The animals should be applied in adequate numbers to the general area of maximal congestion. One (1) or two (2) leeches may be sufficient to treat the skin of a partially degloved or replanted finger, whereas a large flap may require 6 or more depending on initial clinical response. The head (or biting end) of the animal can be recognized by its searching movements, while the tail end is used mostly as a sucker for attachment.
1. Clean patient's skin thoroughly with soap and water to remove all substances with strong odor or taste such as traces of operative prep fluids or saline. Rinse cleansed areas with distilled, non-chlorinated or bottled water.
2. Recommended method for applying leeches:
Remove the plunger from a 5 cc plastic syringe and place the leech in the barrel of the syringe. Invert the barrel, placing the open end on the wound site, where you want the leech to attach. Once feeding commences, remove the syringe.
3. To prevent leech wandering, form a barrier by cutting a 1 cm hole in the middle of a dampened gauze square and locating the hole in close contact with the area to be treated.
4. Steer the leech's head to the area to be treated. Attachment generally occurs quickly; however, if the leech is reluctant to bite, make a small needle prick on the skin to produce a tiny droplet of blood (which should result in enthusiastic attachment) or try another leech. Sugar or other sweet substances are not necessary. It should be noted that persistent resistance to feeding is often indicative of poor arterial supply.
5. Once the leech is attached, it will likely remain safely in place until fully distended. The gauze square can be removed and used elsewhere without disturbing the animal;however, it is important that the site be checked continuously to insure that the leech hasn't moved.
6. When the leech has finished its meal, usually within 45 minutes, it will detach itself from the bite site.