Anesthesia of normal delivery
Anesthesia includes the following types of anesthesia: regional anesthesia, pudendal block, perineal infiltration and general anesthesia. Typically, opioids and local anesthetics are used. These drugs penetrate the placenta, so they must be administered in small doses for an hour before delivery in order to avoid toxic effects on the newborn (eg, CNS depression and bradycardia). When using only opioids, adequate analgesia is not provided, so they are used in conjunction with anesthetics. Regional anesthesia - a lumbar epidural injection of a local anesthetic is performed. Epidural anesthesia is increasingly being used for delivery, including cesarean delivery. This type of anesthesia essentially replaced the pudendal and paracervical blockades. For epidural injection, local anesthetics (eg, bupivacaine) are used that have a longer duration of action and a slower onset of action than drugs used for pudendal anesthesia (eg, lidocaine). Other forms of regional anesthesia are caudal injection (into the sacral canal), which is rarely used, and spinal injection (into the paraspinal subarachnoid space). Spinal anesthesia can be performed with caesarean section, but less often it is used for vaginal delivery, because it has a short action (it is undesirable during labor); there is a small risk of a headache in the postoperative period.
When using spinal anesthesia, patients should be under constant supervision, vital signs need to be monitored every 5 minutes to identify and treat possible hypotension.
Pudendal anesthesia is rarely used because of widespread epidural analgesia. Pudendal anesthesia is the local administration of an anesthetic through the vaginal wall in such a way that the anesthetic envelops the pudendal nerve. With this anesthetic, low areas of the vagina, perineum and lower third of the vulva are anesthetized; the upper parts of the vulva are not anesthetized. Pudendal anesthesia is a safe, simple method for uncomplicated spontaneous vaginal births if a woman wants to push herself or if labor progresses and there is no time for epidural anesthesia.
Infiltration of the perineum is usually performed by an anesthetic. This method is not as effective and is used less often as pudendal anesthesia. Paracervical anesthesia is increasingly used in childbirth, because it causes bradycardia in the fetus in more than 15% of cases. Such anesthesia is more often used in abortions in the 1st or in the beginning of the 2nd trimester of pregnancy. The technique consists in introducing 5-10 ml of a 1% solution of lidocaine at positions 3 and 9 hours paracervical; analgesic effect. Short-range.
General anesthesia is performed using inhalational anesthetics (for example, isoflurane) and may cause depression in the mother and fetus; so these drugs are not recommended for normal delivery.
Rarely nitrous oxide 40% with oxygen is used for analgesia during vaginal delivery to such a depth that contact with the patient can be maintained. Thiopental sodium is administered intravenously together with other drugs (for example, succinylcholine, nitrous oxide with oxygen) for general anesthesia with caesarean section; the use of one thiopental sodium does not provide adequate analgesia. Thiopental sodium has a short action. When the drug is used, its concentration in the fetal liver occurs, preventing accumulation in the central nervous system; high doses of the drug may cause a depression in the newborn. Diazepam is sometimes used; However, large doses of the drug administered intravenously to pregnant women before delivery may lead to hypotension, hypothermia, low Apgar scores, worsen metabolic reactions to cold stress, and lead to neurologic depression in the newborn. The use of these drugs is limited, but they are used in the imposition of obstetric forceps, with breech delivery, with twins and with cesarean section.
Benefits during childbirth
A vaginal examination is performed to determine the position and position of the fetal head. With complete smoothing and opening of the cervix, the woman is asked to push with each contraction so that the head passes through the birth canal and appears through the vulva. When approximately 3 or 4 cm of the head appear from the genital cleft of nulliparous (somewhat less in the case of multicircles), methods are used that help to facilitate delivery and reduce the risk of rupture of the perineum. The doctor, if necessary, places the left hand on the head of the child, thus preventing premature extension of the head, and this contributes to its slower progress. At the same time, the doctor places the bent fingers of the right hand on the crotch, covering them with the open genital slit. To advance the head, the doctor can make pressure in the area of the brow, forehead or chin (modified Ritten's reception). The doctor of the obstetrician regulates the progress of the head to produce a slow, safe delivery.
The forceps or vacuum extractor are often used for delivery in the second stage of labor when delivery is prolonged (for example, when the mother is too tired to fully exert pressure). The forceps can also be used in cases where epidural anesthesia relieves attempts. Local anesthesia usually does not affect attempts, so the forceps or vacuum extractor is usually not used if there are no complications. Indications for forceps and vacuum extractor are identical.
Episiotomy is performed only in cases of threatening rupture of the perineum, and if the perineum interferes with normal delivery, it is usually performed in primiparous women. If epidural analgesia is inadequate, local infiltrative anesthesia can be used. Episiotomy prevents excessive stretching and possible rupture of perineal tissues, including previous breaks. The cut is easier to repair than the gap. The most typical incision is in the middle line, from the posterior spike in the direction of the rectum. A rupture of this incision is possible with the capture of the sphincter or rectum, but if this is quickly diagnosed, then such a break is successfully restored and undergoes a good healing.
Discontinuities of an episiotomy wound with rectal engorgement can be prevented by keeping the fetal head in a well-bent position, until the occipital tubercle fits the bony arch. Doing an episiotoprotectomy (intentional dissection of the rectum) is not recommended, because there is a high risk of rectovaginal fistula.
Another type of episiotomy is the medial-lateral incision made from the middle of the posterior adhesion at an angle of 45 ° on both sides. This type of episiotomy does not extend to the sphincter or rectum, but dissection causes great pain in the postpartum period and takes more time to heal than in episiotomy along the midline. Thus, for an episiotomy, a midline cut is preferred. However, at the present stage, the use of episiotomy is reduced because of the high risk of rupture of the sphincter or rectum.
After the birth of the head, the baby's body is grasped so that the shoulders are in an anteroposterior position; gentle pressure on the head of the fetus contributes to the location of the front shoulder under the symphysis. If there is an umbilical cord around the neck, the umbilical cord can be pinched and cut. The head gently rises upwards and a rear shoulder appears from the perineum, the rest of the trunk is extracted without difficulty. The nose, mouth and throat are aspirated with a syringe to remove mucus and fluid and facilitate breathing. Two clamps are placed on the umbilical cord, the umbilical cord is dissected, and a plastic clip is placed on the stump. If violations from the fetus or newborn are suspected, the umbilical cord segment is ligated once again so that arterial blood can be sampled for gas examination. Normally, the pH of the arterial blood is 7, 157, 20. The child is placed in a heated cot or on the mother's abdomen for better adaptation.
After the birth of the child, the doctor puts his hand on the abdominal wall in the area of the uterine fundus to reveal its contractions; the placenta is separated during the 1 st or 2 nd abbreviation, often spotting is noted due to the detached placenta. A woman must push to help the birth of the placenta. If it can not exert itself and if there is a significant bleeding, the placenta can be evacuated by pressing the hands on the abdominal wall and when performing a downward pressure on the uterus. This manipulation can be performed only if the uterus is tight and well contracted, because pressure on the flaccid uterus can promote its eversion. If this procedure is not effective, the doctor pushes the abdominal wall in the area of the corners of the uterus far from the placenta; stretches for the umbilical cord are avoided, because it can promote the eversion of the uterus. If the placenta does not separate within 45-60 minutes, then manual separation and allocation of the placenta is carried out; the doctor enters the entire arm into the uterine cavity, separating the placenta, and then extracts it. In such cases it is necessary to suspect a dense attachment of the placenta (placenta accreta).
The placenta should be examined to identify defects, because fragments left in the uterus can cause bleeding or infection. If the placenta is not completely separated, then a manual examination of the uterine cavity is performed. Some obstetricians examine the uterus after each delivery. However, this is not recommended in everyday practice. Immediately after allocation of the placenta, an oxytocic agent (oxytocin 10 ED intramuscularly or as an infusion of 20 U / 1000 ml of saline at a rate of 125 ml / h) is assigned. This can improve the uterine contractility. Oxytocin can not be used intravenously bolus, because heart arrhythmia may develop.
It is necessary to examine the birth canal in order to identify ruptures of the cervix, existing gaps, an episiotomy wound is sutured. If the mother and the baby are healthy, then they can be together. Many mothers want breastfeeding to begin soon after delivery, and this should be encouraged. Mother, child and father should stay together in a warm, separate ward for an hour or more. After this, the child can be placed in a nursery or left with his mother depending on her desire. Within 1 hour after birth, the mother should be under close supervision, which includes monitoring the contractions of the uterus, checking the amount of bloody discharge from the vagina, measuring blood pressure. The time from birth of the placenta to 4 hours postpartum period is called the 4th stage of childbirth; most complications, especially bleeding, occur at this time, and therefore careful monitoring of the patient is necessary.