Anesthesia Student Survival Guide.pdf - Index of

iv, GAstric tube, ArteriAl & centrAl line PlAcement techniques ● 233
Physiology
The artery has innervation and is tender when punctured. Using lidocaine liberally
around the vessel ensures patient comfort and keeps the vessel from
spasming if it is contacted by the needle tip but not entered. This is crucial
because it will preserve the lumen of the vessel for subsequent attempts at
cannulation.
Technique
There should be a sterile skin preparation and drape, and many advocate
gowning, wearing a hair cover and mask. The use of audio Doppler or ultrasound
may help localize the vessel. Palpation with gloves is necessary to
maintain aseptic technique, but it makes it harder to palpate the maximal
pulsation.
Generally, the artery is entered with a 20 g catheter. The angle of incidence
is approximately 30°. The bevel should be up when inserted. After a flash is
seen, the needle should be advanced 3-5 millimeters to transfix the vessel. The
needle is removed, and the catheter should be withdrawn until brisk bleeding is
evident. A guidewire is then inserted and the catheter advanced over the wire.
A line is then attached and the catheter is secured. Care is taken to exclude air
from the line, catheter hub, and catheter itself to prevent distal embolization
into the fingers. Problems, complications, and artifacts of arterial monitoring
will be discussed in Chap. 10.
Central Venous Line (CVL)
Anatomy
Knowledge of the relevant anatomy is critical to avoid serious complications
during CVL placement. The sites of insertion commonly used are internal
jugular, subclavian, and femoral veins.
Internal Jugular Vein
Figure 15.2 shows the anterior approach of cannulation of the internal jugular
vein (IJ). The internal carotid artery is posterior and medial to the jugular
vein on either right or left side, although there is considerable variation. The
carotid may lie either directly posterior to, or, in a small percentage of cases,
posterior and lateral to the vein. When inserting IJ catheters, there is always a
risk of carotid puncture.