pulsatile femoral artery or 0.5 cm medially for the vein, whichever is desired Apply constant suction to the syringe as the needle is advanced into the thigh to ensure blood is obtained on entering the vessel The assistant should work to avoid uncontrolled leg movements by the infant leading to loss of alignment of the needle and vessels If unsuccessful, withdraw the needle to just below the skin surface and reattempt vessel puncture after shifting the medial or lateral alignment of the needle tip After obtaining the sample, stop suction on the syringe After needle withdrawal, the assistant should apply constant manual pressure on the puncture site for minutes with sterile gauze PERCUTANEOUS FEMORAL VEIN CATHETERIZATION Indications Emergency access to central venous circulation See Chapter 131 Ultrasound for discussion of ultrasound guidance The femoral vein is more accessible than the internal jugular or subclavian veins during resuscitation Complications Inadvertent arterial catheterization Arterial or venous laceration Infection (especially if placed in an emergency situation without reliable use of infection control technique) Hematoma Catheter or wire fragment in central circulation Equipment Commercial tray containing introducer needle, 5- to 10-mL syringe, guide wire, no 11 blade scalpel, dilator, and catheter; 3Fr (younger than years of age) or 4Fr (2 to years old) or 5Fr (older than years of age); sterile drapes and gloves; povidone-iodine or chlorhexidine antiseptic solution; sterile gauze pads; use larger single-lumen set in trauma patients; ultrasound machine if available Procedure If time allows, apply topical or local anesthetic over the expected puncture site to achieve local anesthesia of the superficial skin Restrain the lower extremities and trunk of the child Externally rotate the hip to facilitate palpation of the femoral triangle Consider use of a towel roll under the gluteal muscle to improve exposure of the vein Palpate the femoral artery 1.5 cm below the inguinal ligament, halfway between the anterior-superior iliac spine and symphysis pubis