Central venous and arterial access in children — OSCE

Station brief (candidate)

• Choose and justify the central venous site for this thrombocytopenic child in septic shock, and state which site you would avoid and why.
• Talk through the ultrasound-guided Seldinger technique at your chosen site, naming each step.
• Describe how you would confirm correct catheter tip position, and how you would manage an arterial puncture during the attempt.
• Outline your central line-associated bloodstream infection prevention bundle. [1] [8]

Scenario detail

The child is a 3-year-old (14 kg) in septic shock, cold and shut down, on rising doses of adrenaline through a tenuous peripheral cannula. The platelet count is 35 and the coagulation screen is mildly deranged. You have been asked to place the central line. The examiner will ask you to talk through your site selection and preparation, then probe a complication. [8]

Expected candidate performance

1. Site selection: Chooses the femoral vein because it is compressible, pneumothorax-free, and suited to the emergency setting; explicitly avoids the subclavian vein because the subclavian artery cannot be compressed and a puncture bleeds into the chest; names the femoral vein as medial to the artery in the NAVL sheath relationship. [3] [8]
2. Seldinger technique: Identifies the femoral vein in short axis as the medial, compressible, non-pulsatile structure; applies chlorhexidine and full barrier precautions; raises a skin wheal with lidocaine; advances the needle under ultrasound; confirms venous blood; passes the guidewire, withdraws the needle, dilates, and railroads the catheter over the wire; removes the wire, aspirates and flushes all lumens, secures the line. [1]
3. Tip confirmation and arterial puncture: Confirms the tip at the cavoatrial junction on a chest radiograph or by ultrasound tip navigation; for an arterial puncture, withdraws the needle and applies firm sustained proximal pressure for several minutes, reassesses under ultrasound, and repositions before reattempting; never passes a wire into an artery. [8] [11]
4. CLABSI prevention: Full barrier precautions at insertion, chlorhexidine skin antisepsis, chlorhexidine-impregnated dressing, scrub-the-hub before each access, no routine flushing, and a daily review of line necessity with prompt removal. [12]
5. Safety net: Arranges monitoring in an intensive-care setting, documents the procedure and any complication, and plans removal of the line as soon as it is no longer needed. [8]

Marking domains

• Correct site selection justified by bleeding risk, with explicit avoidance of the subclavian site in thrombocytopenia.
• Accurate stepwise ultrasound-guided Seldinger technique with the wire controlled at all times.
• Correct tip confirmation and a safe, rehearsed response to an arterial puncture.
• Complete CLABSI prevention bundle including a daily review of line necessity.
• Recognition that the freshly placed line belongs in an intensive-care setting and that the line is removed when no longer needed. [1] [12]

Common fails

• Choosing the subclavian site in a thrombocytopenic child without recognising that the bleeding cannot be compressed. [8]
• Omitting ultrasound guidance or failing to confirm the vein as compressible and non-pulsatile before needling. [1]
• Passing a guidewire into an artery, or failing to hold firm sustained pressure after an arterial puncture. [8]
• Forgetting tip confirmation, or omitting the daily review of line necessity from the CLABSI bundle. [11] [12]