Indications, technique and consequences of the sciatic nerve blockade
- 1 Indications for
- 2 Performance techniques
- 3 Preparations for administration
- 4 Advantages and disadvantages
- 5 Contraindications
- 6 Conclusion
During inflammation or infringement of the nerve, the main symptom is a sharp intense pain in the leg, leading to a significant restriction of mobility. The introduction of anesthetics and other drugs directly into the lesion not only removes the painful symptoms, but also provides a therapeutic effect. For the blockade there are certain indications and contraindications, and the manipulation itself is performed by a doctor.
In moderate to mild sciatica, therapy with oral painkiller, anti-inflammatory, antispasmodic action is indicated. Ointments with a similar effect are also prescribed, in some cases, injections. Unlike conventional injections, the blockade is primarily aimed at relieving pain impulses and is used in the following cases:
- diagnosis – with neuropathies, this manipulation allows you to accurately determine the localization and volume of the lesion;
- severe pain that impedes movement, having a permanent character;
- the ineffectiveness of previous treatment with oral and external agents.
Anesthetic blockade is effective both in inflammation and in the pinched nerve, since the painful sensations disappear instantly. However, the effect lasts for several hours, so repeated injections are regularly required. The use of anti-inflammatory drugs gives a lasting therapeutic effect.
Unlike intramuscular injections, which can be done independently at home, the sciatic nerve should be blocked only by a specialist.
Without a medical education, it is almost impossible to choose the appropriate method and place of drug administration. Self-treatment is also fraught with complications: damage to the nerves and blood vessels, needle breakage, inflammation.
According to Voyno-Yasenetsky
It is carried out by rear access, while the patient lies on his stomach. To determine the point where you need to enter the anesthetic, two imaginary lines are drawn. The first is horizontal – across the top of the greater trochanter of the hip bone, the second is vertical along the outer edge of the sciatic hill. The place of their intersection is located directly above the desired nerve.
To avoid infection, the skin is pre-treated with an antiseptic. Then the skin in the injection zone is infiltrated (a 0.25% novocaine solution is used for this). After the sensitivity disappears, novocaine is introduced into the deep-lying tissues through a thin long needle at a concentration of 0.5% in volume from 20 to 40 ml.
The patient is located on the side, the affected limb is located on top, bent at a right angle in the thigh and knee. The needle insertion site is defined as follows: the upper posterior iliac spine and the apex of the greater trochanter are connected by an imaginary line.
From the middle of the line obtained, a perpendicular length of 4-5 cm is held downwards (towards the tailbone). The resulting point at its free end is a place for injection. A long thin needle first anesthetize the skin with subcutaneous tissue, then the underlying tissues.
This technique is used when the patient cannot be rotated (in case of a damaged spine, for example). The patient lies on his back, legs straight. After processing the surgical field antiseptic is marking.
The first line connects the pubic tubercle of the Ilium with its anteroposterior spine. The segment is divided into three equal parts, from the point between its medial and middle parts is held perpendicular. The third line is parallel to the first, passing through the outer edge of the greater trochanter. Its connection with the perpendicular is the place of insertion of the needle.
The technique of the injection in this case requires special care. After anesthetizing the skin with fiber, a needle with a length of at least 8 cm is inserted in the direction of the femur prior to contact with it. Then it is slightly pulled back and plunges medially, by the bone, to a depth of 5 cm. In order to prevent the anesthetic from entering the artery, an aspiration test is performed before the medication is injected.
Preparations for administration
For blockade, anesthetics are used – Novocain, Lidocaine – in various concentrations. For example, to anesthetize the injection site, several milliliters of 0.25% Novocain are injected subcutaneously. Directly in deep-lying soft tissues of 0.5-1% solution.
Sometimes the introduction of nonsteroidal or hormonal anti-inflammatory (Diclofenac, Dexamethasone) is carried out in a similar way. In some cases, muscle relaxants or narcotic painkillers are used.
Advantages and disadvantages
The undoubted advantage of blocking the sciatic nerve over other types of therapy is an almost instant effect. The pain disappears in a few minutes, freedom of movement and ability to work return. Since the drug is administered topically, a small amount of it enters the bloodstream (respectively, a minimum of side effects is manifested). There are also few contraindications to this method, in contrast to drug therapy with oral agents.
The disadvantages of manipulation are primarily its probable complications:
- damage to the sciatic nerve by the needle;
- puncture of the femoral artery;
- needle breakage (in contact with bone or muscle spasm);
- bladder puncture;
However, negative effects are excluded if the blockade is performed by a doctor in compliance with the techniques and rules of antiseptics. A disadvantage can also be considered a side effect of drugs in the form of a decrease in blood pressure, dizziness, weakness, and allergic reactions.
Blockade of the sciatic nerve is contraindicated in certain chronic diseases and acute conditions. It can not be carried out in patients younger than 18 years old, pregnant and lactating women, people with diabetes, osteoporosis, renal failure, hypotension, active tuberculosis.
Contraindications are also hypersensitivity to the drugs used, the tendency to allergic reactions.
Nerve blockade in the event of infringement or inflammation is the fastest way to relieve pain. This manipulation, when performed by a specialist, taking into account contraindications, is safe and has no side effects.
However, to achieve a stable therapeutic effect, it is necessary to eliminate the cause of sciatica, for which other conservative and surgical treatment methods are used.