Techniques of stimulation of the acupuncture points

NEEDLING (ZHEN)

In traditional AP, 9 types of needles were used. Some of these were like scalpel blades or lances and must have inflicted severe pain on the animal. These are seldom if ever used in western AP today. To avoid unnecessary suffering, the finest needles possible should be used. In practice, this means using 25-32 gauge needles in small animals and 19-25 gauge needles in large animals.

The length of the needles depends on the species of animal and on the location of the points to be needled. Points over bony areas, such as the scalp, face, ears and distal limbs require the shortest needles. Those over the thorax, abdomen and lightly muscled areas require medium length needles and those over heavily muscled areas, such as the lumbar area, the hindquarter (buttock and thigh) area and the heavy muscles of the shoulder area require the longest needles.

In general, needle lengths ranging from 10-50 mm should suit all purposes in small animals and needles 10-100 mm should suit all purposes in large animals. In human surgery under AP analgesia, occasionally very long (up to 250 mm) needles are placed parallel to the incision site, one on each side of the wound. This method is seldom used in veterinary surgery.

The needles can be of two types (a) special solid, stainless steel AP needles, made of very high quality steel wire and (b) standard hypodermic needles.

a. AP needles: The cheapest needles are made in China and Taiwan but many other eastern and western countries make AP needles. They are available through APsupply houses. The cheapest source is via Hong Kong mail-order houses, such as Mayfair Medical Supplies, which accepts international credit cards and orders can be placed by Fax (852-721-2851).

Human-type needles are suitable for small animals but they are too fine for use in large animals. The problem is that muscular twitching and spasm, which frequently occurs during the needling session (especially when the needles are electrically stimulated), can twist the fine needles into bizarre shapes (L-shapes, Z-shapes and U-shapes etc), making them difficult to extract and destroying them for future use. AP needles are expensive and between 1 and 20 may be required during a session. If 6-12 needles are bent or destroyed each time, the cost in one year can be high. Therefore, the thicker needles (19-25g) are used in large animals. Even then, some of them will be bent during therapy. Chinese (Yuan Li) needles, 30 mm long and 21 gauge wide are ideal for use in large animals. Similar vet needles made by the Richter Company, Wels, Austria, are also available.

b. Standard hypodermic needles have the advantage of being very cheap and disposable but they have the disadvantage of causing more pain and they may introduce dirt or skin into the tissues because they have a lumen. They also cause more tissue damage and bleeding.

Before use, each needle should have been properly sterilised. It should be checked to ensure that it has no physical defects such as a blunted or hooked tip, bent or rusted body or loose handle. The points are clipped and cleaned with alcohol or other antiseptic solution. In my opinion, unless the skin is visibly dirty, attempts to clean it by alcohol swabbing or by aerosol spray are a public-relations exercise more than a useful hygienic procedure. Clipping makes the points easier to find on subsequent visits. Occasionally clipping is omitted, as some owners may object to their animal being clipped in up to twenty places.

Insertion of needles: The animal should be restrained adequately. Hypodermic needles can be inserted to the required depth in one swift, firm movement. In nervous or dangerous horses, it may help to have a twitch placed on the horse's upper lip, or ear, and to apply counter-pressure to the point (using, for instance, the plastic needle cover) with one hand as the needle is thrust home with the other hand.

AP needles need a different technique. They are inserted by a push-twirl technique in two stages: the first movement to penetrate the skin and the second to place the needle to the required depth in the tissues. With longer needles, it is useful to hold the needle shaft with one hand about 25 mm from the tip (using a cotton-wool bud or piece of sterile tissue) and to push-twirl the handle of the needle with the other hand. Alternatively, a stainless steel or plastic needle guide can be used. Needle guides are hollow tubes, about 10-13 mm shorter than the needle. The guide is placed firmly on the point and held with one hand. The needle is inserted into the tube and the needle-handle, protruding from the guide, is tapped firmly with the finger of the free hand to drive the needle 10-13 mm deep. The guide is then removed and the needle is advanced to the correct depth.

It is not possible to give an exact depth or direction for needle insertion: these vary between points (within species) and between points (between species). The direction of insertion depends on the body region being needled. Over muscular areas, the needle is usually inserted at 90^o to the skin, deep into the muscle. Over bony areas and on Earpoints, the needle is inserted perpendicularly until- the skin is penetrated and then is advanced subcutaneously. One should not normally needle the periosteum (except in cases where this is specifically indicated) or the ear cartilage. Accidental striking of bone can bend the tip of the needle, making it difficult to extract and destroying the tip.

Penetration of the human ear cartilage can cause a chronic auricular chondritis which can be very difficult to cure. In animals (because ear AP is less commonly used than in humans) this problem is uncommon but, it is safer to avoid penetrating the cartilage. Penetration of the thoracic or abdominal cavities is normally forbidden, except in specific cases, such as aspiration of fluid or releasing gas from the viscera etc. Therefore, when needling points over the thorax and abdomen, the needles are usually inserted at 45^o, to reduce the risk of accidental penetration into the cavity. Penetration of major arteries (such as the carotid) or of sensitive organs such as the eye is forbidden.

The depth of insertion also varies within and between species. In large animals the needles can be inserted up to 100 mm deep in certain points, such as those over heavy muscles, or when the needle is obliquely inserted in certain points on the head. However depths of 25-50 mm would be more usual. Certain points are merely pricked to a depth of 3 mm or so. The exact depth and direction of needle insertion is described for each point in the vet AP textbooks, such as those of Westermayer, Brunner, Klide and Kung etc.

In small animals heavy muscle groups would be needled to depths 10-50 mm, depending on the amount of muscle. Pricking of certain points and shallow needling (up to 10 mm deep) of other points is applied as in the human textbooks. (The Chinese have no texts on small animals and Western vets have to approach these species by reference to similar human conditions).

In humans and in animals, the most active points are over peripheral nerves especially main nerves, such as the trigeminal, facial, radial, median, ulnar, sciatic, spinal nerves etc. Nerves running on and in the muscles are also very important. The acupuncturist deliberately inserts the (very fine) needles directly through these nerves. Nerve stimulation (by twirling the needle clockwise and anticlockwise and pecking it up and down) causes very specific sensations (De Qi) in humans. Shooting sensations (paraesthesia), numbness and heaviness must be elicited, otherwise the needle is not exactly in the correct position. Once the needle is correctly in the nerve point and De Qihas been attained, care is taken to avoid further pecking motion with the needle to avoid physical damage to the nerve. This is more important when hypodermic needles (with sharp cutting edges) are used.

When the needle is correctly placed and stimulated, a local reflex muscle spasm grips the needle tightly, "like a fish taking the bait". The response is felt both by the patient and the acupuncturist. Animals, however cannot tell the acupuncturist what they feel. Thus, vets have to seek the objective signs of strong nerve stimulation. Animal reaction to this may differ, but shivering, local muscle twitch, vocalisation, lifting of a limb, attempts to escape, bending of the back, swishing the tail, lowering of the head and defensive reaction may occur during strong stimulation. The needle should be tightly gripped by the tissue, as in humans.

Tonification and sedation techniques: Classic methods of manipulating the needle are different if the diagnosis indicates a definite excess of Qi in a meridian (SHI diseases = excess Qi) or definite deficiency of Qi in a meridian (XU diseases = deficient Qi). These topics are discussed further in the paper on "Holistic concepts of health and disease". In SHI diseases use XI (Sedation) technique. In XU diseases use BU (Tonification) technique. In both methods, the needle is manipulated until De Qiarrives (i.e.) until sensation of tingling, numbness, heaviness and gripping sensation needle occurs.

In BU (tonification) technique the needle is thrust in heavily and rapidly. It is rotated (twirled) with small amplitude and low frequency and is lifted gently and slowly before the next rapid and heavy thrust.

In XIE (sedation) technique the needle is thrust in gently and slowly. It is then twirled strongly (large amplitude) at high frequency and is lifted forcibly and rapidly before the next gentle and slow thrust. The techniques are summarised below.

Duration of needling: Needles are usually left in position for 10-30 minutes in conditions such as rheumatism, muscle pain, arthritic lameness etc. Occasionally the vet may be too busy to wait for up to 30 minutes until the needles are withdrawn. In these cases the farmer or owner may be instructed to twirl the needles for 10 seconds every 2-4 minutes, until 10-30 minutes have elapsed and to remove the needles then. (In this case, disposable needles are used). In some cases, for instance rhinitis, conjunctivitis, shock etc, duration of needling can be very short, 10-60 seconds.

Textbooks seldom indicate whether quick needling or longer duration of needling is required. In general, for paralysis and painful conditions (especially of the muscles) long duration of needling (up to 30 minutes) is indicated, whereas for most other conditions a quick needling is sufficient. Some Chinese sources claim that if De Qi is obtained, there is no advantage to be gained from leaving the needles in situ for 10-30 minutes, except in certain chronic conditions, such as peripheral nerve damage. Thus, a short, quick, strong needling may replace the longer, more gentle method in many diseases.

Needles falling out: If (having been properly planted at the beginning) a needle falls out during treatment, it is usually left out. Relaxation of the muscles around the needle is taken to indicate sufficient stimulation for that point.

Other types of needling: The textbooks describe other types of needle - the blood needle and the fire needle.

The blood needle is a thick needle or lance used to puncture points over superficial blood vessels to allow a small amount of blood to escape. A mild haematoma around the puncture would may cause longer stimulation of the point than if a fine needle were used. However this method has few adherents at best.

The fire needle is a thick needle which is heated before use by burning a swab soaked in alcohol on the needle. It is then plunged in the tissues, taking special precautions. This method is seldom used in the West.

Moxa-needle: This method is used widely, especially in muscle rheumatism and "Cold Diseases", such as chronic infertility in cattle. ln this method, standard APneedles are inserted into the points as usual. A piece of moxa about 20 mm long and 20 mm diameter is pushed aver the handle of the needle and is ignited. The moxa burns slowly for 5-10 minutes and the heat is transferred to the needle and the tissues. This method is not painful and does not usually cause noticeable tissue damage. At the end of the session the animal may be sweating profusely near the needle site and occasionally in other areas if multiple needles are used. (It is well known that heat applied to the trunk will cause reflex sweating of the face in humans).