Although it is always best to utilize the least invasive access, central venous access is often required in the PICU. This chapter addresses central venous access and arterial access first and then addresses peripheral venous access and interosseus access. Ultrasound considerations are incorporated throughout the chapter.
Central versus peripheral access: Peripheral access should be used whenever possible, unless specific indications for central venous access are present.
Unable to achieve peripheral access
Large volume resuscitation
Need for vesicant, irritant, or hyperosmolar or highly concentrated solutions (including total parenteral nutrition [TPN], electrolyte replacement, greater than 12.5% dextrose, pH <5 or >9, or osmolarity >600 mOsm/L)
Need for vasoactive support
Need for hemodynamic monitoring, including central venous pressure, pulmonary artery pressure, or mixed venous saturation monitoring
Frequent blood draws
Need for prolonged access (chemotherapy, prolonged antibiotic course)
Increased bleeding risk secondary to thrombocytopenia or coagulopathy.
Predisposition to sclerosis or thrombosis. Contraindicated in a vessel with a known thrombus.
Bleeding: Assessment for thrombocytopenia and coagulopathy should occur prior to line placement
Infection: Use sterile technique with full barrier to minimize infection
Embolization of intravascular thrombus, guidewire, or air
Vessel perforation
Materials
Sterile gloves, gown, drapes
Surgical hat, mask
Catheter (see Table 8-1 for size and length considerations)
Caps for each catheter lumen
Introducer needle
Syringe (non-Luer Lock) to attach to introducer needle and two to three additional 3-mL syringes
Guidewire (at least double the length of the catheter; verify that guidewire passes through needle prior to starting procedure)
Scalpel
Tissue dilator
Suture
Kelly clamp
Additional syringes
Medications
Lidocaine 1% for skin numbing (and appropriate needle for superficial injection)
Chlorhexidine (>2 months) or iodine (<2 months) for skin preparation
Catheter selection
Preparation
Sterile procedure: Use cap/mask, gown, sterile gloves
Prepare the area with 2% chlorhexidine (>2 months) or 10% povidine-iodine (<2 months)
Catheter preparation
Flush all ports and caps with normal saline or heparinized saline
Clamp lumens after flushing
Anesthesia
For use of systemic sedation or analgesia, ensure NPO status (6 hours for solids; 4 hours for clear liquids).
Inject local anesthetic (1% lidocaine) into the tissues at and below the venipuncture site. Withdraw prior to injection to avoid intravascular injection.
Seldinger technique (Figure 8-1)
Puncture the skin using an introducer needle attached to non-Leur Lock syringe.
Advance until blood return is free-flowing, then remove syringe, keeping introducer needle in place. Place finger over open lumen on needle to avoid air entry.
Insert guidewire through introducer needle, keeping one hand on the guidewire at all times.
Until the guidewire is removed, one hand should be kept on the guidewire for each subsequent step.
Guide wire should enter without resistance and, if met with resistance, needle or guidewire should be redirected prior to reattempting advancement.
When guidewire is in place, using a scalpel, make a small incision at the venipuncture site. Remove the introducer needle with the guidewire remaining in place.
Introduce the dilator over the guidewire. Use a twisting motion to advance through the skin as needed. Remove the dilator with the guidewire remaining in place.
Thread the catheter over the guidewire, retracting the guidewire through the catheter as needed until the guidewire is visible on the other side of the catheter.
Once the catheter is in place, remove the guidewire.
Aspirate blood through each port to ensure free flow. Flush each port. Take care to avoid introducing any air through the catheter.
Suture the catheter in place.
Attach caps to the catheter lumens.
Blood gas
Transduce pressure
Imaging
Chest x-ray for internal jugular (IJ) or subclavian placement to verify positioning and evaluate for pneumothorax
Abdominal x-ray for femoral placement to verify positioning
Remove as soon as the indication for a central venous line (CVL) is no longer present
Remove sutures and retract catheter with pressure at the insertion site after removal
Materials
Ultrasound machine
High-frequency linear probe
Ultrasound gel
Preparation
Cover probe
Place gel over ultrasound probe
Vessel identification and confirmation
Veins compress more easily than arteries
Veins have thinner walls than arteries
Arteries have pulsatile flow; veins do not
Prescan along length of vessel to ensure its depth, course, and patency
Center vessel on screen
Confirm successful catheterization with catheter/wire visualized in vessel
General technique
Position the ultrasound machine in the operator’s direct line of site (usually on the opposite side of the patient’s bed with the cord draped across the patient)
Orient the probe so that the left side of the probe corresponds to the left side of the ultrasound screen
Ultrasound probe held in operator’s nondominant hand
Needle held in operator’s dominant hand
Short axis/transverse approach
Orient probe with its long axis perpendicular to the path of the vessel
Vessel will appear as black/anechoic circle with white/hyperechoic rim on screen
Brace fingers of hand holding probe on patient to ensure stability
Insert needle at skin at midpoint of probe of the long axis of the probe
Identify needle tip as bright white/hyperechoic dot on screen
Advance or slide ultrasound probe a few millimeters while advancing the probe
Adjust needle direction to ensure it is in line with the vessel
Ensure needle tip remains in view by tilting the probe back and forth
Poke needle through superficial wall into vessel
Shallow needle angle to allow passage of wire or catheter
Long axis/longitudinal approach
Orient probe with its long axis parallel to the path of the vessel
Vessel will appear as black/anechoic tube with white/hyperechoic edges on screen
Brace fingers of hand holding probe on patient to ensure stability
Insert needle into the skin proximal to and at the midpoint of the short axis of the probe
Identify needle tip and shaft as hyperechoic oblique line on screen
Keep nondominant hand in place while vessel is in view
Advance needle under direct ultrasound guidance
Poke needle through superficial wall into vessel
Shallow needle angle to allow passage of wire or catheter
Short axis vs. long axis approach
Short axis approach:
Allows simultaneous visualization of intended and neighboring vessels
Any point of the needle (tip and shaft) appears as a hyperechoic dot; if needle tip is not followed, one may poke inadvertently through the vessel
Some operators may find it difficult to manipulate the probe with their nondominant hand
Long axis approach:
Allows visualization of the entire vessel and needle
The hand–eye coordination necessary to keep probe still while advancing the needle along its plane may be challenging
Limited space of a patient’s short neck may preclude placing the probe in the long axis and a longitudinal approach
Advantages
Avoids device in neck or chest
Able to control bleeding locally with pressure
Drawbacks
Unable to obtain a true mixed venous saturation, unless a long catheter is placed
Central venous pressure (CVP) monitoring affected by intra-abdominal pressure; femoral CVLs should not be placed in the setting of acute intra-abdominal process or trauma
Difficult when anatomic landmarks are distorted
Excessive stooling increases infection risk
Anatomy (Figure 8-2)
Inguinal ligament runs from anterior superior iliac spine to the pubic symphysis
Femoral artery and vein run in parallel and should be entered below the inguinal ligament
“NAVEL” describes the structures from lateral to medial of importance: nerve, artery, vein, empty space, lymphatics