March 29, 2009

Researchers have found that shaving an area of horse's skin over the jugular vein before the insertion of a catheter is the best course to reduce the risk of infection.

Intravenous catheters are commonly used to administer ongoing fluid therapy, give medications and take blood samples.

However, they do carry risks, in particular thrombosis and infection. Even healthy skin carries bacteria that could cause problems if introduced with the catheter, so it is important to disinfect the site beforehand.

A study at Glasgow University looked at techniques used to prepare the skin for inserting catheters. Tim Geraghty and others at the Faculty of Veterinary Medicine reported their work recently in the Veterinary Record.

They compared disinfection protocols using two commonly used antiseptic solutions - povidone iodine and chlorhexidine - and assessed whether clipping or shaving the hair before disinfecting helped reduce the bacterial count.

Equine Science Update reports that they took swabs from the skin overlying the jugular veins before and after clipping or shaving the hair and after disinfection.

Samples taken before any treatment had bacterial counts of up to 300,000 cfu /ml. Organisms recovered included bacteria that are part of the normal skin flora such as staphylococci (67%), streptococci (15%), and micrococcus spp. They also found environmental contaminants including enterobacteriaceae, aspergillus, and mucor.

Shaving produced a significant reduction in bacterial numbers, even without disinfecting. The authors suggest this was probably due to the physical removal of bacteria by the shaving process.

Both disinfectants, chlorhexidine and povidone iodine, gave a significant reduction in bacterial count, regardless of whether the hair had been clipped or shaved first.

In conclusion, the authors recommended clipping or shaving the hair over the jugular vein before disinfecting. As well as cleaning the skin in preparation for disinfecting. This makes the vein more clearly visible, making it easier to introduce the catheter.

But they do suggest that if necessary, the skin can be disinfected effectively without clipping or shaving.

Assessing techniques for disinfecting sites for inserting intravenous catheters into the jugular veins of horses.
TE Geraghty, S Love, DJ Taylor, J Heller, DK Mellor, KJ Hughes.
Vet Rec (2009) 164, 51-55