Lecture of anaesthesia for caesarean section

2021-03-19 12:00 AM

The pregnant uterus pushes the diaphragm to 4cm high at the end of pregnancy, the diameter fore and thoracic increases by 2cm, the thoracic circumference increases by 5 to 7cm.

Physiological changes of pregnant women - related to anaesthesia

Pregnancy makes important changes to the mother's body in order to adapt to the new physiological conditions. These changes are related to hormones, uterine progression and increased metabolic demand.

Respiratory changes

Anatomical changes:

The airway mucosa (especially the larynx) is red due to vasodilation, swelling due to water and salt retention.

A pregnant uterus pushes the diaphragm 4 cm high towards the end of pregnancy. Diameter before - behind chest increased 2cm, breast base increased 5-7cm. Due to fetal development, abdominal breathing decreases and chest breathing increases.

Ventilation changes :

Air circulation increases by 40% by the end of pregnancy.

Sediment volume and exhalation reserves decrease by 15-20% by the end of pregnancy.

The inhalation reserve volume remains constant.

Living capacity and total lung capacity changed very little.

Increased inhalation capacity.

Functional residue capacity is reduced by 15-20%.

The pulmonary elasticity is less likely to change, the chest elasticity is reduced.

Ventilation/perfusion indexes are little changed.

Change of e given guava gas :

Hyperventilation is the main change. Late gestation increases 50%, mainly the volume of circulating air and increases the ventilatory energy (70%) decreases C02- Metabolic demand increases by 14%. Consumption 02 increased 21%.

Alveolar diffusion - capillary unchanged.

Arterial gas: decreased muscle2 so respiratory alkalosis (compensated kidney) pH = 7.40 - 7.45. Pa2 increased moderately (106-108 mmHg) in the first 3 months, decreased slightly or remained high in the last 3 months.

During labour:

Pain increases ventilation. Minute ventilation> 10 liters / min outside the contraction and 231 / min during uterine contraction. Increased ventilation makes PaC02 reduce to 10-15mmHg and H = 7.55 - 7.60 respiratory alkalosis, causing dissociation curve of Hb to the left and constriction of TC-R vasoconstriction causing reduction of 02 pregnancies. When the pain is gone, C02 decreases, and the beginning of the period of a temporary decrease in cervical ventilation decreases 2 in the mother (Pa02 <70mmHg), affecting the fetus.

Prolonged labor leads to maternal metabolic acidosis, lactate accumulation may increase fetal failure in case of deficiency 02.

In relation to anaesthesia:

Difficulty with intubation due to edema, more difficult in women with pre-eclampsia, obesity, trauma or intubation. Due to congestion should be gentle (tube is smaller than usual).

Term gestation reduces functional residue capacity (20%), increases consumption of 02 (21%) reduces reserve 02 easily causes lack of 02 during anaesthesia and intubation, need for 02 100% before anesthesia (inhalation deep 02 100% 4 times).

Due to increased ventilation, increased sensitivity to evaporative anesthetic will speed up the onset of anesthesia. 2. Change in period

Pregnancy has many cardiovascular effects to ensure metabolic needs due to fetal development and preparation for childbirth.

Change of heart rate

Heart rate increases early 10-15 beats/minute.

Full heart size, enlarged heart ball when chest scan.

Circulating volume

Increase in the first 3 months of pregnancy. Late pregnancy increases 35-45%.

Increased plasma volume> 50%.

The number of red blood cells increases by 20% (relative anemia).

Hematocrit decreased.

Hemoglobin (Hb) <llgr / lOOml.

Physiological blood loss lower sugar delivery = 300-500ml, blood loss due to cesarean section 500-700ml. If the loss> lOOOml of blood has symptoms of hypovolemia, it should be treated.


During pregnancy:

Blood pressure:

Maximum blood pressure drops as soon as 7 weeks and then gradually increases until the end of the month. Between 24-28 maximum blood pressure and minimum blood pressure drop (8-15%).

Peripheral vascular resistance decreased by 20% and increased late pregnancy (due to development of uterine circulation - vegetables, vasoconstriction caused by hormones estrogen, progestin, prostaglandin in place.

Pulmonary artery pressure is reduced by 30% by the end of pregnancy.

Cardiac output:

Gradually increasing, increasing by 30-40% in the 8th week to the end of the first 3 months, slightly increasing in the last 3 months until the end of the month.

Lying on your back, cardiac output is reduced by 15% compared to incline.

Cardiac output increases due to systolic ejection volume and increased heart rate.

Regional flow:

Uterine flow from 50ml / min in early pregnancy increases by 500ml / min at full term. Uterine weight 40g before pregnancy increases 1000g near full term.

The uterine muscle receives 20%, the vegetable receives 80% of the uterine blood flow - the vegetable.

Uterine circulation - vegetables have capillary resistance.

Change positions:

In late pregnancy, lying on her back with legs stretched out, blood pressure decreased> 10%.

Symptoms: sweating, nausea, possible consciousness disturbances. Symptoms appear a few minutes after lying on your back. This is inferior compression syndrome, reducing venous blood returning to the heart, reducing heart flow, lowering blood pressure will decrease uterine flow - vegetables cause pregnancy failure.

During labor :

Cardiac flow increases gradually due to pain and stress. Early labor, without pain relief, cardiac flow increases 15-20% between contractions compared to late pregnancy. 45-50% increase when birth registration. Each contraction also increases by 20-30% (due to the penetration of 250-300ml of blood into the mother's circulation) and catecholamine release.

Prophylaxis of host compression syndrome.

Push the uterus to the left: lie on your left side or place a pillow under your right hip, or leave the table tilted 15-20 °, infusion before anaesthesia 500-500ml Ringer lactate.

Lower aortic compression to dilate the cavity vein will decrease the epidural space by 40% (need to reduce 1/3 dose of anaesthetic)

An anaesthesia needle or catheter is inserted out of contraction to avoid perforation of the vein and

The limited rapid absorption of the anaesthetic.

Changes in blood composition

Tangible factors :

Reduced red blood cells, Hb, leukocytosis (7,200-10,300 / ml) increased neutrophils, lymphocytes increased by 10%. The T and B lymphocyte ratios remain unchanged.

Platelets have little change, 7% platelets <150,000mm3 of which 5% <100,000mm3.

C roaring blood :

Increasing tendency - »risk of embolism. Bleeding, blood clotting little changed.

From the 3rd month: Fibrinogen, factors VII, VIII, X, XII increase.

Reducing coagulation inhibitors: antithrombin III, protein s.

Reduced plasminogen activating factor caused by placenta.

At birth: reducing íibrinogen and factor VIII, increasing íibrine degradation products.

Postpartum: hypercoagulation lasts for 4-6 weeks.

other changes :

Blood viscosity decreases until 30 weeks, then increases slightly towards the end of pregnancy. Increased íibrino- gen -> • speed up red blood cell deposition.

Blood protein decreased, mainly albumin decreased by 10%, Y globulin decreased slightly, a1 and a2 as well as 3 globulin increased.

The parallel decrease in osmotic pressure reduces albumin ==> the risk of pulmonary edema, especially the disease with decreased osmotic pressure, increased pulmonary capillary pressure and destroyed coordination capillary.

Changes in digestion

The replacement e guava Main :

Reduced intestinal motility, cholestasis can create stones caused by progesterone.

Pain, anxiety, and morphine slow down stomach emptying.

The lower esophageal sphincter tone decreases, the posture of the stomach opens the center of the aneurysm that will cause reflux (80%) which can cause inflammation of the esophagus.

At term, gastric pressure increases due to increased abdominal pressure (uterus, gynecological posture, Trendelenbourg posture, pressure on the abdomen, etc.).

Increased gastric acidity and volume due to placenta gastrin.

In relation to anesthesia :

Inhalation of gastric contents due to vomiting, reflux.

All pregnant women must be considered to have a full stomach.

To reduce the risk of Mendelson's syndrome requires:

Fasting in labor.

Give medications to reduce stomach acid and volume.

Choose an area numb if possible.

Quick start with the trick Sellick.

Change kidney, water, electrolytes

The main tasks of the kidneys: maintaining blood pressure, water-electrolyte balance, excretion of metabolites azot.

In the first 3 months of pregnancy, progesterone dilates the renal pelvis and ureter. The uterus gradually enlarges easily causing retrograde infection.

Renal blood flow increases from week 5 and increases by 30% between pregnancy and then stabilizes until term.

Glomerular filtration increases 30-50% compared to before pregnancy.

Renal tubular reabsorption (water - electrolytes) increases to balance salt - water. Urinary glucose increased slightly. blood creatin and urea decreased, uric acid increased.

Salt reserves increase by 500-1000 mEq in the placenta, fetus and maternal outer space.

Salt balance: due to increased glomerular filtration, fetal demand, progestron's elimination effect, increased factors such as increased secretion of aldosterone and estrogen, increased renin-angiotensin activity, facilitating salt-water stagnation.

A slight decrease in blood electrolytes was associated with a decrease in osmotic pressure by about 10 mOsm / kg.

Changes in liver and glucose

Less changes in the liver :

Little change in liver flow, moderate decrease in BSP, unstable bilirubin and transaminase increase, increasing alkaline phosphatase, and 20% decrease in pseudocholinestherase (no clinical consequences). Due to a decrease in neoglucogen, fasting blood glucose at the end of the first 3 months of pregnancy while insulin increases in the second stage of pregnancy due to increased glucide related to insulin resistance due to vegetables and increased cetonic.

With regard to the lethargy :

Cholinestherase sufficiently hydrolyzes succinylcholine in term of pregnancy.

Any increase in maternal glucose (diabetes, high sugar transmission) causes a decrease in glucose and metabolic acidosis in the newborn due to increased insulin in the fetus, so not much sugar is given in obstetric.

Nervous system changes

Cerebral blood flow does not change significantly during pregnancy.

The increased rate of induction of anesthesia and increased sensitivity to halogen can be attributed to an increase in progestrons 10-20 times at term.

MAC is reduced by 25-40% compared to not getting pregnant.

A narcotic progestron enhances the effect of intravenous anesthetic, and an increase in beta endor- phin may also contribute to this effect.

Reducing the dose of anesthetic due to a decrease in the volume of the epidural and subarachnoid space, the increase in the sensitivity of the nerves to the anesthetic.

Altered alkali, acidosis, and protein can be seen in cerebrospinal fluid.

Epidural and subarachnoid pressure increases.

Anesthesia, for the abortion

In the absence of maternal pathology, general anesthesia is performed when the mother refuses to undergo regional anesthesia.

Although there are many advantages, but overall charm also faces many difficulties such as:

Gastrointestinal reflux into the lungs (Mendelson's syndrome). Many years ago, this incident accounted for the highest mortality rate in obstetric anesthesia due to the backflow of food molecules into the rabbit's tract, often at the onset of asphyxiation or from low pH gastric gastric juice. (2.5) will cause pneumonia and shock lung will cause patient death. But today, by applying some preventive measures, the cause of maternal mortality is reduced by 60%. To overcome this syndrome, people use some kind of 0.3M sodium nitrate solution in combination with cimetidine or ranitidine for patients taking 15-30 minutes of anesthesia, applying Sellick procedure from the beginning of patient's death. be conscious until the ballooning of the endotracheal tube is pumped.

We must always consider pregnant women with a full stomach even though the meal is> 4 hours away from the tissue. Gastrointestinal catheterization is not entirely effective, but it also has some benefits to reducing gastric pressure due to vomiting, resulting from less fluid intake.

For pregnant women, because the uterus is pushed up, the stomach tends to be horizontal, on the other hand, the anesthetic we use changes the Hiss angle of the stomach, and when using some pre-anesthetic drugs like atropine or Benzodiazepines can reduce subesophageal sphincter tone that also facilitates reflux. In case of gastric aspiration, the catheter must be withdrawn before intubation.

It is also recommended to use the method of ring cartilage and oropharyngeal numbness for intubation before anesthesia is injected. This method is difficult for inexperienced anesthetists.

Difficult endotracheal intubation: due to many reasons, either by anatomical structure or by trauma to old trauma, besides when pregnant, pregnant women are often fat and especially edema due to toxic pregnancy we must prepare well, including the anesthetic assistant, in order to avoid accidents.

Due to changes in respiratory physiology, the mother and fetus's hypoxia tolerance is very poor, if we prolong the time of intubation, it can cause death for mother and baby. So we must ensure the following principles:

Examination and planned preoperative intubation.

There are experienced addicts.

Give women a 100% oxygen scent for 5 minutes before intubation or 5 deep inhalations.

Use depolarizing muscle relaxants for endotracheal intubation. After intubation, you can use non-depolarizing muscle relaxants.

Use the anesthetic should be deep enough to avoid a spasmodic stimulus.

Between two endotracheal intubation must allow oxygen.

If it fails, give masque respiration until the patient breathes.

If possible, equipped with masque laryngé.

Above are the two most common and fatal complications in obstetric anesthesia.


According to foreign authors, only need to give anti-acid solution or if surgery is prepared, for benzodiazepines: oxazepam (Seresta); lorazepam (Temesta) or temazepam (Normison).

Giving atropine is not beneficial because:

Easily reflux.

Increased fetal heart rate.

Today we still use the classic formula and some new remedies include: Dolargan 50mg

Dimedrol 20mg diluted enough lOml intravenously each time 5ml 15 minutes before onset of anesthesia.

Give the patient a dose of 0.3M sodium citrate 15ml and cimetidine 200mg or ranitidine 15-30 minutes before onset of anesthesia.


100% oxygen 5 minutes before the onset of anesthesia or take 5 deep breaths before the anesthesia.

Thiopental 5mg / kg after disinfection, brushing and the surgeon is ready.

Injections of succinylcholin (suxaméthonium) ll, 5mg / kg, continue with masque respiration with 100% oxygen but not too high-pressure respiration will increase stomach pressure and uterine vasoconstriction.

Intubation after 45 seconds - 1 minute of suxamethonium injection, must be gently but urgently intubated with the number 7 catheter (smaller sonde not pregnant). Following fixed endotracheal catheterization and endotracheal balloon injection, the Sellick procedure should be used until endotracheal balloon is pumped.

Maintain anesthesia

Cho halothan 0.5%.

Injections of pancururonium (Pavulon) or vecuronium (Norcuron) 0.04mg / kg or tracrium 0.2mg / kg (unless the patient has a history of water retention).

Mechanical artificial respiration with Fi02 = 1 and breathing pressure 30cmH2O. With the process of using the drug as above, we do not have to inject any other drugs and absolutely do not inject thiopental without taking the pregnancy out.

The time from the time of anesthesia to taking the pregnancy from 8-10 minutes according to the authors is the most ideal to ensure the mother is quiet and her baby is not inhibited.

The faster the time from incision to the time of taking out the pregnancy (umbilical pair). If it is over 180 seconds, the Apgar score is usually <7 (not good).

If we have N20, at this stage we can give 50% NzO + 50% oxygen. N20 cut when incision of the uterus.

After conception, the sedation will return to normal like other operations, we use thiopental, morphine pain reliever such as íentanyl 2mCg / kg or alíentanil 8mCg / kg.

Ocytocin 5 units for intravenous administration and 10 units for infusion in 500 ml of solution.

Before taking the pregnancy out, absolutely do not infuse hypertonic glucose solution, even hypertonic glucose must be limited.

CPR after conception with Fi02 = 50%.

Can use prophylactic antibiotics after the umbilical pair.

Escape from charm

Respiration must be restored but pain relief for the patient when commencing peritoneal stitching. It is best to get breathing back naturally without using curare antagonists. According to our experience, the best respiratory recovery is a fundamental problem, although the patient is not awake, only withdraw the endotracheal tube when breathing is good and the patient opens his eyes and mouth at the request of the physician.

After surgery, if the patient has pain, it is possible to give pain relievers of the paracetamol group such as: prodaíalgan, diantanvic or even íentanyl at the dose of lmCg / kg.

Regional anesthesia technique for cesarean section

This is a technique used mainly in anesthesia, obstetric anesthesia in the world as well as the Institute for the protection of mothers and infants.

Today, the two most commonly used regional anesthesia methods are epidural and spinal anesthesia. Each method has its own pros and cons. But epidural numbness is still the ideal method for cesarean section. Of course, good practice of this method requires experience and good technology.

Compared with general anesthesia, regional anesthesia has benefits

For Mom:

Reduce the risk of inhalation of gastric contents.

The witness of the birth of the child.

Relieve the epidural pain behind the tissue.

Mother breastfed earlier.

For children:

Increased uterine blood flow will provide oxygen to the fetus better.

Ability to prolong the time of cesarean section.

There is no risk of drug-induced fetal and neonatal suppression.

Some disadvantages

The prolongation of the time from the effective decision to surgery to effective pain relief for surgery.

The drop in blood pressure in surgery, especially spinal anesthesia, will reduce uterine blood flow - vegetables make the fetal oxygen supply decrease, possibly leading to acute fetal failure.

Compare spinal numbness with epidural

Spinal numbness is technically easier and more effective for pain relief.

But spinal numbness lowers blood pressure faster and more strongly.

The pain relief level of spinal numbness is more difficult to correct.

Inability to inject more anesthetic during surgery.

More headache (5-15%) with 25G needle.

Contraindications to regional anesthesia

Absolute contraindications :

Refusal of pregnant women.

Congenital or acquired pathology of the coagulation system.

Are taking anticoagulant treatment.

Infection around the puncture site.

Acute pregnancy failure, requiring fast surgery.

Increased intracranial pressure.

Relative contraindications:

- The risk of increased blood clotting disorders:

Hematoma behind vegetables.

The fetus dies in the womb.

Systemic infection (temperature above 38 ° C).

Vegetable striker bleed.

The risk of hypotension:

Lack of circulatory volume, anemia.

There is a compression of the aorta.

Treatment of low blood pressure.

Use strong sympathomimetic beta drugs (stop the drug 2 hours before).

- Cardiovascular disease:

Mitral stenosis, aortic stenosis, increased pulmonary artery pressure.

Aortic stenosis.

The Fallot Trilogy.

Conduction disturbances in the ventricles.

- Neuropathy:

Medullary disease.

Meningitis less than 1 year.

Signs of meningitis due to viral infection.

Pinched nerve roots (easy to fail).

Hepatic impairment: loss of resistance to toxicity with anaesthetics.

Allergy to anesthetics are esters: cocaine, procaine, tetracaine of the less allergic tonsils: lidocaine, bupivicaine (Marcaine), mepivicaine (Carbocaine), etidocaine (Duranest), prilocaine (Citanest) ...

Regional pangolin techniques:


Prepare a general anesthetic.

Pregnant woman lying on her left side (or resting with a pillow under her right hip).

Place a 16G-18G peripheral intravenous infusion line.

Ringer lactate infusion (if not available, use 0.9% NaCl).

Mix ephedrine 2-4 ampoules (20mg) in 500ml infusion.

2 ampoules of ephedrine in 1 lOml syringe (be careful not to infuse hypertonic glucose or infuse more isotonic glucose without taking out the pregnancy).

Tagamet effervescent 200mg mixed in 30ml water, drink as soon as indicated surgery.

Monitor: electrocardiogram, arterial blood pressure, Sp02.

Oxygen by masque 3-4 liters / min.

Technique of epidural anesthesia:

Patients are allowed to lie down in a left or sitting position.

Carefully disinfect the back - waist area.

Locate to poke (L2-L3 or L3-L4).

Local anesthetic with lidocaine 2%.

Tuohy 18G needle puncture according to the technique of loss of fluid resistance (preferably an anesthetic for testing - lidocaine 2% + adrenalin 1 / 200,000).

If you pass the catheter, inject 5-7ml of nodule.

Insert the catheter into the epidural space 2 cm deep (need to relieve pain after surgery).

Wait 5 minutes after the test dose has effects on the mother's pulse (slow pulse, increased blood pressure) or the patient feels numb (due to spinal anesthesia)?

Administer small doses of anesthesia in small doses (if catheter is inserted) 4-5 ml with adrenaline 1 / 200,000 (if catheter is inserted or a single injection (15-16 ml) plus a test dose of 20 ml.

How to use the drug:

Or 2% lidocaine alone: ​​20 ml (including test dose).

Or lidocaine 2% 15ml + bupivacaine 0.5% 5ml.

Or lidocaine 2% 15ml + bupivacaine 0.5% 5ml + íentanyl 50-70mCg.

Or lidocaine 2% 15ml + bupivacaine 0.5% 5ml + suíentamil 10-15mCg.

So using tentanyl will reduce waiting time and increase pain relief time.

Administer ephedrine in doses according to the number of blood pressure.

After pair of umbilical cord:

Syntocinon (oxytocin) 5-10UI slowly intravenously and 10-15UI / liter for 8 hours.

Lay the patient flat on the operating table.

Stop infusing ephedrine.

Antibiotic prophylaxis intravenous injection.

After closing the abdominal wall:

Transfer the patient to the recovery room.

Watch for uterine contractions.

Monitor pulse, blood pressure.

Monitor recovery, movement and diabetes.

It is possible to prevent embolism after surgery.

Spinal anaesthesia techniques:

The patient lies on the left side or sits.

Carefully disinfect the lumbar area.

Locate to poke (L2-L3 or L3-L4).

Local anesthesia with lidocaine 2%.

Insert anesthesia needle> 27G, preferably a pencil tip.

Bupivacaine hyperbare injection 0.5% 10-12mg depending on height:

< l,5m: 8mg

l,5m < l,7m: 10mg

l,7m: 12mg

Can be combined with morphine 0.1mg.

Immediately place the patient on his or her left side slightly (15 °) or place a pillow below the right hip with the head resting slightly with a pillow.

Ephedrine infusion flow rate depending on the patient's blood pressure.

After pair of umbilical cord:

Syntocinon (oxytocin) 5-10UI slowly intravenously and 10-15UI / liter for 8 hours.

Lay the patient lying flat on the surgical table.

Stop infusing ephedrine.

Antibiotic prophylaxis intravenous injection.

After closing the abdominal wall:

Transfer the patient to the recovery room.

Watch for uterine contractions.

Monitor pulse, blood pressure.

Monitoring of motor recovery and in the patient with diabetes.

It is possible to prevent embolism after surgery.

Some points to note and refer to in regional anaesthesia:

Problems with hemodynamic monitoring in regional anesthesia:

The first 5 minutes after anaesthesia follow every minute / time.

After 5 minutes to 10 minutes every 5 minutes.

From 10-20 minutes every 10 minutes.

Over 20 minutes every 15 minutes.

Besides marcaine 0.5% hyperbare people also used lidocaine 5%, prilocaine 5%, mepivacaine 5%, tetracaine 0.5% for spinal anesthesia (Table 1).

If the maximum blood pressure drops> 20% or <lOOmmHg: put the patient on his left side and increase intravenous flow. If no results are found, the intravenous ephedrine injection is slow.

In case of pain relief is not enough for surgery, if spinal anesthesia needs to be converted to general anesthesia, if the epidural anesthesia with catheter is placed, add 5 ml of 0.5% bupivicaine or 50 pg of íentanyl via catheter.



Concentration (%)

Time of surgical anesthesia -> (minutes)

Duration of action (minutes)

Movement blockade

Closed feeling





















In addition to lidocaine and bupivacaine, there are also some anesthetics used in epidural anesthesia (table).



Duration of effective anesthesia (minutes)

Duration of action (minutes)

Getting started


Movement blockade

Closed feeling












100 ±40






100 ±80






200 ± 80






170 ±60










168 ±60

180 ±30

180 ±30

Morphine drugs used in spinal and epidural anesthesia cesarean section (table).


Pethidin (Dolargan)


TeTS: 0.25-1 mg / 1 time NMC: 0.05 - 0.1 mg / kg

Pangolin: 1mg / kg / 1 time

1mCg/kg: NMC

Combined with anesthetic for:

Increased pain relief in surgery (±)

Postoperative pain relief +++

After 3-5 minutes, it works to relieve pain

Pain relief time: 70 minutes

Combined with anesthetics to:

- Increased pain relief in surgery Pain relief after surgery +++

Possible: nausea, vomiting, itching

Nausea, vomiting, itching (+)

Nausea, vomiting, itching (±)

Risk of respiratory depression 1%

Does not inhibit maternal breathing

No secondary respiratory depression

Does not affect newborns

No neonatal effects were observed

Does not work on children

TS: NMC: epidural

The main complications are common in anaesthesia - obstetric anaesthesia

As with general anaesthesia, there are many complications that are common in all stages of anaesthesia. In obstetrics, these complications are also possible. In the scope of this article, we will study some typical complications that are common in obstetrics and the risk of maternal, fetal and neonatal mortality.

Mendelson Syndrome

Assembly c improvisation Mendelson common in obstetrics by :

Due to changes in the physiology of the gastrointestinal tract, all pregnant women are considered to have a thick stomach.

Change of stomach posture, open Hiss angle due to anesthesia, lower esophageal sphincter tone due to use of pethidine, atropine, increased stomach pressure due to use of depolarization muscle relaxants when intubated.

Gastrin secretes gastrin increases stomach volume and increases acidity.

As a result, airway obstruction due to food particles, lung edema can be superinfected, it is worse when gastric pH <2.5 and inhalation volume> 25 ml.

Provision ch Assembly stasis ng Mendelson :

Ask the pregnant woman to fast or drink when the uterus is in contractions or when she starts entering the delivery room.

Controlling the pH of gastric juice: using two drugs:

0.3M sodium citrate is a quick-acting solution suitable for first aid. Dosage is 30ml orally as soon as indicated for surgery. Short duration of action (45 minutes), if surgery is prolonged, the effect is limited.

Histamine's H2 recepteur drugs include cimetidine and ranitidine. These two types have a long duration of action but start to work slowly (limited in first aid). Effervescent type tagamet can be used, with faster effects. This drug must be given systematically even under regional anesthesia.

Combination of 0.3M sodium citrate with cimetidine is both fast and long-lasting effect.

Controlling gastric contents: metoclopramide (Primperan) reduces the contents of the stomach, increases the tone of the suboesophageal sphincter, antiemetic but slow effect. Dosage of lOmg intravenously. Time to empty the stomach is 20 minutes, but the drug 5 minutes before anesthesia lose the effect of spasm dilation under the esophagus due to atropine and pethidine. It empty the stomach even when using morphine.

As designated obstetric

Surgery according to the program:

Fasting from 0 o'clock.

Cimetidine effervescent 200mg orally 15 minutes before onset of anesthesia.

First aid surgery:

Duration> 5 minutes: Cimetidine effervescent 200mg orally before entering the operating room.

Primperan 10mg intravenously slowly.

Duration <5 minutes: 0.3M sodium citrate 30ml orally.

Rapid intubation: It is also a way to limit this syndrome. To do this, you need deep enough anaesthesia and use depolarizing muscle relaxants (time <1 minute).

These types of muscle relaxants are prone to allergies and increase stomach pressure. The pre-Curare method can be used.

Use the Sellick procedure from loss of consciousness due to anesthesia until the end of the endotracheal balloon pump.

Difficult intubation

Also common in obstetrics due to physiological and anatomic changes in pregnancy:

Increased anterior and posterior diameter, breast enlargement, mucosal capillary edema (especially fetal toxicity), and even Sellick's procedure distorts.

Inexperienced anesthetist, anxiety is also a cause.

Congenital or acquired malformations, deformities.

The rate of difficult endotracheal intubation in obstetrics is 1/300 while the rate 1/2000 for general surgery.

How to detect :

Relying on Mallampati (Cormack and Lehane) mainly.

Refer to the VVilson index. Index YVilson> 2 has 75% difficulty endotracheal intubation.

Prevention and treatment:

In the past, when the premature death rate from Mendelson's syndrome was high, nowadays, intubation is difficult, and the mortality rate is higher.

Due to its emergency nature, pre-anaesthesia evaluation is often insufficient.

An anaesthetist and an experienced anaesthetist are needed.

There is an endotracheal instrument box.

Use new endotracheal depolarization muscle relaxants to use nonpolar muscle relaxants.

Need to have a monitor to monitor blood gas.

It is best to undergo regional anesthesia if there are no contraindications.

Compression syndrome

Very common in obstetrics either intense or discreet. It is pressed by the pregnant uterus against the lower aorta (supine), reducing venous blood returning to the heart and reducing cardiac output causing hypotension and decreasing vegetable perfusion causing acute fetal failure.

Lower blood pressure

Hypotension in obstetrics is also very common, especially the cause of bleeding and is more favourable when there is a syndrome of compression, regional anaesthesia.

The consequences of hypotension can be fatal to the mother and to the fetus. Lower blood pressure as much and prolonged as serious consequences.

It is called hypotension when the maximum blood pressure is <lOOmmHg or> 30% lower than the blood pressure before anaesthesia.

Precautions and treatment:

Preventing host pressure syndrome.

Anaesthesia for bleeding cases with drugs that do not inhibit myocardium and vasodilators (Ketamin, Etomidate should be used) and use Fentanyl pain reliever.

If regional anaesthesia requires an infusion of 10-20 ml/kg of Ringer lactate solution before anaesthesia, use ephedrine systematically before regional anaesthesia and should not exceed 50 mg because it is easy to inhibit myocardium. If ephedrine is ineffective, adrenalin can be used.

Raise your lower extremities and do not keep your head low during hyperbaric anaesthesia.

The neurological signs are the earliest symptom of decreased cerebral blood flow. If treatment is late or incorrect, the circulation can stop and aggravate nerve damage.

Respiratory complications

Common in general anaesthesia and anaesthesia:

In obstetrics or regional anaesthesia, if the anaesthetic blocks the movement too broadly, those with chronic respiratory failure or taking a lot of sedatives may develop premature respiratory failure. Respiratory failure can occur with a combination of morphine and spinal anaesthesia.

Handling :

Allow oxygen to pass through the mask.

If hyperventilation is severe, then artificial respiration is intubated.

Naloxone (Narcan) is required if morphine is involved.

Headache after anaesthesia


Common in spinal anaesthesia due to cerebrospinal drainage to the epidural space (puncture site) reduces the secondary pressure in the spinal cord causing contraction of the brain - meninges.

Pain is usually related to sitting or standing position, strong light, noise and headache associated with hearing and vision loss.

Two main factors cause headaches:

Large needle: 1-15% with 25 needles. If needle 27, rate of headache 0.5-1%. If the needle is 29, there is no headache. Using a pencil needle is very little headache.

Gender and age: female and 20-30 years old more headache.


Depends on the level of progression.

Normal form:

Lie on your back completely, support your feet high.

Drink plenty of fluids or fluids.

Use the pain reliever, paracetamol family.

If the effect is poor, then drink coffee or intravenous caffeine 200-400mg, then repeat after 3 hours.

Severe form: applying the method "Blood path": taking the patient's venous blood and injected it into the epidural space. This method is 70-98% effective.

So cold

Meet a very high rate with anaesthetic epidural 50% :

The physiology of the disease is not clear, but people often think of:

Pregnant women are worried.

Cold ambient temperature.

Fluid infusion, especially cold.

Spinal tube heat receptor stimulation due to cold aesthetic.


Injections of pethidine (Dolargan, Dolosal) 0.03-0.05 dose intravenously.

Or injections of catapressan (Clnnidine) 0.15mg (1/2 ampoule) intravenously.

The operating room is warm, warms infusion and anaesthetics.

Vomiting - nausea

Causes :

Also common in regional anaesthesia due to hypotension reduces cerebral blood flow causing a lack of cortical oxygen, which stimulates the Postrema region and induces vomiting.

Handling :

Use ephedrine to treat hypotension.

Give pregnant women oxygen.

Limit the strong effect on the uterus and peritoneum because the strong effect on the uterus and peritoneum will affect the vagus nerve reducing heart rate and cardiac output.