passing a 2.5Fr, 2.5-cm catheter (or IV catheter) over the wire and into the arterial lumen FEMORAL ARTERY/VEIN PUNCTURE Indications Arterial or venous blood sampling during resuscitation Venous blood sampling in infants with inadequate peripheral veins Contraindications Avoid femoral punctures in children hypercoagulable states, or cardiac shunts who have coagulation defects, Complications Hematoma of femoral triangle Thrombosis—femoral artery or vein Superficial infection Osteomyelitis/arthritis—proximal femur, hip joint Equipment Butterfly needle (1-in, 21- to 23-gauge needle in a child to years of age or older); syringe on 1.5-in, 19- or 21-gauge needle when child is to 10 years of age or older; 5- to 10-mL syringe; povidone-iodine or chlorhexidine antiseptic solution; 70% alcohol; sterile gauze; blood sample containers Ultrasound may be useful to locate vessel and guide advancement of needle (see Chapter 131 Ultrasound ) Procedure If time allows, apply topical or local anesthetic over the expected puncture site to achieve local anesthesia of the superficial skin Have an assistant restrain the infant This can be done using one of two methods The first method is illustrated in Figure 130.4A , whereby the trunk and contralateral leg are restrained by the assistant and the ipsilateral leg is restrained by the operator The second method is diagrammed with the illustration for suprapubic bladder aspiration (see Procedure in Suprapubic Bladder Aspiration section), in which the assistant leans over the infant with arms pressing on the infant’s arms above and holding the distal thighs below in the frog-leg position Gently flex the knee and externally rotate the hip to identify the landmarks of the femoral triangle Locate the inguinal ligament, and gently palpate midway between the anterior-superior iliac spine and pubic symphysis The femoral artery