Anesthesia in Caesarean section

Anesthesia with caesarean section may be different. An anesthesiologist should be remembered and told to the obstetrician and neonatologist if more than 8 minutes passes from the skin incision to the extraction of the fetus and more than 3 minutes from the incision of the uterus before it is removed. Regardless of the technique, there is a high risk of intrauterine hypoxia and acidosis in the fetus / newborn.

Advantages of RAA:

• minimal risk of aspiration of gastric contents into the trachea;
• the risk of failure with intubation of the trachea appears only in the development of complications;
• presence at birth, early contact with the child;
• there is no risk of an unforeseen exit from the state of anesthesia.

Disadvantages of RAA:

• possible a complete absence or inadequate effect;
• unexpectedly high or complete blockade;
• headache after spinal puncture;
• neurological complications;
• toxicity of local anesthetics during epidural administration.

Advantages of endotracheal anesthesia in cesarean section:

• rapid offensive;
• allows quick access to all parts of the body for surgical and anesthetic interventions;
• allows to control gas exchange and hemodynamics;
• quickly cures convulsions.

Disadvantages of endotracheal anesthesia in cesarean section:

• risk of unsuccessful intubation of the trachea;
• risk of aspiration of stomach contents into the trachea;
• risk of intraoperative recovery of consciousness;
• risk of CNS depression in a newborn;
• it is possible to develop abnormal reactions to the drugs used.

Stacking the pregnant on the table is done with a roller under the right / left buttock. The risk of developing arterial hypotension with the application of regional methods is higher than when using them for analgesia in childbirth. When choosing these methods, it is necessary to introduce 1200-1500 ml of crystalloids and / or starches proactively and to prepare a solution of ephedrine:

Hydroxyethyl starch, 6% rr, IV

500 ml, 

+

Crystalloids in / in 800 ml, or Crystalloids iv in 1200-1500 ml.

[1], [2], [3], [4]

Epidural anesthesia in cesarean section

With a planned cesarean section is a method of choice. They use:

Bupivacaine, 0.5% rr, epidural 15-25 ml, or lidocaine, 1.5-2% rr, epidurally 15-25 ml. If the administration of the test dose did not reveal an incorrect position of the catheter, 5 ml of MA is administered fractionally to a total dose of 15-25 ml. In pregnant women with sympathicotonia, the addition of MA clonidine to the solution enhances and prolongs anesthesia with caesarean section, without adversely affecting the fetus and the newborn:

Clonidine epidurally 100-200 mkg, according to indications (often fractional). When pain occurs, re-injected MA fractional 5 ml before the onset of the effect. Epidural administration of morphine at the end of the operation provides adequate postoperative analgesia within 24 hours. Alternative is a permanent epidural infusion of fentanyl or sufentanil:

Morphine epidurally 3-5 mg, or Sufentanil epidurally 10-20 mcg / h, the duration of administration is determined by clinical expediency or Fentanyl epidurally 50-75 mkg / h, the frequency of administration is determined by clinical feasibility.

[5], [6], [7], [8]

Spinal anesthesia for caesarean section

Fast and reliable anesthesia with caesarean section in the absence of contraindications. They use:

Bupivacaine, 0.5% r-p (hyperbaric rr), subarachnoidally 7-15 mg, or lidocaine, 5% r-p (hyperbaric rr), subarachnoidally 60-90 mg. The use of thin (22 G and thinner) pencil-type spinal needles (Whitecra or Sprott) reduces the risk of post-puncture headache. Even at a blockade level of Th4, a pregnant woman may experience discomfort during traction of the uterus. The addition of low-dose opioids to MA (fentanyl 10-25 μg) reduces the intensity of these sensations without adversely affecting the condition of the newborn. There are data on the use of clonidine (50-100 μg) in combination with bu-pivacaine in CA.

Long spinal anesthesia with caesarean section is suitable for unintentional puncture of the dura mater during the catheterization of the epidural space. The catheter is held at 2-2.5 cm in the subarachnoid space and fixed, after which it can be used for infusion of drugs.

General anesthesia for caesarean section

The method of choice for planned and emergency cesarean section, when RAA is contraindicated, is expected or has already occurred a significant loss of blood (placental abruption and presentation, rupture of the uterus, etc.). Premedication:

Diphenhydramine in / m 0.14 mg / kg (in an emergency - in / in before induction) for 30-40 minutes before the scheduled operation

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Atropine IV / 0.01 mg / kg, on the operating table or iodide iodide at 0.01 mg / kg, on the operating table

+

Ketoprofen IV 100 mg, 30-40 minutes before the scheduled operation, or Ketorolac IV 0.5 mg / kg, 30-40 minutes before the scheduled operation. In a planned situation appoint: Ranitidine inside 150 mg, 6-12 hours and 1 to 3 hours before induction, or cimetidine inside 400 mg or IM 300 mg, for 6-12 hours and 1 to 3 hours before induction

+

Metoclopramide iv 10 mg, 1.5 hours before induction

+

Sodium citrate, 0, 3M p-p, inward 30 ml, 30 minutes before induction. The most effective use of omeprazole:

Omeprazole inside 40 mg, at night and in the morning on the day of surgery. In an emergency situation, appoint:

Ranitidine IV 50 mg, or Cimetidine IV 200 mg,

Metoclopramide iv 10 mg,

+

Sodium citrate, 0.3 M rp, inward 30 ml, 30 minutes before induction. An alternative is the appointment of omeprazole:

Omeprazole IV 40 mg.

There is no consensus on the emptying of the stomach. The author is impressed by the following procedure

If from the moment of food intake 3-4 hours pass and the risk of difficult intubation of the trachea is low, the above prevention is enough. If less than 3-4 hours have passed from the time of ingestion and the risk of difficult intubation is high, it is necessary to compare the significance of the effects of hyperkatecholamineemia and the "start-up" of a vomiting reflex in response to the introduction of a gastric probe with the risk of aspiration of gastric contents into the trachea if it is not administered and its own skills intubation of the trachea in pregnant women. The conclusion will suggest the optimal solution to the problem. As a means of removing gastric contents, the nasogastric tube is unreliable (but if used, the diameter should be maximal), its presence in the stomach during induction increases the risk of regurgitation, and therefore the probe should be better removed before induction. Do not assume that the stomach is completely emptied by vomiting and / or insertion of the probe, so the above prevention should always be done.

Then you need:

• insert a large diameter catheter (1,7 mm) into the vein (peripheral and / or central);
• establish a catheter in the bladder (the obstetrician decides if there is no direct indication);
• conduct standard monitoring;
• lay the pregnant woman on her back and move the uterus to the left / right by placing the roller under the right / left buttock;
• Pre-oxygenation of 100% oxygen for 3 minutes (in an emergency situation, ventilation is only begun after intubation of the trachea). If the anesthesiologist prepares for difficult intubation of the trachea (assessment of the difficulty of SR Mallampati), the risk of failure during its implementation is significantly reduced: the conscious algorithm allows to significantly shorten the time for finding solutions, and the availability (availability) of the necessary equipment is the time for their implementation. The life of a woman in childbirth takes precedence over delivery, but one should also remember the high responsibility for the successful birth of a new life.

The necessary equipment includes (the list should be regularly reviewed):

• second laryngoscope;
• a set of endotracheal tubes;
• combined tube with obturator of the esophagus;
• a set of oral ducts; o nasal airways;
• Laryngeal masks (size 3 and 4) for temporary maintenance of adequate ventilation in a critical situation;
• set for conicotomy;
• set for dilatational tracheostomy; about fibrobronhoscope;
• A high professional level of application of all listed on the conscious algorithm. The described preoperative preparation is suitable for all pregnant women, whose delivery method is the cesarean section, In case of failure in the implementation of regional methods, an alternative would be endotracheal anesthesia in cesarean section, but without time for preparation.

Induction anesthesia with caesarean section

Ketamine iv 1 - 1.2 mg / kg, (Scheme 1) or gecobarbital iv 4-5 mg / kg, once (Scheme 2) or Ketamine IV 0.5-0.6 mg / kg,

+

Heckobarbital iv / 2 mg / kg, (Scheme 3) or Clonidine IV at 2-3.5 μg / kg, 

+

Ketamine IV 0.8-1 mg / kg, (Scheme 4) or Clonidine IV at 2-3.5 μg / kg,

+

Heckobarbital iv 3-3.5 mg / kg, once (Scheme 5).

If there are no contraindications, induced anesthesia with caesarean section is performed in / in ketamine or hexobarbital (or a combination thereof, respectively). In bleeding, there is no alternative to ketamine, but it should be remembered that sometimes in pregnant women with severe hemorrhagic shock, circulatory insufficiency, the drug may reduce the contractile ability of the myocardium due to sympathetic hyperstimulation.

In pregnant women with initial sympathicotonia and / or gestosis, depending on the baseline level of AD, schemes 4 or 5 with additional administration of tranexamic acid are used, which can be included in schemes 1-3 if a traumatic operation with large blood loss is assumed:

Tranexamic acid iv 8-9 mg / kg, once.

Muscle relaxation:

Suxamethonium chloride IV iv 1.5 mg / kg, once.

After induction, anesthesia in cesarean section is carried out by suxamethonium chloride (it is desirable that the total dose before fetal extraction does not exceed 180-200 mg), intubate the trachea using Sellic's method and switch to mechanical ventilation. The only drug that provides rapid muscle relaxation is suxamethonium chloride. Suxamethonium chloride is poorly soluble in fats, has a high degree of ionization. In this regard, it passes through the placenta in very small quantities. A single injection of 1 mg / kg of the woman giving birth to her mother is safe for the fetus, but large doses or repeated injections with a small interval can affect neuromuscular transmission in the newborn. In addition, if the mother and fetus are homozygous for atypical plasma pseudocholinesterase, then despite the mother's administration of minimal doses of suxamethonium chloride, her concentration in fetal blood may be sufficient to cause severe inhibition of neuromuscular conduction.

In the case of an induction of anesthesia in a cesarean section according to schemes 1, 2 or 3, anesthesia with a caesarean section is performed using:

Dinitrogen oxide with oxygen inhalation (1: 1 or 2: 1). After the extraction of the fetus, enter:

Fentanyl iv 3-4 mcg / kg (0.2-0.3 mg), once, then after 15-20 min I IV iv 1.4 g / kg, single dose

+

Diazepam iv in 0.14-0.2 mg / kg (10-15 mg), once according to the indications

±

Droperidol in / in 0.035-0.07 mg / kg, once.

In the case of induction of anesthesia according to Schemes 4 and 5, anesthesia with caesarean section is performed using:

Dinitrogen oxide with oxygen inhalation (1: 1 or 2: 1). After fetal extraction, Fentanyl is administered iv 1.4-2 .mu.g / kg, once, then 25-30 min / v / 0.7-0.8 mcg / kg, once

+

Diazepam iv in 0,07-0,14 mg / kg, once.

In pregnant women with initial sympathicotonia and / or gestosis, depending on the baseline level of blood pressure, schemes 4 or 5 are applied with additional administration of tranexamic acid in the incision stage, which is also included in schemes 1-3 if the operation is traumatic and may be accompanied by a large blood loss:

Tranexamic acid iv 5-6 mg / kg, once.

Before fetal extraction, the ventilator is continued with dinitrogen oxide and oxygen in a ratio of 1: 1, muscle relaxation is maintained by suxamethonium chloride or by the introduction of short-acting nedepolarizing short-acting muscle relaxants (mitakuriya chloride).

It is necessary to avoid hyperventilation due to its negative effect on uterine blood flow. After the extraction of the fetus, an antibiotic is administered (prophylaxis of intraoperative infection is coordinated with the obstetrician). After separation and removal of the placenta - metilergometrin (in the absence of contraindications) and / or switch to oxytocin infusion (check with the obstetrician): Methylergometrin IV, once or Oksitotsin iv 5-10 ED, once, then capillary 5-10 ED.

With hypotension of the uterus additionally injected with calcium preparations:

Calcium gluconate, 10% rr, IV 5-10 ml, once or calcium chloride, 10% rr, iv 5-10 ml, once.

After clamping the umbilical cord is continued by mechanical ventilation with dinitrogen oxide and oxygen in a ratio of 1: 1 or 2: 1 and go on to NLA or ataralgesia. Enter fentanyl and diazepam or midazolam in an equivalent dose.

It is necessary to remember the presence of an enterohepatic cycle in diazepam, which provokes the occurrence of a resentation coinciding with the appearance of active metabolites. Within a few hours, such a rebound phenomenon can cause not only resentation, but also respiratory failure. Repeated fentanyl is administered after 15-20 minutes at a dose of -1.4 μg / kg (0.1 mg), stopping the introduction 30-40 minutes before the end of the operation (before immersion of the uterus in the abdominal cavity). If there are indications, use droperidol. Pregnant with initial sympathicotonia and / or gestosis (see algorithm) shows the inclusion in the anesthesia scheme of central alpha-adrenostimulating drugs (clonidine and its analogues - dexamethetomidine, etc.) and / or protease inhibitors (tranexamic acid). Anesthesia with caesarean section is performed using clonidine (Schemes 4 and 5) is identical to the above. Clonidine is injected immediately after admission of the pregnant woman to the operating room (a thorough evaluation of the vollemic status is necessary, if necessary, correction; the drug in this situation has only an antihypertensive effect, and with the preservation of autoregulation of the systemic blood flow).

Within 5 minutes, assess the parameters of blood pressure, heart rate, level of consciousness, based on HR data determine and enter the necessary dose of atropine (metocinium iodide). Due to the analgesic, sedative and vegetostabilizing properties of clonidine, the sensitivity of the body to anesthetics, anxiolytics, analgesics, neuroleptics and muscle relaxants, whose doses are reduced by 1/3 compared to standard ones, increases. Induction is carried out with ketamine or hexenal.

After fetal extraction, fentanyl and diazepam (or midazalam) are administered. Fentanyl is used repeatedly after 25-30 min, depending on the traumatism and duration of the operation.

In comparison with the standard anesthesia with caesarean section provides more stable hemodynamic parameters at the intra- and postoperative stages: after restoration of consciousness, there are no pain sensations, muscle trembling, microcirculatory disturbances.

Anesthesia with caesarean section using tranexamic acid is identical to the above. In addition to the above variant, there is another version of the use of tranexamic acid, 7-8 mg / kg before induction, and at the same dose of IV drip every hour of the operation. The use of tranexamic acid makes it possible to reduce the doses of narcotic analgesics, anxiolytics and muscle relaxants, and therefore the frequency of side effects and complications, is accompanied by less bleeding and blood loss (by 20-30%).

In the absence of contraindications in pregnant women with severe sympathicotonia and severe gestosis in cesarean section, the use of combined (endotracheal and regional) anesthesia in a cesarean section in which analgesia and HBT are represented predominantly by a regional technique and the remaining components by endotracheal is called a multicomponent balanced level subcomponents and ways of their introduction by anesthesia.