Page 368 - Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice

358 FLUID THERAPY

9. If the catheter has two pliable wings, lay them flat on junction of the needle and catheter hubs, ensuring
the skin surface, and wrap a single piece of white tape that the catheter does not loosen and partially slide
over them and around the limb. This tape should off the needle during manipulation. Never touch
be applied snugly but not tightly enough to occlude the skin at the point of insertion, and never touch
the vein. The tape does not cover the point of entry. the needle/catheter shaft. The needle bevel is
10. If the needle is to remain in place and unobserved, it directed up during the procedure. Advance the nee-
may be prudent to apply a gauze sponge with anti- dle, first subcutaneously and then into the vein. Pen-
septic ointment to the skin penetration site, and etration of the vein often is heralded by a distinct
secure this to the limb with a second piece of 1-inch “pop” as the needle punctures the tough vessel wall
white tape. and by the flow of blood into the needle hub
11. Coil the tubing, and secure the Luer end to the limb (Figure 15-3, B).
with another piece of tape. This coil helps prevent 5. Advance the needle and catheter as a unit for another
movement of the catheter if traction is applied to 3 to 5 mm. This ensures that both the needle and
the tubing. catheter tips are within the lumen of the vein. During
this maneuver, hold the needle shaft as parallel to the
OVER-THE-NEEDLE STYLE long axis of the vein as practical, and lift the catheter
CATHETERS tip away from the deep wall of the vein (as described
Materials Needed for winged needle catheterization, see Figure 15-2).

1. Appropriate catheter Once the catheter tip has entered the vessel, slide the
2. Two pairs of clean examination gloves catheter off the needle and into the lumen of the vein
3. One roll 1-inch waterproof white tape (Figure 15-3, C). If the catheter material is very soft
4. One roll each of appropriately sized stretch gauze, and flexible, an alternative technique is to retract the
stretch bandaging material, and cast padding needle 5 mm back into the catheter and advance the
5. One catheter injection cap, catheter “T” piece, or catheter and needle in unison all the way into the vein.
needleless connection device 6. Your assistant should now release the vein occlusion,
6. Syringe with heparinized saline solution, 1 to 2 U/mL and the needle is withdrawn.
7. Sterile gauze sponges 7. Attach the catheter injection cap, “T” piece, or
8. Single dose of povidone-iodine ointment needleless connector device, and flush the catheter
All materials are arranged ready for use on a clean tray with heparinized saline solution (Figure 15-3, D).
or Mayo stand: 8. Remove any blood or fluid on the catheter hub and
1. Antiseptic ointment applied onto a gauze sponge surrounding skin with sterile or clean gauze sponges.
2. Syringe with heparinized saline attached to “T” piece 9. If a cephalic or lateral saphenous vein is cannulated,
and the air flushed out (if using an injection cap or wrap the catheter hub with a strip of 1.5-to 2.5-cm
needleless connector, purge the air out of that device) (0.5 or 1 inch) white tape, and extend this strip
3. Catheter opened and ready for use around the limb. The tape should be pressed tightly
4. Tape strips made as needed onto the catheter hub but loosely anchored to the
limb (Figure 15-3, E-G). The goal is to secure it to
Procedure the limb, yet avoid wrapping it too tightly. When
1. Prepare the venipuncture site aseptically as described cannulating the medial saphenous or femoral vein
previously. (or any vein at a large, flat surface), the catheter
2. Wash your hands, apply germicidal skin lotion (if not hub should be anchored to the skin with a suture
already done), and don new clean examination to limit in-and-out movement during flexion and
gloves. extension of the limb. To provide a secure anchor
3. A small incision through the skin facilitates insertion without strangulating skin, place a single loop of
of large-gauge catheters (Figure 15-3, A) or place- suture material through the skin under the catheter
ment of the catheter through tough skin (see hub, and create a slightly loose loop incorporating
the Percutaneous Facilitation Procedure section). skin only by tying a secure square knot. Then tie
The techniques for direct and indirect insertion are the free ends of this anchor tightly around the cathe-
the same as noted previously. Indirect catheteriza- ter hub with a surgeon’s knot.
tion is strongly preferred because this forms a sub- 10. Cover the point of insertion with antiseptic ointment
cutaneous tunnel between the point of entry through on a sterile gauze sponge (Figure 15-3, F).
the skin and the point of entry into the vein that 11. If the catheter is to remain in place for more than
serves as a barrier to bacterial migration. 52,56 6 hours, it should be covered with a short, light ban-
4. An assistant restrains the animal and occludes dage that extends 6 to 12 cm (2 to 4 inches) above
the proximal vein. Grasp the catheter firmly at the and below the point of insertion (Figure 15-3, G-J).