Cephalic and Saphenous Vein Catheterization
||Any of the catheters that can be placed in
the jugular vein can also be placed in peripheral veins. Short catheters sold for
placement in peripheral veins such as (a) and (b), have the catheter on the outside of the
needle so the hole in the vein wall made by the needle is smaller than the catheter. The
catheter fills the hole in the vein wall and there is minimal leakage of blood around the
|c) is a butterfly
catheter (no, butterflies are not free, they cost ~$2.00). The
"catheter" portion that goes in the vein is a rigid needle. Butterfly
catheters are used for short term, small volume, infusions such as the
administration of CaparsolateTM used to treat heartworm disease.
Because of its rigidity,
it is not useful for long term fluid administration as the needle may lacerate the vein.
(d) is a catheter that has the conformation of a butterfly catheter but the catheter is
flexible teflon rather than metal. The catheter has a wire stylet that is removed after
placement. This style of catheter is very useful for placement in peripheral veins in
small dogs and cats and breeds of dogs with short, crooked legs. It can also be used to
drain fluid or air from body cavities. The flexibility of the catheter after the stylet is
removed, reduces the chance of organ laceration.
Have all necessary supplies
ready before placing the catheter. Supplies needed in addition to the catheter include one
inch tape, (2 pieces of sufficient length to encircle the limb), an injection cap and a
10-12 ml syringe filled with saline or heparinized saline. If the catheter is to be left
in place for several days, a small amount of antiseptic or antibiotic ointment on a gauze
pad should be placed over the catheter puncture site before bandaging the catheter in
The catheter placement site
should be widely shaved and the skin scrubbed with antiseptic solutions, using the same
technique as for preoperative skin preparation.
||Notice that the holder is standing on the
side of the dog opposite the leg that is being catheterized. The dog is restrained close
to the body of the holder. The muzzle is held away from the face of the holder and the
person placing the catheter. She is reaching over the dog to hold off the vein and can
apply downward pressure over the dog's back, if needed to keep the dog in sternal
recumbancy. The dog's leg is being held at the elbow to prevent her from pulling back her
leg. The individual holding the leg places the thumb of the same hand across the dorsum of
the limb to occlude venous blood returning from the leg, causing the vein to distend with
blood. In some cases the vein will be clearly visable, in other cases you may palpate the
|The holder places her thumb firmly
on the medial side of the most proximal aspect of the limb. The thumb is
"dragged" to the dorsal aspect of the leg which will "roll" the
cephalic vein to the dorsum of the leg. Pressure is applied with the thumb to restrict
blood flow returning from the distal limb, causing the vein to engorge with blood. The
catheter should be placed as distal in the vein as possible. If the catheter is too
proximal, its tip will lay at the elbow. As the animal withdraws its leg, flow through the
catheter may cease. You can catheterize the cephalic vein on the medial side of the limb,
at a location distal to the junction of the cephalic and accessory
Before making the puncture, the
venipuncturist can lay the thumb of the hand that is holding the leg, adjacent to the vein
to reduce vein movement when it is being punctured.
||If the catheter you are using has a solid
cap, remove it. Some catheters have "flashback" caps with holes in the center to
allow air in the catheter to be displaced by blood when the venipuncture is made.
"Flashback" caps may be left on the catheter when the puncture is made.
||Puncture the skin and vein in one swift movement. If you are too
gentle, the vein moves away from the catheter. Once the vein is
punctured, blood will flow through the needle that is inside the
|Move the thumb and forefinger of the hand holding the leg toward each other
and grasp the needle of the catheter, still holding the leg in the same
hand. By holding the needle this way, if the patient pulls his leg away
from you, the catheter will not be pulled out. Using the other hand
(right hand for a right handed person) gently rotate the catheter off
the needle, advancing the catheter into the vein. As the needle is
removed, blood will flow from the catheter. At this time the holder
should remove their thumb from the dorsum of the leg (continuing to hold
the leg). If the holder presses firmly over the vein just proximal to
the tip of the catheter, less blood will flow from the catheter, making
the taping procedure less bloody.
||After the stylette is removed, an
injection cap is placed and the catheter is flushed well with saline or heparinized
saline, to assure patency. Dry the leg and the catheter with gauze before applying tape.
The injection cap should not be taped into
the bandage so that it can be easily removed later.
Taping a cephalic catheter in place:
over the end of the tape to create a tab for easier removal.
||A second piece of tape placed under the
cap will allow easier removal and replacement of the cap and prevent hair from touching
the tip of the catheter.
injection cap can be removed for direct connection of a fluid administration set (a)
to the IV catheter, or the cap can be
left on the catheter and the fluid administration set attached using a 20 gauge hypodermic
needle inserted through the cap. The administration set is "looped" and taped to
the leg (b)
. This reduces the
chance of accidental removal of the catheter if the administration set is pulled.
||A hypodermic needle with plastic cover,
attached to an injection cap can be taped to the IV pole or the fluid bag or bottle. When
fluids are temporarily stopped, the injection cap is placed on the end of the catheter and
the needle with plastic cover is placed on the end of the IV administration set to keep
the tip of the tubing sterile.
||Movement of the leg can occlude fluid flow
through the catheter. If needed, a splint such as the pictured Mason-meta splint can be
used to keep the limb extended to maintain a constant fluid flow rate. The leg and splint
can then be bandaged or the splint can be taped to the leg at both ends, leaving the
catheter exposed. The use of IV infusion pumps reduces the need to keep the limb extended.
Fluid pumps can often overcome the resistance created by positional changes.
To place a catheter or obtain blood
from the lateral saphenous vein, the animal is positioned in lateral recumbancy. The
holder is holding off the vein with her right hand. Some dogs have a prominant medial
saphenous vein which can be catheterized or sampled. To access the medial saphenous vein,
the animal is held in lateral recumbancy but the holder applies pressure on the medial
aspect of the leg closest to the table. *
||The technique for placing a catheter in
the lateral saphenous vein of the dog is similar to the technique for cephalic placement.
Notice the venipuncturist has placed her thumb adjacent to the vein to stabilize it.