Catheters placed in the jugular vein are commonly used to medicate or give fluids to horses in equine hospitals. One potential complication of catheters is thrombophlebitis, or blood vessel wall inflammation resulting in clot formation. When this occurs in the jugular vein, it hampers the flow of blood out of the head. This can cause facial swelling, skin sloughing, and respiratory distress. Jaime Hustace, DVM, a resident in veterinary internal medicine at Oregon State University, discussed how to place an over-the-wire catheter in the lateral thoracic vein, which is in the lower girth area behind the elbow, as an alternative to jugular catheterization at the 2007 American Association of Equine Practitioners Convention, held Dec. 1-5 in Orlando, Fla.

"Lateral thoracic veins are suitable sites for catheterization with many advantages and fewer complications (than jugular veins)," she said. They can take the same size catheter (14-gauge) as is often used in jugular veins, allowing adequate volume of fluids to be delivered to the patient. They are often used at Oregon State for cases with extensive subcutaneous emphysema (air in the soft tissue immediately beneath the skin), neck infection, tracheotomy, loss of suitable jugular vein sites, or those that just need more ports for delivering fluids or medication. However, they are more difficult to access in patients that might be lying down more frequently or in dorsal recumbency for surgery.

"It has often been said that an adequate rate of fluids cannot be administered through the lateral thoracic vein," Hustace commented. "However, we use the same size catheter in that vessel as the jugulars. Running fluids at a higher rate than that through this vessel has been shown to cause an increased risk of thrombophlebitis, so the rate of fluids is sufficient for most treatment protocols."

In addition to lateral thoracic vein site benefits, the use of over-the-wire catheters has its own advantages. Hustace reported that they are more pliable, are often easier to place in this location, have less contact with vessel walls, and cause fewer reactions in vessel walls compared to over-the-needle catheters. However, they are more expensive.

"Complications associated with decreased venous return from the head are avoided if the lateral thoracic vessels are used, and future use of the jugular veins is not compromised," Hustace concluded. "The lateral thoracic vein is a reasonable option for catheterization in the horse and offers an alternative vascular access in patients where traditional jugular venipuncture is not available."

About the Author

Christy M. West

Christy West has a BS in Equine Science from the University of Kentucky, and an MS in Agricultural Journalism from the University of Wisconsin-Madison.

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