

The subclavian vein offers several advantages: the catheter can be placed quickly using anatomic landmarks, making it ideal in trauma settings when cervical collars block internal jugular access. Additionally, subclavian CVC placement has lower infection and thrombosis rates compared to internal jugular and femoral approaches, making it a preferred choice for many practitioners.

The Seldinger technique involves introducing a catheter into a vessel over a guide wire inserted through a thin-walled needle. An 18-gauge needle cannulates the subclavian vein, then a guide wire is passed through it. The needle is removed, a dilator passes over the wire to dilate tissue, and finally the catheter is advanced over the wire until properly positioned within the vessel.

Place your non-dominant index finger in the sternal notch, then identify the middle third of the clavicle with your thumb. The insertion site is one fingerbreadth below the medial portion of the middle third of the clavicle. The needle is aimed toward the index finger at the sternal notch, targeting where the vein passes between the clavicle and first rib.

The Trendelenberg position, with the patient supine and feet elevated, engorges the target vessel and decreases the risk of air embolus. A rolled towel under the medial scapula can accentuate physical landmarks. However, excessive shoulder retraction should be avoided as it may compress the subclavian vein by decreasing the space between the clavicle and first rib.

The most significant risk is pneumothorax due to anatomic proximity of the lung dome just deep to the subclavian vein. Additionally, inadvertent arterial puncture poses a challenge because the clavicle impedes access to the subclavian artery, making effective vessel compression difficult. These risks can be minimized with sterile precautions, anatomic knowledge, and fluidity with the Seldinger technique.

The right subclavian vein is preferred because the left side has a thoracic duct and higher pleural dome, increasing procedural complexity and risk. The first rib on the right acts as a barrier to the lung underneath, helping prevent pneumothorax. These anatomic differences make right-sided access safer and more straightforward for practitioners.

After advancing the catheter to approximately 15 cm in adult men, the guide wire is removed. A sterile syringe is attached to the distal port to aspirate and confirm blood return, then the lumen is flushed with sterile saline. This process is repeated for each lumen on multi-lumen catheters. Finally, the catheter is sutured in place and a sterile dressing is applied over the insertion site.