For femoral venous cannulation, the lower extremity should be positioned with slight external rotation at the hip and flexion at the knee (frog-leg appearance). A rolled towel under the buttock may facilitate successful venous access, particularly in smaller children. Restraining the leg in the desired position will help to maintain optimal conditions. The femoral artery should be located by palpation and/or ultrasound or, in the pulseless patient, assumed to be at the midpoint between the pubic symphysis and anterior superior iliac spine. Local anesthesia to the area over the intended puncture site should be considered and can reduce the need for sedation and analgesia. During cardiopulmonary resuscitation, pulsations may be felt in the femoral vein or artery; therefore, if cannulation is not successful medial to the pulsations, one should aim for the pulsation during cardiopulmonary resuscitation. The needle should be inserted 1-2 cm below the inguinal ligament, just medial to the femoral artery, and slowly advanced while negative pressure is applied to a syringe attached to the introducer needle (Fig. 27.1). The needle should be directed at a 15-60-degree angle toward the umbilicus, depending on the size of the child, with a flatter approach used in infants than in older children. Once the free flow of venous blood is observed, the syringe should be removed while the needle is carefully stabilized and the guidewire is introduced gently. Some manufacturers include a specially designed syringe (Raulerson) that allows the guidewire to pass through the syringe without removing the needle when placing larger catheters. The guidewire should pass easily with minimal resistance; force should not be applied to overcome a great deal of resistance. Once the guidewire is in place, the Seldinger technique (as described earlier) should be employed. Checking for venous and not arterial placement should be done as described earlier. Some experts recommend confirmation with ultrasound or a lateral abdominal x-ray when femoral venous catheters are placed to document that the catheter has not been placed in the lumbar venous plexus (4). The catheter should be secured with suture or sutureless catheter securement device, as per the hospital policy and procedure, with attention not to kink the catheter at the site of skin entry.

For cannulation of the subclavian vein, positioning of the patient in a head-down position (Trendelenburg) of ˜30 degrees increases upper body venous pressures, which causes distention of the central veins. This positioning also minimizes the risk of introduced air embolism traveling to the brain. Positioning of the patient to optimize cannulation is important, but controversial. The most common positioning technique is to extend the patient’s neck, turn the patients head away from the site of cannulation, and place a rolled towel beneath the patient’s shoulder blades, along the axis of the thoracic spine. However, some authorities recommend keeping the head in a neutral (midline) position in children to optimize the diameter of the vein (5) or slightly flexing the neck and turning the head
toward the puncture site when using the right side approach in infants (6). The shoulders should be maintained in neutral position with the arms at the patient’s side (7).

In the smaller intubated patient, sedation, analgesia, and temporary neuromuscular blockade will facilitate proper patient positioning and reduce complications related to patient movement. In intubated patients, care should be taken to avoid kinking, disconnecting, or dislodging the tracheal tube. Bilateral breath sounds should be verified after proper patient positioning. The infraclavicular approach is most commonly used and will be described here. Alternative approaches include the supraclavicular approach using ultrasound guidance (8). The junction of the middle and proximal thirds of the clavicle should be located, and a small (25 gauge) needle should be used to infiltrate local anesthesia when the patient is not anesthetized. The needle should be introduced just under the clavicle at the junction of the middle and medial thirds and slowly advanced while negative pressure is applied with an attached syringe (Fig. 27.2). The needle should be inserted parallel with the frontal plane and directed medially and slightly cephalad, under the clavicle toward the lower end of the fingertip in the sternal notch. When patients are mechanically ventilated, the needle is advanced while someone holds the ventilator in an expiratory hold position to minimize the risk of pneumothorax. When free flow of venous blood is obtained, the needle should be stabilized and the syringe removed while a fingertip is placed over the needle hub to prevent air entrainment. The guidewire should be introduced during inspiration in a patient on positive-pressure ventilation or during exhalation in a spontaneously breathing patient (to avoid air embolus). The Seldinger technique as described earlier should then be followed. Once the CVC is placed, nonarterial cannulation should be determined, the catheter should be secured with suture or with a sutureless securement device, and a chest x-ray should be obtained to verify catheter location prior to using the catheter and to rule out complications, such as pneumothorax or hemothorax.

Internal jugular catheterization can be achieved via multiple approaches. When available, ultrasound guidance is preferable. Right-sided approaches are preferred owing to potential injury to the thoracic duct on the left side. The carotid artery should be palpated, as it lies medial to the internal jugular vein within the carotid sheath. For all approaches, the patient should be positioned supine and in a slight (15-30 degree) Trendelenburg position, with a roll under the shoulders and with the head turned away from the puncture site. Consider performing beside ultrasound before positioning and draping, and using ultrasound dynamically during needle insertion.

There are three basic approaches to catheterization of the internal jugular vein: anterior, middle, and posterior approaches. In the anterior approach, the needle is introduced along the anterior margin of the sternocleidomastoid muscle, halfway between the mastoid process and sternum and directed toward the ipsilateral nipple (Fig. 27.3A). In the middle approach, the needle enters the apex of a triangle formed by the clavicle and the heads of the sternocleidomastoid muscle (Fig. 27.3B). The skin should be punctured with the needle at a 30-60-degree angle while the needle is directed toward the ipsilateral nipple. For the posterior approach, the needle should be introduced along the posterior border of the sternocleidomastoid cephalad to its bifurcation into the sternal and clavicular heads (Fig. 27.3C). The needle should be aimed toward the suprasternal notch. In all approaches, the needle should be advanced during exhalation to minimize the chance of pneumothorax, and the syringe should be aspirated as the needle is advanced. When the vein is entered and free flow of venous blood is established, the needle should be stabilized and the syringe removed while the hub of the needle is covered to prevent air entrainment. The guidewire should then be introduced and advanced a distance that approximates the distance to the junction of the superior vena cava and right atrium. During guidewire introduction it is helpful to have an assistant watching the patient’s electrocardiogram (ECG) and announcing the provocation of dysrhythmias by the guidewire. Nonarterial placement confirmation, securing, and chest x-ray should be obtained as mentioned before.