Vascular Access

Peripheral Venous Access

  • Generally easiest and safest method of obtaining venous access
  • Pediatric animal arrest models show no significant difference between peripheral and central access for onset of drug action and peak drug levels1
  • Most common catheter sizes are 22-24 gauge for newborns/infants and 18-20 gauge for older children
  • Most common sites include dorsum of hand or foot, antecubital veins, and sometimes scalp veins.
  • The external jugular vein can be a useful site for obtaining peripheral access and is best exposed by placing the child in Trendelenburg and rotating the neck. Ultrasound can be used to help guide cannulation. The right side is preferred.

Central Venous Access

  • ASA CVL Practice Guidelines
  • Central venous access provides more reliable access as well as the ability to deliver large volumes of fluids or potentially irritating/high osmolarity medications such as calcium chloride or dextrose concentrations greater than 12.5% 
  • Central venous access also allows collection of labs and monitoring of variables such as central venous pressure and central venous oxygen saturation

Catheter Selection

  • Flow rate through a catheter is directly proportional to the internal diameter of the catheter and inversely proportional to its length. Resistance to flow decreases by the fourth power of the change in radius as the radius of the catheter increases. This is described by Poiseuille's Equation. Hence, for pushing fluids rapidly, you want a large, short catheter. Thus, a peripheral IV may be better than a triple lumen PICC line. 
  • Catheter size is based upon both patient size and anticipated use. In general, newborns or very small infants <5 kg may require 3Fr catheters. However, in most other PICU patients, 4Fr catheters will suffice with 5-7Fr catheters being used in patients >25 kg that may need aggressive fluid resuscitation.
  • Catheter length will depend on the site with the goal of an upper CVL (IJ, subclavian) terminating at the SVC/RA junction and a femoral CVL generally terminating in the external or common iliac vein. These distances can be approximated before choosing a catheter length.
  • Number of lumens should be appropriate for anticipated use (i.e. double or triple lumen if anticipating multiple infusions or worsening trajectory vs. single lumen simply for extended IV antibiotic use). Limiting the number of lumens may reduce the rate of catheter related bloodstream infection, although this is not clear.2,3
  • Site: The most common sites used for central venous access include the femoral vein, subclavian vein, and internal jugular vein. The femoral vein is the most commonly accessed site for resuscitation due to its location away from the site of chest compressions and airway control. While traditionally thought of as a "dirtier" site associated with more infections, femoral venous cannulation has been associated with lower rates of complications and recent meta-analyses from adult populations have called this teaching into question.4,5  More recently, a RCT from France (Parienti et al, NEJM 2015) demonstrated lower rates of bloodstream infection and symptomatic thrombosis but higher risk of pneumothorax with subclavian CVC vs. IJ or femoral CVC. This was done in 3027 critically ill adult patients. 

Technique

  • Positioning for central venous catheterization is critical.
    •  For femoral venous access, a roll can be placed under the buttocks to better expose the femoral vein and the hip should be slightly flexed and externally rotated. Needle puncture occurs medial to the femoral artery pulsation (NAVEL) generally at the level of the femoral crease (1-2 fingerbreadths below the inguinal ligament). 
    • For internal jugular access, the child should be placed in 30 degrees of Trendelenburg with the head turned away from the site of cannulation in slight extension. Generally the right internal jugular is preferred because the path is more direct and there is less risk of pneumothorax or damage to the thoracic duct. Needle puncture occurs at the apex of the triangle formed by the clavicle and the sternal and clavicular heads of the sternocleidomastoid (for standard medial/central approach).  
    • For subclavian access, the child should be in Trendelenburg with a rolled towel placed between the scapula along the spine to extend the back. Needle puncture should occur at the juncture of the medial and distal third of the clavicle

Catheter Positioning

  • The catheter tip for a "high" line (IJ, subclavian, PICC) should terminate at the SVC-RA junction. Catheters in the upper SVC are associated with a higher risk of thrombosis and catheters in the RA may increase the risk of catastrophic perforation. Radiographically, the SVC-RA junction occurs approximately 2 vertebral bodies below the carina (Baskin et al, J Vasc Interv Rad 2008) 1.5 cm below the carina, although there is variability particularly in younger children. Hence, in general, the catheter tip should be at or slightly below the carina.


Peripherally Inserted Central Catheter (PICC)

  • PICCs are often used for longer term access (weeks to months) and may be a reasonable option in many of our patients
  • Catheter selection depends on the size of the patient and the intended use. 
    • Drawing blood: PICCs less than 3Fr in size cannot be used to draw blood
    • Contrast injections (ie CT scans): Power PICCs (5Fr) should be inserted if this is anticipated
    • In general, neonates and small infants require 1.9Fr PICCs. 3Fr PICCs can be used in infants and toddlers although they are single lumen. 4Fr double lumen PICCs are the most common PICCs inserted in the PICU and will work for most patients. 5Fr triple lumen power PICCs can be used in older/larger children (~10 yrs +, 35 kg+) in those that may require contrast injections
  • PICCs are inserted into the basilic and cephalic veins, with the right side generally preferred for its more direct approach
  • At the UM PICU, fellows may attempt PICC placement on one arm but if unsuccessful, should generally reserve the other arm for the vascular access PICC team. If the vascular access team is unsuccessful, interventional radiology can place more difficult PICCs


Intraosseus Access

  • Used for emergent access or when access is urgently needed and peripheral access has not been readily achieved. IO access should be used over central venous access in emergent situations as it is achieved more rapidly and easily
  • Sites used include: Proximal tibia, distal femur, distal tibia (medial malleolus), proximal humerus (adults)
  • Any intravenous drug or fluid can be given through the intraosseus route, including vasoactive medications
  • Diagnostic studies such as glucose, hemoglobin, pH, PCO2, bicarbonate level, sodium, BUN, chloride, creatinine, serum drug levels, and cultures are generally accurate while PaO2, white blood cell count, potassium, AST, ALT, and ionized calcium may not be accurate.
  • Contraindications include fractured or previously penetrated bones as well as extremities with vascular interruption. Relative contraindications include infection at the cannulation site, patients with osteogenesis imperfecta or osteoporosis, or patients with right to left intracariac shunts (increased risk of marrow emboli). 
  • Intraosseus access is meant to be a temporary rescue measure and should be removed after venous access is obtained or at 24 hours (increased risk of osteomyelitis), whichever is earlier. 
  • Procedure videos are available to demonstrate placement.

Umbilical Venous/Arterial Access

  • Umbilical venous/arterial catheters may be a good option for access in newborns even up to 2 weeks of age, particularly as other access options (PICC) may not permit blood draws. Hence, it is worth discussing with the neonatologists should a neonate require central access
  • CDC recommendations suggest UVC/UAC's be limited to 14 days if possible, although there is no significant evidence to suggest independent increased risk of infection with catheter duration.

Complications

  • Bleeding
  • Arterial puncture- consider transducing the pressure before dilating if unsure
  • Arrhythmia
  • Air embolism
  • Thoracic duct injury (left SC or left IJ approach)
  • Pneumothorax/hemothorax
  • Infection-topic in and of itself but highlights to prevention include the Pronovost checklist  (hand hygiene, chlorhexidine, maximal barriers, avoiding femoral venous insertion, remove unnecessary CVCs). CDC CLABSI Guidelines
  • Thrombosis/PE
  • Catheter embolization
  • Myocardial perforation
  • Nerve Injury

Securing Chest Tubes



References