Leeches are annelids comprising the subclass Hirudinea. There are freshwater, terrestrial, and marine leeches. Like the Oligochaeta, they share the presence of a clitellum. Like earthworms, leeches are hermaphrodites. Some, but not all, leeches are hematophagous.
The European medical leech, Hirudo medicinalis, and some congeners, as well as some other species, have been used for clinical bloodletting for thousands of years, although most leeches do not feed on human blood, but instead prey on small invertebrates, which they eat whole.
Haemophagic leeches attach to their hosts and remain there until they become full, at which point they fall off to digest. A leech's body is composed of 34 segments. They all have an anterior (oral) sucker formed from the first six segments of their body, which is used to connect to a host for feeding, and also release an anesthetic to prevent the host from feeling the leech. They use a combination of mucus and suction (caused by concentric muscles in those six segments) to stay attached and secrete an anti-clotting enzyme, hirudin, into the host's blood stream.
Some species of leech will nurture their young, while providing food, transport, and protection, which is unusual behavior amongst annelids.
LEECH THERAPY: AN OVERVIEW
The leech is a freshwater amphibious worm, usually black or brown and about 10 cm in length. Of the more than 650 known species in the Hirudo genus, Hirudo medicinalis is used most often in medical therapy. The mouth of the leech has three jaws, each of which has about 100 tiny teeth. It also has a posterior suction device that it uses for stability.
Leech therapy involves an initial bite, which is usually painless (it's thought that leech saliva contains a mild anesthetic); an attachment period lasting 20 to 45 minutes, during which the leech sucks between 5 and 15 mL of blood; and a postattachment period, during which the site continues to bleed. The final stage provides the primary therapeutic benefit; it's caused by components in the leech's saliva, including hirudin, a protein anticoagulant that inhibits thrombin in the clotting process, as well as histamine-like substances that induce vasodilation.
The first medicinal leeches were obtained from streams and rivers, but today they're purchased from companies that function as leech farms. Facilities that don't have established protocols can follow the recommendations of these leech farms. It's advised that leeches be stored at a cool temperature (42° to 45°F [5° to 7°C] and no higher than 68°F [20°C]) in "leech mobile homes" containing distilled water treated with a special salt; some recommend changing the solution every other day.
PATIENT ASSESSMENT
Before leech therapy begins, a thorough assessment should be performed. Also, the nurse should be able to differentiate between arterial insufficiency and venous congestion. In arterial insufficiency, the tissue is pale, turgid, and cool to the touch; capillary refill is either slow (longer than two seconds) or absent. The tissue in venous congestion will have a purple appearance and be engorged, taut, and warm to the touch. Capillary refill will be brisk and instantaneous (less than one second). Although leech therapy may alleviate venous congestion, it's contraindicated in the presence of arterial insufficiency.
The nurse should also ask the patient whether she or he is taking vitamins, herbal supplements, or drugs; some may increase the risk of excessive bleeding or reduced immune response. For example, large doses of vitamin E can prolong prothrombin time, cause coagulopathy, and suppress immunity. Herbal supplements such as dong quai, garlic, ginger, gingko biloba, and ginseng and medications such as aspirin, heparin, warfarin, and nonsteroidal antiinflammatory drugs may increase the risk of hemorrhage.
Caffeine (found in coffee, tea, some sodas, and chocolate) must be eliminated in order to decrease the risk of vasoconstriction. Smoking (and even exposure to secondhand smoke) is absolutely contraindicated because the carbon monoxide and nicotine in tobacco are potent vasoconstrictors.
Contraindications. Leech therapy should not be used in patients who are immunocompromised, those with bleeding disorders such as hemophilia, and those with preexisting arterial insufficiency; all of these conditions pose an extreme risk of infection or excessive blood loss. A patient's refusal to accept blood transfusions is another contraindication, as is unstable medical status. And of course, patients who refuse leech therapy should not receive it.
Patient education. Few patients are willing to have contact with leeches without understanding the benefits of treatment. This obstacle is usually overcome with education.
COMPLICATIONS
Excessive bleeding can occur with leech therapy; it can be controlled by applying direct pressure or topical thrombin. Excessive blood loss may necessitate blood transfusion, so patients should be informed of the possibility. Allergic responses, including anaphylaxis, can also occur. Patients and their families should be alerted to watch for and report allergy symptoms. Scarring may also occur but is usually minimal.
Infection. The most serious complication of leech therapy is infection. The leech's digestive system contains Aeromonas hydrophila, a Gram-negative bacillus that enables the breakdown of ingested blood. Although most infections involving leech therapy are caused by A. hydrophila, infections with Serratia marcescens, A. sobria, and Vibrio fluvialis have been reported. Infections can arise from two to 11 days after therapy begins and can result in abscesses and cellulitis, which can progress in some cases to sepsis. In a five-year retrospective study, Sartor and colleagues found that infections arose in 4.1% of patients who received leech therapy. Prophylactic antibiotics are usually given: double coverage (two antibiotics) during therapy and single coverage (one antibiotic) for two weeks afterward. Established infection is treated with antibiotics such as third-generation cephalosporins, along with aminoglycosides, fluoroquinolones, tetracycline, or trimethoprim. Because infection is a serious adverse effect of leech therapy, the patient and family should also be instructed to observe for and report early signs and symptoms.
Questions and Answers
How much blood does a patient lose during the treatment?
Leeches (European specie Hirudo Medicinalis) can consume between 5 and 15 ml of blood – 4-6 times their body weight in a single feeding. An American specie Macrobdella Decora can consume 10 times less blood than Hirudo Medicinalis. That's why only the European specie is used in medicine. Generally leech therapists use up to 10 leeches so the patient can lose up to 150 ml of blood during the treatment
With 8 leeches the blutverlust for the patient is including to the Nachbluten with approx. 200 to 350 ml blood. "a small leech sucks 2g - the quantity doubles itself 3 g, more largely to 30 g, on average by the postoperative hemorrhage. Generally one counts on an average value of 20 - is limited 30 g total blood loss per leech and to setting 4 - 12 copies in a meeting "
Does a leech bite cause pain?
The bite of a leech is felt by the patients like 2-3 mosquito bites.So the bite of the leech is not painful. The leech saliva is filled with a chemical that contains a painkiller, which stops you from feeling the bite. The saliva also has a chemical, which keeps the blood from clotting.
In which diseases can leeches help?
Thanks to its blood-diluting and container-extending effect the leech is the ideal therapist for blood circulation disturbances.Usually unsatisfactory blood circulation is connected with diseases such as: Thrombose, cramp veins, Haemorrhoiden, cardiac infarct, impact accumulations, calcifying the containers, Tinnitus.
Positive effects could be determined with rheumatism, Arthrose, volume disk problems, pulling, bruises, muscular pains or muscle injuries.
How can I accomplish the leech therapy?
1. Wash hands.
2. Select appropriate personal protective equipment (gloves).
3. Cleanse area with normal saline soaked sterile gauze.
4. Apply leeches with gloved hand on tweezers.
5. Allow leech to attach large posterior end first and direct smaller head end to the desired site. ( Leeches can be loaded into an empty syringe without a plunger “rear end first” and the open end of syringe is placed over the desired site to ensure proper placement. )
6. Apply the other leeches if neseseary.
7. Monitor leeches until they fill with blood (10-20 minutes). Usually the leech falls off itself (if not use salt. Leeches do not like salt and will drop off)
Why does a leech sometimes not want to bite?
With certain site conditions leech bite more badly:
• with cold skin
• with smokers
• with perfume-pure
• with older humans
Remedy is possible through warming up and cleaning the skin. Further measures those are helpful the skin soften and the blood circulation promote. If the leech does not want to bite at all, there is the possibility the skin with a needle to puncture still.
Are there side effects?
With the right execution of leech therapy and attention of all contraindications heavy side effects arise very rarely. Local reactions are possible in the proximity of the point of the bite.Also, cycle weakness occurs relatively more frequently.
In which other cases can leeches be used?
Leeches can relieve blood pooling around a muscle or skin flap better than drugs or other treatments. They are used to keep the blood flow in muscle, skin and fat tissue that has been surgically moved from one part of your body to another. These tissues are also called flaps
Why is leech therapy used instead of other medical treatment?
In some cases, leeches do a better job by removing pooled blood than any other medical therapy.
What are the benefits of leech therapy?
The benefits of leech therapy are not only the amount of blood that the leech removes: It is the anti-blood clotting enzymes in their saliva that allow blood flow from the area where they have been.
Why do some people reject using leeches ?
Many people are afraid of these creatures crawling on their body and biting them.
References
http://journals.lww.com/ajnonline/fulltext/2009/04000/leech_therapy.36.aspx
http://www.leeches.biz/leech-therapy.htm
http://en.wikipedia.org/wiki/Leech
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