Download VASCULAR ACCESS Introduction This section discusses the

VASCULAR ACCESS
L. Mathers, MD, S. Kache, MD
Introduction
This section discusses the placement of peripheral IVs, central venous catheters,
arterial lines, and intraosseous access. Children may benefit from systemic sedation or
topical anesthesia with 1% lidocaine or topical EMLA cream during line placement.
Peripheral IV Placement
Peripheral IVs consist of a catheter-over-a-stylet and can be inserted in one of two
methods.
1. Initial entry method: insert the device until blood flow is seen, then slowly
advance the catheter over the stylet
2. Through & through method: pass the device completely through the vessel;
slowly withdraw until blood flow is seen, then advance the catheter over the
stylet
Once a vein is “blown”(defined as bleeding within the external sheath of the vessel, or
adjacent to the vessel), it is best to seek another target vessel.
Peripheral IVs in pediatric patients should not be used for • Repeated blood sampling. In older, larger patients, the great saphenous or
antecubital veins can serve such a purpose.
• Delivery of vasoactive agents (except in emergencies)
• Bolus infusions of calcium or potassium salts
A catheter can be placed in nearly any visible or palpable vein in the superficial fascia.
If possible, one should choose a vein that will cause minimum inconvenience and pain
to the patient – e.g. if the patient is left-handed, avoid veins in the left hand; an IV
placed in the foot may restrict the patient’s ability to walk
Common potential veins that can be cannulated include:
Great saphenous vein: begins at a vascular arch on the dorsum of the foot, and
collects to pass anterior to the medial malleolus at the ankle.
The external jugular vein: [see images below] crosses the lateral surface of
sternocleidomastoid (SCM), from anterior to posterior. It is a good choice for
cannulation because it is often clearly visible, but is not well anchored and may slide
around.
Basilic vein: begins on the lateral side of the wrist, and ascends the forearm, crosses
the elbow, and descends just above the elbow to join the brachial vein.
Cephalic vein: begins on the lateral side of the wrist (intern’s vein), and then
ascends the medial forearm and arm to the groove between the deltoid and
pectoralis major muscles.
Vascular Access
1
Veins on the dorsum of the hand: there is individual variability of venous patterns,
but in most patients 1-3 large veins can be visualized in the web spaces between
digits 2-3, 3-4, and 4-5.
Percutaneous Catheters (PICC lines)
These devices are introduced through a peripheral vein and are advanced deeply into
the venous system until the tip of the catheter lies in a central vein. These catheters
can therefore be treated like a CVC.
Central Venous Catheter (CVC) Placement
Indications:
• Aggressive volume resuscitation, administration of multiple medications
• Continuous infusion of inotropes, vasopressors
• Frequent lab draws
• Monitoring of the central venous pressure (CVP) as an indicator of the patient’s
fluid status / pre-load to the right heart
• Difficult peripheral access
CVC are available in multiple sizes (4 – 8.5 french), lumens, and lengths. The
appropriate size catheter is determined based on a patient’s age and weight. Sedation
Vascular Access
2
should be considered for a CVC placement since it will improve the ease and safety of
line placement along with increasing patient comfort.
Technique: Seldinger technique
• If the patient is receiving sedation for the procedure, assure proper
arrangements are made
• Position patient appropriately
• Palpate the appropriate landmarks to assure optimal position of patient
• Practioner performing the procedure should wear a hat, mask, a sterile gown,
and sterile gloves
• Organize the required equipment: appropriate line kit & ultrasound
• Pre-flush the catheter and all lumens with saline to prevent an air embolus
• Prep and drape the area in a sterile fashion
• Administer 1% Lidocaine for topical anesthesia with a 25ga needle
• Place the introducer needle under the skin and gradually advance at
approximately a 30° - 45° angle until the vein is entered as noted by easy blood
draw in the syringe
• Once the needle is in the vein, disconnect the syringe and place the guidewire
into the needle (monitor for arrhythmias with wire placement while cannulating
the IJ or SC)
• Remove the needle
• Make a small skin incision at the site of wire entry
• Place the dilator over the guidewire and advance through the skin and into the
vessel
• Remove the dilator
• Place the catheter over the wire; NEVER LET GO OF THE WIRE
• Remove the wire
• Confirm that all lumens can draw blood and be flushed easily
• Cap the lumens
• Suture the line in position
• Place a sterile dressing over the line site
• Check an X-ray to check location – particularly with an IJ or SC placement
The veins most commonly used for CVC access are as follows.
Femoral Vein
• Anatomy: The femoral vein, artery, and nerve (VAN) lie medial to lateral under
the mid-portion of the inguinal ligament. The anatomic landmarks are relatively
easy since the femoral arterial pulse can be easily palpated. Once the line is
placed, the catheter tip can reach either the iliac veins or the inferior vena cava.
• Patient position: A small role placed under the patient’s hips with the leg being
externally rotated for younger patients and straight for older patients provides
the optimal position.
• Advantages: In patients with severe bleeding diathesis, pressure can easily be
held at the site.
Vascular Access
3
•
Disadvantages: The vessel can be small in neonates and infants and greater
concern for venous congestion exists.
Internal Jugular Vein (IJ)
• Anatomy: The IJ lies just lateral to the common carotid artery; therefore, the
carotid pulse can be palpated while cannulating the IJ. As the IJ descends
toward the clavicle, it begins to diverge laterally away from the carotid artery.
The needle can be introduced midway in the neck along the medial margin of the
sternocleidomastoid muscle (SCM), using the mastoid process and the clavicle as
reference points for the muscle. The catheter can also be placed between the
two heads of t he SCM. The final location of the catheter tip is in the SVC.
• Patient position: A small role placed either under the patient’s shoulders or
along the middle of the spine with the head turned away from the side of line
placement provides the optimal position.
• Advantages: Ultrasound guided CVC placement in the IJ improves success rate
and decreases complications as demonstrated by many studies. Also, in patients
with severe bleeding diathesis, pressure can easily be held at the site.
• Disadvantages: Pneumothorax, air embolus – particularly in spontaneously
breathing patients, and arrhythmias are the risks of greatest concern.
Subclavian Vein (SC)
• Anatomy: At about the midpoint of the clavicle, the SC vein passes deep to the
clavicle and continues medially in that position until it joins the IJ vein. One
reliable approach to cannulating the SC is to pass a needle just deep to the midpoint of the clavicle and advance the needle medially, taking care to direct the
needle so that it passes along the deep surface of the clavicle. Once completed,
the catheter tip should be located in the SVC.
Vascular Access
4
•
•
•
Patient position: A small role placed either under the patient’s shoulders or
along the middle of the spine with the head falling inferiorly and the arm pulled
caudally provides the optimal position.
Advantages: It is often very comfortable for patients since either neck (IJ) or leg
(femoral) movement is not impacted.
Disadvantages: Pneumothorax, air embolus – particularly in spontaneously
breathing patients, and arrhythmias are the risks of greatest concern. Also, the
subclavian artery passes parallel to the SC vein, and inadvertent entry of the
artery cannot be compressed. Therefore, in patients with a bleeding diathesis,
the subclavian vein is not the optimal choice.
ARTERIAL CATHETERIZATION
Indications:
• Repeated arterial blood samples
• Continuous measurement of arterial blood pressure
Technique:
• Cannulated similar to a peripheral IV
• Seldinger technique
Arterial Sites of Cannulation:
Radial and Ulnar arteries can both be easily palpated in the wrist. The radial artery,
located laterally, is usually the site of choice due to its’ reliable location. The ulnar
artery, which is located laterally, is larger. Ideally, both vessels should not be
Vascular Access
5
attempted in the same period to assure adequate blood flow is maintained to the
hand.
Dorsalis pedis can usually be easily palpated in the mid-foot.
Posterior tibial artery can be palpated as it passes posterior to the medial malleolus.
Femoral arterial cannulation is similar to femoral venous line placement (see above).
It is the artery of choice in patients that present in shock and have poor distal
pulses.
Axillary artery can be used, particularly in neonates and infants
Vascular Access
6
Intraosseous Access (IO)
• Indications: During emergency situations, i.e. an arresting or rapidly
decompensating patient, in which intra-venous access cannot be quickly
established. An IO is equivalent to any other venous access and can be used to
deliver all medications and for volume resuscitation.
• Anatomy: The IO needle accesses bone marrow sinusoids which drain into
medullary venous channels and eventually into systemic venous circulation.
• Potential Sites: proximal tibia, distal femur, distal tibia, iliac crest, and sternum.
Due to ease of access, the most commonly accessed sites are the proximal tibia
and the distal femur.
• Technique: Locate the flat portion of the proximal, medial tibia or of the distal
femur and clean the area with an anti-septic solution. Hold the needle over the
insertion site at a 90° angle and firmly twist the needle in position. The pressure
required will vary based on the patient age and therefore the bone density. As
the needle is being advanced, the practitioner will feel a “pop” as they enter the
marrow space. At this point, stabilize the needle in place, remove the stylet, and
aspirate blood into a syringe. Once the position is confirmed by the aspirate,
then the IO can be used to administer IV-fluids and medications
• Contra-indications: The IO should not be placed at the site of a fracture, an area
with cellulites or a burn.
• Complications: If the calf is becoming tense with a proximal tibial IO placement,
than another IO should be inserted at a second site.
Once adequate venous access is established, the IO should be removed and the site
should be dressed with a clean bandage. An IO is not recommended for long-term
venous access.
Vascular Access
7