Epidural anesthesia for childbirth

Epidural anesthesia for childbirth

24.05.2022 0 By admin

epidural anesthesia

Epidural anesthesia is a method of regional anesthesia, which consists in the introduction of an anesthetic drug into the epidural space of the spine. This method of analgesia is increasingly used as the main method during childbirth, in gynecology, urology, proctology, during surgical interventions on the lower extremities, pelvic organs. Practicing anesthesiologists, gynecologists and surgeons often use the outdated term “epidural anesthesia”, but the essence is the same, they are synonyms.

Operating principle

The spinal cord is surrounded by several membranes. The innervation of skeletal muscles and internal organs is carried out by nerve fibers that originate in the nerve roots extending from the spinal cord. The anterior roots are responsible for the contractility of skeletal muscles, the posterior roots are responsible for the functioning and sensitivity of internal organs, including pain. The roots pass through the hard shell through the epidural space, which is surrounded by dense adipose tissue. It is in the epidural (epidural) space that an analgesic is injected, temporarily suspending the functioning of the nerve roots, that is, depriving them of pain sensitivity.

Technique

The patient sits on the edge of the couch, table or lies on her side, arching her back as much as possible to separate the edges of the vertebrae and increase the intervertebral fissure through which the catheter will be inserted.
After antibacterial treatment of the skin surface, the anesthesiologist or surgeon performs anesthesia of the skin and subcutaneous fat by injecting the anesthetic with a separate needle. Sometimes skin anesthesia is not performed, since, according to subjective sensations, an injection for local anesthesia and a puncture of the epidural space are perceived by patients in the same way.

At the level of the lower back between the spinous processes, the doctor makes a puncture of the epidural space, not reaching the spinal cord. By pulling the syringe plunger slightly, the doctor controls that the needle does not enter the blood vessel (blood enters the syringe). A thin catheter is inserted through the needle. The needle is removed. The catheter is attached to the skin with a band-aid (rarely with a surgical suture) to administer drugs.
A trial small dose of the drug is administered. In the absence of adverse reactions, the main dose of anesthetic is administered. In the future, the introduction of the drug is carried out with a 30-minute interval as pain occurs or at the discretion of the doctor.

After a few minutes, there is a feeling of weakness, numbness and warmth in the legs, the contractions cease to be painful. If before this labor activity was unbalanced, contractions of the muscles of the uterus were uneven, then after the introduction of an anesthetic, labor activity weakens somewhat, but becomes balanced. At the same time, the opening time of the cervix is reduced.

If blood pressure is elevated, which is often a concomitant complication of labor, after the administration of an anesthetic, it usually normalizes by relieving spasm of small peripheral vessels. With initially low pressure, intravenous administration of an increased volume of fluid and drugs that increase it is necessary.

Maintaining normal pressure is provided by the volume of circulating blood and the tone of the vascular walls. Since a decrease in vascular tone is inevitable during epidural anesthesia, the only option to maintain the norm is the introduction of an additional volume of fluid.

At the end of the first stage of labor, the administration of the anesthetic is usually stopped. This ensures normal attempts and active childbirth. In some countries, anesthesia continues in both the first and second periods, but in Russia the practice of anesthesia is only the first period. With continued administration of the anesthetic in the second period, it lengthens, which may require surgical intervention.

If ruptures occur or a perineal incision is necessary, sutures are applied after additional injection of an anesthetic into the epidural space. After childbirth, the woman is under the supervision of an anesthesiologist for at least two hours. Monitoring of pressure, cardiac activity, the process of restoring the sensitivity of the lower extremities is carried out. Before transfer to the postpartum ward, the catheter is removed.

During childbirth, the woman is fully conscious and controls the entire process. In some cases, when the consciousness of a woman can interfere with the normal process (mental illness, asthma, nervous disorders), or at the request of the woman in labor, sleeping pills or other sensitizing drugs are administered after the introduction of the catheter. In this case, artificial ventilation of the lungs, unlike general anesthesia, is not required.

Drugs introduced into the epidural space enter the bloodstream in very small concentrations and after a long time, since the process of absorption between the membranes of the spinal cord is slowed down. The newborn practically does not receive additional chemicals, or their dose is so negligible that it cannot have any effect on his health.

Medications

epidural anesthesia for childbirth

For epidural anesthesia, local anesthetics are used – lidocaine, bapivacaine and others. Often, to enhance the analgesic effect, medical opiates are added to the anesthesia solution – morphine, promedol, fentanyl. Doses of opiates are several times less than with intramuscular or intravenous administration, but the analgesic effect is more pronounced and prolonged. Opiates do not have a sensitizing (intoxicating) effect, since their dose is insignificant, and the process of absorption of substances from the epidural space is slowed down. Side effects observed in the treatment of opiates (nausea, vomiting, dizziness, respiratory depression) are not observed, since pain relief occurs at the level of the spinal (regional) and not the central nervous system.

If the doctor decides to add additional drugs (clophelin, ketamine, physostigmine, etc.) to the solution for epidural anesthesia, then their dose is also several times less than with conventional parenteral (intravenous, intramuscular) administration.

In natural childbirth, anesthetics are usually used for a short period of effectiveness (lidocaine), for caesarean section and other operations – for a long period (bapivacaine). Modern drugs are harmless to both the mother and the newborn, allergic reactions are rare.

Contraindications

As with any invasive intervention, a number of contraindications have been identified for epidural anesthesia.

  • hypersensitivity, allergy to drugs;
  • blood clotting disorders, low platelet count;
  • chronic cardiovascular diseases;
  • the risk of bleeding;
  • scoliosis, post-traumatic or other curvature of the spine;
  • herniated discs;
  • osteochondrosis of the lumbar;
  • skin inflammatory diseases in the puncture area.

Indications

Where is epidural anesthesia given?

The main indication for epidural anesthesia is the desire of the woman herself. Childbirth is very painful and accompanied by suffering, anesthesia relieves the patient of unnecessary pain, childbirth is painless and most often without complications.

In some cases, epidural anesthesia is prescribed not only at the request of the patient herself, but also for medical reasons.

  • premature birth. During anesthesia, the entire lower body relaxes, the uterus receives sufficient blood supply, the condition of the fetus improves, labor activity is facilitated.
  • The cervix does not open during intense contractions. Anesthesia allows you to eliminate hypertonicity (tension, spasm) of the muscles of the cervix and normalize the rhythm of contractions.
  • Arterial hypertension.
  • Low pain threshold.
  • Prolonged childbirth.
  • High risk of changing the tactics of childbirth (emergency caesarean section).

Complications

Negative effects during and after epidural anesthesia are observed infrequently, but the risk of their development must be considered:

  • Headache – most often occurs if, during the installation of the catheter, the needle (or the catheter itself) penetrated a little further and cerebrospinal fluid entered the epidural cavity. Headaches after epidural anesthesia occur during the first day after manipulation, subside or intensify with a change in body position. No special measures are required. The pain usually goes away on its own after a few days.
  • Sometimes the back hurts after epidural anesthesia and childbirth at the site of the catheter. The pain is of minor intensity and does not cause anxiety. They go away on their own within a few days.
  • Drop in blood pressure – the introduction of an additional volume of fluid.
  • Allergies to injected drugs are common measures aimed at combating anaphylactic shock.

Is epidural anesthesia worth it?

Despite the recommendations of doctors and obstetricians, the choice to do epidural anesthesia or refuse in the end still remains with the woman.

Everyone has their own level of pain sensitivity. As a result of pain in a woman, pressure may increase, blood sugar may rise, an exacerbation of neuropsychiatric diseases, and problems with cardiac activity may occur. And why endure pain if you can avoid it? Childbirth after epidural anesthesia is easier.

On the other hand, complications do occur, albeit extremely rarely. Some women strive to do everything as naturally as possible, “closer to nature”. Someone does not even apply to the maternity hospital, but gives birth at home in the bathroom. Every expectant mother should understand that not only her own health is at stake, but also the well-being of the future little person. Painful childbirth, complications can not only lead to the suffering of the mother herself, but also affect the condition of the baby.

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