Catheterization Techniques: IV, Urinary, and Feeding Tube Placement and Maintenance

Catheterization Techniques: IV, Urinary, and Feeding Tubes

Quick Answer: Catheterization is a core veterinary nursing skill spanning intravenous (IV), urinary, and enteral feeding access. Every catheter demands aseptic placement, secure fixation, scheduled flushing, and q4–6h site monitoring. The cephalic vein is the default IV site; the Foley catheter is the default indwelling urinary line; and feeding tube choice depends on duration (nasogastric short, esophagostomy intermediate, PEG long-term).

Catheterization establishes reliable access for fluid therapy, drug administration, nutritional support, urinary diversion, and hemodynamic monitoring. The veterinary technician selects the catheter type and site based on patient size, condition, venipuncture accessibility, and the duration of anticipated need. Every catheter is a foreign body: aseptic technique and disciplined maintenance are non-negotiable.

Intravenous Catheterization

Site Selection and Vein Comparison

Aseptic Placement Protocol

1. Clip a wide area around the insertion site—failure to clip enough hair is the most common cause of contamination.
2. Surgical scrub with chlorhexidine or povidone-iodine, working outward in concentric circles; allow contact time per manufacturer.
3. Don sterile gloves for jugular and central lines; clean gloves are acceptable for peripheral cephalic placement when using a sterile catheter kit.
4. Distend the vein with a holder applying gentle pressure proximal to the site.
5. Insert the catheter at a 15–25° angle with the bevel up; advance, then slide the stylet back while threading the catheter into the vein.
6. Secure with tape strips and a padded bandage; label with date, time, gauge, and initials.

Gauge Selection

Catheter gauge is the lumen diameter—the lower the number, the larger the catheter. Match gauge to patient and flow requirement:

• Large dogs, rapid fluid bolus or transfusion: 16–18 G cephalic or 14–16 G jugular
• Medium dogs: 18–20 G cephalic
• Cats and small dogs: 22–24 G cephalic or saphenous
• Neonates: 24–26 G, often saphenous or jugular

A common VTNE trap is using too small a catheter when rapid volume resuscitation is required—flow rate scales with the fourth power of radius, so gauge dominates viscosity.

Maintenance and Flush Schedule

• Flush every 4–6 hours with heparinized saline (1–2 U/mL) or sterile saline to prevent fibrin buildup and clot formation.
• Inspect the site every 4–6 hours for heat, swelling, pain, redness, or discharge—early phlebitis signs.
• Change the T-connector/extension set every 72 hours and whenever contaminated.
• Change peripheral catheters every 72 hours or sooner if complications appear; jugular lines may stay longer with strict aseptic care.

Trap callout: Never aspirate an IV catheter. Negative pressure traumatizes the endothelium, pulls the vessel wall against the catheter tip, and accelerates thrombosis. If patency is in doubt, flush gently; resistance means stop.

Complications

• Phlebitis: vein warmth, swelling, cord-like firmness—remove immediately.
• Thrombosis/occlusion: flush resistance; do not force.
• Infection/cellulitis: erythema, discharge, fever—culture and remove.
• Dislodgement/extravasation: swelling at site, fluid SQ rather than IV—remove, apply warm compress, elevate limb.

Urinary Catheterization

Catheter Types Comparison

Placement Technique

1. Aseptic prep of the external genitalia; sterile gloves and lubrication.
2. Gently advance the catheter into the urethra; resistance warrants stopping, repositioning, and instilling sterile lube—never force.
3. For Foley: inflate the balloon with the volume printed on the hub (usually 3–5 mL sterile saline); connect to a closed collection bag.
4. Secure the external tube to the patient with tape or suture to prevent traction.

Maintenance

• Closed drainage system is preferred to reduce nosocomial UTI risk; open drainage requires gloves and sterile technique for each emptying.
• Monitor urine output hourly in critical patients; record color, clarity, volume.
• Empty the bag with aseptic technique, avoiding touching the port.
• Flush the catheter only if obstructed and per veterinarian order.

Feeding Tubes

Tube Comparison

Placement and Maintenance Highlights

• NG/NE: confirm placement by radiograph or by aspirating stomach contents and testing pH (gastric pH <4); incorrect tracheal placement is the catastrophic trap—always verify before feeding.
• E-tube: secure with a Chinese finger-trap suture; flush with water before and after each feeding; keep the stoma clean and dry; change the bumper site dressing daily.
• PEG: allow 12–24 h maturation before first feeding; feed liquid diet warmed to body temperature; flush with water after each feeding; monitor stoma for discharge, redness, or infection.

Complications

• NG: displacement into trachea, epistaxis, nasopharyngeal irritation.
• E-tube: tube migration, stoma infection, regurgitation.
• PEG: peritonitis (the most serious), tube leakage, stoma infection, tube obstruction.

Trap callout: Never advance a feeding tube against resistance—if resistance is met, stop, withdraw slightly, and flush. Forced advancement risks esophageal or gastric perforation. Always confirm placement radiographically before the first feed.