Spinal and epidural( peridural) anesthesia - what's the difference? Application, contraindications, possible complications
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 some knowledge in the field of anatomy of the spinal cord and its membranes.
Epidural and spinal anesthesia
These anesthesia methods are regional. During their conduct anesthetic is injected into a special area located near the spinal cord. Due to this, the lower half of the trunk is "frozen".Many do not know if there is a difference between spinal and epidural anesthesia.
The procedure for preparing and carrying out anesthesia by these methods is similar. After all, in both cases, an injection is made in the back. The principal difference is that a single injection is called spinal anesthesia, and epidural( epidural) is the installation of a special thin tube through which an anesthetic is injected over a period of time.
But the technique of execution is not the only difference between these two methods of anesthesia. Spinal anesthesia is used in those cases when it is necessary to achieve a short-term effect. Depending on the type of drugs used, the duration of anesthesia can vary from 1 to 4 hours. Peridural anesthesia is not limited in time. Anesthesia will continue until an anesthetic is injected into the body through an established catheter. Often, this method is used to relieve the patient of pain not only during surgery, but also in the postoperative period.
Principle of operation
Peridural and epidural anesthesia is a regional anesthetic, 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 dural couplings fall into the subarachnoid space. As a result, pulses passing along the radicular nerves to the spinal cord are blocked.
After all, the drug is introduced in the immediate vicinity of the trunk with nerve cells. Namely, they are responsible for the appearance of pain in different parts of the body and carrying them to the brain.
Depending on the site of administration of the drug, disabling of motor activity and sensitivity in certain areas of the body is possible. Most often, peridural anesthesia is used to "cut off" the lower half of the body. For this, it is necessary to introduce an anesthetic into the intervertebral space between T10-T11.To anesthetize the chest area, the drug is injected into the area between T2 and T3, the upper half of the abdomen can be anesthetized by injecting into the vertebral area of T7-T8.The area of the pelvic organs "turns off" after the injection 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. The latter option is used in cases where it is planned to perform thoracic operations( on the chest) or prolonged surgical interventions in the abdominal region. Their combination and use of anesthetics can minimize the need for patients in opioids.
Separately, epidural anesthesia can be used in such situations:
- anesthesia after surgical interventions;
- local anesthesia during childbirth;
- the need for operations on the legs and other parts of the lower half of the body;
- cesarean section.
In some cases only epidural anesthesia is used. It is used when it is necessary to perform operations:
- on the pelvis, thigh, ankle, tibia;
- for the replacement of the hip or knee joints;
- with a fracture of the neck of the thigh;
- for the removal of hernias.
Spinal anesthesia can be used as one of the methods for treating back pain. Often it is done after surgery. It is also used in vascular surgery in cases where it is necessary to intervene in the lower limbs.
Analgesia of childbirth
More and more women use epidural or spinal anesthesia to avoid painful contractions. With the introduction of an anesthetic, pain sensations disappear, but the consciousness remains in full.
Peripheral 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 can anesthetize the whole process of childbirth. This does not affect the fetus in any way.
Despite the fact that labor is a natural physiological process that does not require extraneous interventions, more and more often women insist that they be anesthetized. Although during labor in the body, a shock dose of endorphins is produced. They contribute to natural anesthesia, because these hormones can provide emotional uplift, suppress a sense of fear and pain.
However, the mechanism for producing endorphins depends on the condition and mood of the woman. For example, prolonged labor with severe pain negatively affects both the woman in childbirth and the unborn baby. In addition, a woman may have increased pressure, a breakdown occurs, and a violation of the main muscle - the heart. In such cases, anesthesia is necessary.
But only on a routine basis can epidural anesthesia be performed. Contraindications to its conduct are often enough. But in emergency cases it is not used also because its action does not occur instantaneously. From the time of the introduction of anesthetics and until complete anesthesia may take half an hour.
Nuances of preparation
If possible, the patient is previously 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 can be prescribed. As a rule, doctors use the drugs "Diazepam" or "Chlozepid".In addition, somewhere an hour before the introduction of anesthesia, intramuscular injections of Diazepam or Diprazin are indicated, and Morphine and Atropine or Fentalin can also be prescribed.
Also a mandatory step is the preparation of sterile styling. For its implementation, napkins( large and small) are needed, rubber sterile gloves, gauze balls, needles, syringes, catheters, two tweezers and two glasses for anesthetic solutions. It is also important to prepare everything necessary to enable you to eliminate possible complications. With such anesthesia, it is impossible to exclude the possibility of severe malfunctions in the blood circulation and respiration system.
Preliminary preparation of 2 syringes, one of which should be 5 ml, and the second - 10 ml. Also, the medical staff prepares needles in the amount of 4 pcs., 2 of which are necessary for the anesthesia of the skin area, where the main injection will be done. Another is needed in order to inject an anesthetic and conduct a catheter, and the latter - to take an anesthetic drug in a syringe.
Carrying out anesthesia
Spinal and peridural anesthesia is done to the patient who sits or lies on his side. As a rule, the latter provision is used much more often. In this case, the patient should bend his back as much as possible, pull his hips to his stomach, and press his head to his chest.
The skin in the area of the injection is carefully processed and covered with sterile napkins. This is done in the same way as before the operation. At the planned site of the puncture, the skin is anesthetized. In addition, to facilitate carrying the needle through the skin, it is recommended to make a small puncture with a narrow scalpel.
Specialists identify two methods of how access can be made to the epidural spinal space: the median and the paramedical. At the first, the needle is inserted in the interval between the spiked processes. After passing through the skin and fatty tissue, it rests first in the fatigue, and then in the interstitial ligament. In elderly patients, they can be quenched, which significantly complicates the introduction of the needle.
The lateral, or paramedic method provides that the injection is made into the region of the boundary 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 does not go to puncture the channel in the middle way. It is recommended in patients with obesity and with sclerotized ligaments.
Features of the "epidural"
Before the planned operations, patients with an anesthesiologist decide which specific anesthetic will be used. But many patients want to understand for themselves what epidural and epidural anesthesia are. What is the difference between these methods, it will not work out. After all, these are two names of the same method of anesthesia, in which the anesthetic is fed into the body gradually through the catheter.
The doctor should know the nuances of the puncture. For example, to perform epidural anesthesia, the needle must pass through the yellow ligament. To do this, remove the mandril and attach the syringe, which contains a solution of sodium chloride, so that there is an air bubble. As soon as the needle enters the bundle, the air bubble will look crushed. But it straightens out immediately, as the point goes into the epidural region.
The anesthetist should also remember other methods of checking whether 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 has been checked by the mandrake. Also, ensure that the small amount of saline introduced does not flow back through the needle after the syringe is disconnected. But this is not a complete list of verification methods. The physician must perform a comprehensive diagnosis in order to ensure the correct position of the needle.
Epidural anesthesia requires the use of a catheter. Introduction of it, as a rule, does not present any difficulties. After selection and testing for patency it is advanced through the needle into the epidural space. After this, the needle is gradually removed, and the catheter is fixed, closing the place of its exit with a bactericidal plaster or a sterile dressing.
To minimize possible complications with peridural anesthesia, it is important to choose the correct dose of anesthetic and correctly perform the procedure of puncture. To carry out anesthesia, use purified solutions of anesthetics that do not contain preservatives.
In some cases, for the epidural anesthetic, the "Lidocaine" agent is used. But they also use such drugs as "Ropivacaine", "Bupivacaine".Under the supervision of a highly qualified experienced physician and in the presence of indications to them, medicines related to opiates can be added. It can be such medicines as "Morphine", "Promedol".But the dosage of these funds is minimal. It can not even be compared to the one used for general anesthesia.
With the introduction of an anesthetic into the epidural region, the latter spreads along it in various directions. It passes up, down and into the paravertebral cellulose through the intervertebral lateral orifices. At the same time, finding out what should be the concentration of "Dicain" for peridural anesthesia, it must be remembered that the zone of anesthesia will depend on the amount of solution, intensity of administration and dosage. In addition to the above, the means "Xichain", "Trimekain", "Markain" can also be used. For complete anesthesia can use about 25-30 ml of solutions of these anesthetics. But this amount is considered the maximum.
Despite the fact that one of the safest is considered peridural anesthesia, there are contraindications to it. These include:
- tuberculosis spondylitis;
- pustules on the back;
- traumatic shock;
- organic lesions of the central nervous system;
- complex deformities of the spine, its disease and pathological lesions;
- intestinal obstruction;
- cardiovascular collapse that occurred with peritonitis;
- the general severe condition of the patient;
- decompensation of the heart;
- children's age;
- hypersensitivity to the components of anesthetic;
- exhaustion of the body.
But do not forget that epidural anesthesia is not always painless and without consequences. Contraindications, complications that occur, you need to find out before you go to the operating table.
It should be understood that the technique of performing such anesthesia is complex, therefore the qualification of the doctor is crucial. The most dangerous is the occurrence of a deep collapse after spinal or epidural analgesia. Most often, this condition occurs when the dura mater is damaged. Because of this, a blockade of sympathetic innervation occurs, as a result, the tone of the vessels decreases, and severe hypotension develops. However, this condition can also develop if the anesthesia is properly performed in those cases where a large proportion of the anesthetic is administered, counting on anesthesia of a wide area.
But problems can develop in the postoperative period. These include:
- the onset of an inflammatory purulent process in the canal of the spinal cord( the cause, as a rule, is a violation of the rules of antiseptic);
- headache and discomfort in the back area;
- paresis of the lower extremities, pelvic organs( can develop due to damage to the spine cord roots).
If patients are anesthetized using Morphine, then they should be monitored more closely. After all, sometimes an epidural anesthetic leads to depression of breathing. Contra-indications for use of this method separately do not allocate. But it is worth remembering that the risk of oppression of respiratory function increases with an increase in the dose of morphine.
Features of spinal anesthesia
Despite the similarity, there are significant differences between epidural and spinal anesthesia. For example, the position of the needle after the puncture of the yellow ligament is not so important. As soon as the needle passes through the dura mater, the doctor feels a feeling of needle failure. The catheter at this kind of anesthesia is not established.
When performing a puncture, care should be taken to ensure that the needle does not go too far and does not damage the roots of the spinal cord. Confirm the fact that the point has already entered the subarachnoid space, it is possible if you remove the mandrake. At the same time, the cerebrospinal fluid begins to separate from the needle. If it arrives intermittently or in insufficient quantity, it is necessary to slightly change its position by rotation. After the correct installation of the needle, the introduction of aneliziruyuschih funds. Their dosage is less than with epidural anesthesia.