The first experiments on the use of spinal anesthesia date back to 1898, but this method of anesthesia was widely used much later. To use this method, the doctor must have certain knowledge in the field of anatomy of the spinal cord and its membranes.
Epidural and spinal anesthesia
These methods of anesthesia are regional. During their implementation, an anesthetic is injected into a special area located near the spinal cord. Due to this, the lower half of the body is “frozen”. Many do not know if there is a difference between spinal and epidural anesthesia.
The procedure for preparing and conducting anesthesia with these methods is similar. Indeed, in both cases, an injection is made in the back. The fundamental difference is that spinal anesthesia is called a single injection, and epidural (epidural) is the installation of a special thin tube through which an anesthetic is injected over a certain period.time.
But technique is not the only difference between these two methods of anesthesia. Spinal anesthesia is used in cases where it is necessary to achieve a short-term effect. Depending on the type of drugs used, the duration of pain relief can vary from 1 to 4 hours. Epidural anesthesia is not limited in time. Pain relief will continue as long as the anesthetic is delivered into the body through the installed catheter. Often this method is used to relieve the patient of pain not only during surgery, but also in the postoperative period.
Operation principle
Epidural and epidural anesthesia is a regional anesthesia in which drugs are injected into the epidural space of the spine. The principle of its action is based on the fact that the drugs used through the dural clutches enter the subarachnoid space. As a result, impulses passing through the radicular nerves to the spinal cord are blocked.
After all, the drug is injected in the immediate vicinity of the trunk with nerve cells. Namely, they are responsible for the appearance of pain in various parts of the body and conduct them to the brain.
Depending on the injection site, it is possible to disable motor activity and sensitivity in certain areas of the body. Most often, epidural anesthesia is used to “turn off” the lower half of the body. To do this, it is necessary to introduce an anesthetic into the intervertebral space between T10-T11. Foranesthesia of the chest area, the drug is injected into the area between T2 and T3, the upper half of the abdomen can be anesthetized if an injection is made into the region of the T7-T8 vertebrae. The area of the pelvic organs "turns off" after the introduction of an anesthetic into the space between L1-L4, the lower limbs - L3-L4.
Indications for the use of regional anesthesia
Epidural and spinal anesthesia can be used both separately and in combination with the general one. The latter option is used in cases where thoracic surgery (on the chest) or long-term surgery in the abdominal region is planned. Their combination and the use of anesthetics can minimize the need for opioids in patients.
Separate epidural anesthesia can be used in the following situations:
- pain relief after surgery;
- local anesthesia during childbirth;
- the need for operations on the legs and other parts of the lower half of the body;
- caesarean section.
In some cases, only epidural anesthesia is used. It is used when operations are necessary:
- on the pelvis, thigh, ankle, tibia;
- for hip or knee replacements;
- with a fracture of the femoral neck;
- hernia removal.
Spinal anesthesia can be used as one of the treatments for back pain. It is often done after surgery. It is also used invascular surgery in cases where it is necessary to carry out intervention in the lower extremities.
Pain relief in childbirth
More women are using epidural or spinal anesthesia to avoid painful contractions. With the introduction of an anesthetic, pain disappears, but consciousness is preserved in full.
Epidural anesthesia in childbirth is often used in developed countries. According to statistics, it is used by about 70% of women giving birth. This type of anesthesia allows you to anesthetize the entire process of childbirth. At the same time, this does not affect the fetus in any way.
Despite the fact that childbirth is a natural physiological process that does not require outside intervention, more and more women insist on being given anesthesia. Although during childbirth, the body produces a shock dose of endorphins. They contribute to natural pain relief, because these hormones are able to provide emotional uplift, suppress feelings of fear and pain.
True, the mechanism of endorphin production depends on the condition and mood of the woman. For example, prolonged labor with severe pain negatively affects both the woman in labor and the unborn baby. In addition, a woman's blood pressure may increase, a breakdown may begin, and disruption of the main muscle, the heart, may occur. In such cases, pain relief is necessary.
But only in a planned manner can an epidural anesthesia be performed. Contraindications to its implementation are quite common. But don't use it in emergencies.also because its action does not come instantly. It may take half an hour from the start of the administration of anesthetics to complete anesthesia.
Nuances of preparation
If possible, the patient is preliminarily prepared for anesthesia. If epidural (epidural), spinal anesthesia is planned, then in the evening the patient is given up to 0.15 g of Phenobarbital. If necessary, a tranquilizer may also be prescribed. As a rule, doctors use the drugs Diazepam or Chlozepid. In addition, about an hour before the introduction of anesthesia, intramuscular injections of Diazepam or Diprazine are shown, Morphine and Atropine or Fentalin can also be prescribed.
Also a mandatory step is the preparation of sterile styling. For its implementation, napkins (both large and small), sterile rubber gloves, gauze balls, needles, syringes, catheters, two tweezers and two glasses for anesthetic solutions are needed. It is also important to prepare everything necessary in order to be able to eliminate possible complications. With such anesthesia, the possibility of severe malfunctions in the circulatory and respiratory systems cannot be ruled out.
2 syringes are pre-prepared, one of which should be 5 ml and the other 10 ml. Also, the medical staff prepares 4 needles, 2 of which are necessary for anesthesia of the skin area where the main injection will be made. Another one is needed in order to inject an anesthetic and conduct a catheter, and the last one is for taking an anesthetic medication intosyringe.
Administration of anesthesia
Spinal and epidural anesthesia is given to the patient who is sitting or lying on his side. As a rule, the latter position is used much more often. In this case, the patient should bend the back as much as possible, pull the hips to the stomach, and press the head to the chest.
The skin in the injection area is carefully treated and lined with sterile wipes. This is done in the same way as before the operation. In the planned site of the puncture, the skin is anesthetized. In addition, to facilitate the passage of the needle through the skin, it is recommended to make a small puncture with a narrow scalpel.
Specialists identify two methods of how the epidural spinal space can be accessed: median and paramedial. At the first, the needle is inserted in the gap between the axillary processes. After passing through the skin and fatty tissue, it rests first on the supraspinous, and then on the interspinous ligament. In older patients, they can become calcified, making insertion of the needle much more difficult.
The lateral or paramedial method provides that the injection is made in the border area located between the vertebrae. It is carried out from a point located 1, 5 or 2 cm from the spinous processes. But this method is used when it is not possible to puncture the canal in the middle way. It is recommended for obese patients with sclerotic ligaments.
Features of the "epidural"
Before scheduled surgeriespatients with an anesthesiologist decide what kind of anesthesia will be used. But many patients want to figure out for themselves what epidural and epidural anesthesia is. What is the difference between these methods, it will not be possible to find out. After all, these are two names for the same method of pain relief, in which the anesthetic is gradually introduced into the body through a catheter.
The doctor must know the nuances of the puncture. For example, to perform epidural anesthesia, the needle must pass through the ligamentum flavum. To do this, the mandrin is removed and a syringe is attached, in which there is a solution of sodium chloride, so that an air bubble remains. Once the needle enters the ligament, the air bubble will appear compressed. But it straightens out as soon as the tip enters the epidural area.
Also, the anesthesiologist must be aware of other methods to check that the needle is correctly positioned. The fact that everything is normal is indicated by the absence of cerebrospinal fluid in the needle after its patency was checked with a mandrin. Also, make sure that a small amount of saline injected does not flow back through the needle after the syringe is disconnected. But this is not a complete list of verification methods. The doctor must carry out a comprehensive diagnosis in order to make sure that the needle is correctly positioned.
Epidural anesthesia requires the use of a catheter. Its introduction, as a rule, does not present any difficulties. After selection and testing for patency, it is advanced through the needle into the epidural space. Thereafterthe needle is gradually removed, and the catheter is fixed by closing the exit site with a bactericidal patch or a sterile dressing.
Used medicines
To minimize possible complications during epidural anesthesia, it is important to choose the right dose of anesthetic and correctly carry out the puncture procedure itself. For anesthesia, purified solutions of anesthetics are used, which do not contain preservatives.
In some cases, Lidocaine is used for epidural anesthesia. But they also use drugs such as Ropivacaine, Bupivacaine. Under the supervision of a highly qualified experienced physician and if indicated, opiate-related drugs may be added to them. It can be such medicines as "Morphine", "Promedol". But the dosage of these funds is minimal. It can't even compare to the one used for general anesthesia.
When an anesthetic is injected into the epidural region, the latter spreads through it in various directions. It passes up, down and into the paravertebral tissue through the intervertebral lateral foramens. At the same time, when figuring out what the concentration of Dikain should be for epidural anesthesia, it must be remembered that the area of anesthesia will depend on the amount of solution, the intensity of administration and dosage. In addition to the above, they can also use the means "Xikain", "Trimekain", "Markain". For complete anesthesia, about 25-30 ml of solutions of these anesthetics can be used. But this numberconsidered the maximum.
Necessary restrictions
Despite the fact that epidural anesthesia is considered one of the safest, it still has contraindications. These include:
- tuberculous spondylitis;
- pustules on the back;
- traumatic shock;
- organic lesions of the central nervous system;
- complex deformities of the spine, its diseases and pathological injuries;
- intestinal obstruction;
- cardiovascular collapse caused by peritonitis;
- general serious condition of the patient;
- decompensation of the heart;
- children's age;
- hypersensitivity to anesthetic components;
- exhaustion of the body.
Possible problems
But do not forget that epidural anesthesia is not always painless and without consequences. Contraindications, complications that occur should be clarified before going to the operating table.
It should be understood that the technique of performing such anesthesia is complex, so the qualification of the doctor is crucial. The most dangerous is the occurrence of deep collapse after spinal or epidural anesthesia. Most often, this condition occurs when the dura mater is damaged. Because of this, a blockade of sympathetic innervation occurs, as a result, vascular tone decreases, and severe hypotension develops. However, this condition can also develop if performed correctly.anesthesia in cases where a large proportion of the anesthetic is injected, counting on anesthesia of a wide area.
But problems can develop in the postoperative period. These include:
- the beginning of an inflammatory purulent process in the spinal canal (the cause, as a rule, is a violation of the rules of antiseptics);
- headache and discomfort in the back area;
- paresis of the lower extremities, pelvic organs (may develop due to damage to the roots of the spinal cord by the needle).
If patients are anesthetized using "Morphine", then they need to be monitored more closely. Indeed, sometimes such epidural anesthesia leads to respiratory depression. There are no specific contraindications for using this method. But it is worth remembering that the risk of respiratory depression increases with increasing doses of morphine.
Features of spinal anesthesia
Despite the similarities, there are significant differences between epidural and spinal anesthesia. For example, the position of the needle after the ligamentum flavum is not so important. As soon as the needle passes through the dura mater, the doctor feels a sense of needle failure. The catheter is not installed with this type of anesthesia.
When making a puncture, it is necessary to ensure that the needle does not go too far and does not damage the roots of the spinal cord. The fact that the tip has already entered the subarachnoid space can be confirmed if the mandrin is removed. In this case, the cerebrospinal fluid will begin to stand out from the needle.liquid. If it comes intermittently or in insufficient quantities, then you need to slightly change its position by rotating. After the correct installation of the needle, they begin to introduce anelgizing agents. Their dosage is less than with epidural anesthesia.
