Pain relief for childbirth

Since ancient times, people have perceived pain during childbirth as evil and attributed it to punishment coming from supernatural forces. To appease these forces, amulets were used or special rituals were performed. Already in the Middle Ages, they tried to use decoctions of herbs, poppy heads or alcohol to relieve pain during childbirth.

However, the use of these drinks brought only minor relief, while being accompanied by serious adverse events, primarily drowsiness. In 1847, English professor Simpson was the first to use ether anesthesia to relieve pain during childbirth.

Physiological basis of pain during childbirth. Contractions are usually accompanied by pain of varying severity. Many factors influence pain during childbirth, its intensity; truly painless childbirth is rare.

Pain during contractions is caused by:

Dilatation of the cervix.
Contraction of the uterus and tension of the uterine ligaments
Irritation of the peritoneum, the inner surface of the sacrum due to mechanical compression of this area during the passage of the fetus.
Resistance of the pelvic floor muscles.
Accumulation of tissue metabolism products formed during prolonged contraction of the uterus and temporary disruption of the blood supply to the uterus.

The strength of the pain sensation depends on the individual characteristics of the threshold of pain sensitivity, the emotional state of the woman and her attitude towards the birth of the child. It is important not to be afraid of childbirth and labor pain. Nature took care of providing the woman with the painkillers she needed for childbirth. Among the hormones produced during childbirth, a woman’s body releases a large amount of hormones of joy and pleasure - endorphins. These hormones help a woman relax, relieve pain, and give a feeling of emotional uplift. However, the mechanism for producing these hormones is very fragile. If a woman experiences fear during childbirth, then the production of endorphins is reflexively suppressed and a significant amount of adrenaline (a stress hormone produced in the adrenal glands) is released into the blood. In response to the release of adrenaline, convulsive muscle tension occurs (as an adaptive form of response to fear), which leads to compression of muscle vessels and disruption of blood supply to the muscles. Poor blood supply and muscle tension irritate the uterine receptors, which we feel as pain.

The influence of pain on the course of labor.

There is a complex system of receptors in the uterus. There is a relationship between pain stimulation of the uterine receptors and the accumulation of the labor hormone (oxytocin) in the pituitary gland. Evidence has been established of the reflex effects of various painful stimuli on the motor function of the uterus.

The sensations during childbirth largely depend on the woman’s mental state. If a woman in labor concentrates all her attention only on pain, homeostatic mechanisms may be disrupted and normal labor may be disrupted. Pain, fear and anxiety during childbirth stimulate that part of the nerve fibers that irritate the circular fibers of the uterine muscle, thereby resisting the pushing forces of the longitudinal fibers of the uterus and disrupting the dilation of the cervix. Two powerful muscles begin to oppose each other, this puts the muscles of the uterus under enormous tension. The tension is of medium level and is perceived as pain. Overexertion causes disruption of the baby's blood supply through the placenta. If this phenomenon is short-term, then the condition of the fetus does not suffer, since its life support requires much less oxygen saturation in the blood than for an adult. But if this situation persists for a long time, then due to the lack of oxygen, irreversible damage to the tissues and organs of the fetus may occur, primarily to its brain, as the organ most dependent on oxygen.

The main task of labor pain relief is to try to break this vicious circle and not to overstress the uterine muscles. Many women prepared for childbirth manage to cope with this task on their own, without resorting to medication, due to psychological stability and various psychotherapeutic techniques (relaxation, breathing, massage, water procedures). Other women simply need appropriate medical care to reduce the feeling of pain or dull the nervous system's response to pain. If this is not done in time, then overstressing the uterine muscle can lead to negative consequences for the mother and fetus.

Medications used for pain relief during labor must meet the following requirements:

Have a fairly strong and fast-onset analgesic effect.
Suppress negative emotions and feelings of fear, without disturbing the consciousness of the woman in labor for a long period.
Do not have a negative effect on the body of the mother and fetus, weakly penetrate the placenta and into the fetal brain.
Do not have a negative impact on labor, the woman’s ability to participate in childbirth and the course of the postpartum period.
Do not cause drug addiction with the required course of taking the drug.
Be available for use in any obstetric institution.

The following groups of medications are used to relieve labor pain:

1. Antispasmodics are medicinal substances that reduce the tone and contractile activity of smooth muscles and blood vessels. Back in 1923, Academician A.P. Nikolaev proposed using an antispasmodic for pain relief during childbirth. The following drugs are usually used: DROTAVERINE (NO-SPA), PAPAVERINE, BUSKOPAN. The prescription of antispasmodics is indicated:

women in labor who have not undergone sufficient psychoprophylactic training, who show signs of weakness, imbalance of the nervous system, too young and elderly women. In such cases, antispasmodics are used at the beginning of the active phase of the first stage of labor (at 2-3 cm of cervical dilatation) to prevent labor pain and only partly to eliminate it. It is important to wait for regular, steady contractions, otherwise this labor process may be delayed.
for women in labor, as an independent painkiller for already developed pain, or in combination with other drugs, when the cervix is dilated by 4 cm or more.

When labor has developed, antispasmodics do not affect the strength and frequency of contractions and do not interfere with the consciousness of the woman in labor and her ability to act. Antispasmodics are good at helping to cope with the dilatation of the cervix, relieve spasm of smooth muscles, and reduce the duration of the first stage of labor. They do not have a negative effect on the fetus. Side effects include a drop in blood pressure, nausea, dizziness, and weakness. However, these drugs do not have a pronounced analgesic effect.

2. Non-narcotic analgesics: ANALGIN, TRAMAL, TRAMADOL. The use of drugs in this group, despite the good analgesic effect, during childbirth has some limitations.

In particular, analgin, when prescribed at the very beginning of labor, can weaken uterine contractions and lead to the development of weakness of labor. This is due to the fact that analgin suppresses the production of prostaglandins, which accumulate in the wall of the uterus in order to ensure proper functioning of the uterine muscles during childbirth. At the same time, when labor is pronounced, analgin does not affect uterine contractility. In addition, analgin affects blood clotting, which can increase blood loss during childbirth. And the use of a combination of analgesics with antispasmodics shortens the duration of the first stage of labor. Contraindications for the use of analgin during childbirth are impaired renal or liver function, blood diseases, and bronchial asthma.

Tramadol, in addition to being an analgesic, has a sedative effect, which is useful when there is a pronounced emotional component of labor pain. However, the sedative effect of tramadol allows it to be classified as intermediate between analgesics and narcotics. As a rule, respiratory depression in a woman in labor does not occur when using tramadol; it rarely causes short-term dizziness, blurred vision, impaired perception, nausea, vomiting and itching. The use of these drugs for late toxicosis of pregnancy (preeclampsia) is prohibited. However, the use of these drugs is limited, since with repeated administration they affect the nervous system of the fetus, slow down the breathing of the newborn, and disrupt his heart rhythm. Premature newborns are especially sensitive to these drugs.

3. Sedatives - sedatives that relieve irritability, nervousness, and stress. These include DIAZEPAM, HEXENAL, THIOPENTAL, DROPERIDOL Hexenal and thiopental are used during childbirth as components of drug pain relief to relieve agitation, as well as to reduce nausea and vomiting. Side effects of these drugs include hypotension and respiratory depression. They quickly penetrate the placental barrier, but at low doses do not cause significant depression in mature, full-term newborns. These drugs are rarely prescribed during childbirth. The main indication for their use is to obtain a rapid sedative and anticonvulsant effect in pregnant women with severe forms of gestosis.

Diazepam does not have an analgesic effect, so it is prescribed in combination with narcotic or non-narcotic analgesics. Diazepam is able to accelerate the dilatation of the cervix and helps relieve anxiety in a number of women in labor. However, it easily penetrates into the blood of the fetus, and therefore causes breathing problems, a decrease in blood pressure and body temperature, and sometimes signs of neurological depression in newborns.

Droperidol causes a state of neurolepsy (calmness, indifference and aloofness) and has a strong antiemetic effect. It has become widespread in obstetric practice. However, one should be aware of the side effects of droperidol: it causes incoordination and weakness in the mother, respiratory depression and a drop in blood pressure in the newborn. For high blood pressure in a woman in labor, droperidol is combined with analgesics.

4. Narcotic analgesics: PROMEDOL, FENTANYL, OMNOPON, GHB

The mechanism of action of these drugs is based on interaction with opiate receptors. They are considered safe for mother and baby. They have a calming effect, relaxing, maintaining consciousness. They have an analgesic, antispasmodic effect, promote dilation of the cervix, and help correct uncoordinated uterine contractions.

However, all narcotic drugs have a number of disadvantages, the main of which is that in high doses they depress breathing and cause drug dependence, a state of stupor, nausea, vomiting, constipation, depression, and low blood pressure. The drugs easily penetrate the placenta, and the more time passes from the moment of administration of the drug, the higher its concentration in the blood of the newborn. The maximum concentration of promedol in the blood plasma of a newborn was observed 2-3 hours after its administration to the mother. If birth occurs at this time, the drug causes temporary respiratory depression in the baby.

Sodium hydroxybutyrate (GHB) is used when it is necessary to provide rest to a woman in labor. As a rule, when the drug is administered, sleep occurs within 10-15 minutes and lasts 2-5 hours.

5. Inhalation anesthesia for childbirth NITRIC OXIDE, TRILEN, PENTRAN

These methods of pain relief have been used for a very long time. Ether is not currently used for pain relief in labor, as it significantly weakens labor, can increase blood pressure, and have an adverse effect on the fetus.

Inhalation analgesia of labor by inhaling painkillers is still widely used in obstetric practice. Inhalation anesthetics are used during the active phase of labor when the cervix is dilated by at least 3-4 cm and in the presence of severe painful contractions.

Nitrous oxide is the main inhalational agent used for both obstetric pain relief and labor pain relief. The advantage of nitrous oxide is its safety for the mother and fetus, the rapid onset of action and its rapid completion, as well as the absence of a negative effect on contractile activity and a strong odor. Nitrous oxide is given through a special apparatus using a mask. The woman in labor is introduced to the technique of using a mask and she herself applies the mask and inhales nitrous oxide and oxygen as needed. When inhaling it, a woman feels dizzy or nauseous. The effect of the gas appears after half a minute, so at the beginning of the contraction you need to take several deep breaths

Trilene is a clear liquid with a pungent odor. It has an analgesic effect even in small concentrations and while maintaining consciousness. Does not suppress labor. This is a well-administered, fast-acting drug - after stopping inhalation it quickly ceases to have an effect on the body. The disadvantage is the unpleasant smell.

6. Epidural anesthesia during childbirth and caesarean section

Performing epidural analgesia involves blocking pain impulses from the uterus along the nerve pathways entering the spinal cord at a certain level by injecting a local anesthetic into the space around the spinal cord membrane.

Performed by an experienced anesthesiologist. The time to start epidural analgesia is determined by the obstetrician and anesthesiologist depending on the needs of the mother and baby during labor. It is usually carried out when regular labor is established and the cervix is dilated by at least 3-4 cm.

A lumbar epidural is performed in the lower back with the woman in labor sitting or lying on her side. After treating the skin in the lumbar spine, the anesthesiologist makes a puncture between the vertebrae and enters the epidural space of the spine. First, a test dose of anesthetic is administered, then, if there are no side effects, a catheter is installed and the required dose is administered. Sometimes the catheter may touch a nerve, causing a shooting sensation in the leg. The catheter is attached to the back; if it is necessary to increase the dose, subsequent injections will no longer require repeated puncture, but are performed through the catheter.

Pain relief usually develops 10-20 minutes after the epidural insertion and can be continued until the end of labor and is usually very effective. Epidural anesthesia is safe for mother and baby. Side effects include decreased blood pressure, back pain, weakness in the legs, and headaches. More severe complications include a toxic reaction to local anesthetics, respiratory arrest, and neurological disorders. They are extremely rare.

Sometimes the use of epidural anesthesia leads to a weakening of labor. At the same time, the woman cannot push effectively, and thus the percentage of surgical interventions (obstetric forceps) increases.

Contraindications to the use of epidural anesthesia are: blood clotting disorders, infected wounds, scars and tumors at the puncture site, bleeding, diseases of the nervous system and spine.

Epidural anesthesia can be used with a reasonable degree of safety for caesarean section. If an epidural catheter is already installed during labor and a caesarean section becomes necessary, it is usually sufficient to administer an additional dose of anesthetic through the same catheter. A higher concentration of the drug allows you to cause a feeling of “numbness” in the abdominal cavity, sufficient for surgery

7. General anesthesia.

Indications for the use of general anesthesia during childbirth are emergency situations, such as a sharp deterioration in the child’s condition and maternal bleeding. This anesthesia can be started immediately and causes rapid loss of consciousness, allowing immediate caesarean section. In these cases, general anesthesia is relatively safe for the child.

The use of any painkillers during childbirth is carried out only by obstetrician-gynecologists and anesthesiologists-resuscitators. Nurses, anesthetists and midwives follow doctors' orders, monitor the mother's condition and note possible side effects that require changes in treatment.