临床麻醉学-理论教案:第二十六章(双语)

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临床麻醉学:理论教案第二十六章(双语）:临床麻醉学教研室理论教案课程名称临床麻醉学年级专业、层次麻醉本科授课教师职称课型（大、小) 大学时 4 授课题目（章、节) 第二十六章妇产科麻醉（双语) 基本教材及主要参考书（

临床麻醉学教研室理论教案

课程名称

临床麻醉学

年级

专业、层次

麻醉本科

授课教师

职称

课型（大、小)

大

学时

授课题目（章、节)

第二十六章妇产科麻醉（双语)

基本教材及主要参考书

（注明页数)

徐启明，主编. 临床麻醉学. 北京：人民卫生出版社. 2005(第二版)

刘俊杰，主编. 现代麻醉学. 北京：人民卫生出版社. 1997

Miller. Anesthesia. 北京：北京大学医学出版社. 2003

教学目的与要求：

目的：熟悉妇科麻醉的特点、麻醉选择和常见手术的麻醉；掌握麻醉药对母体及胎儿的影响；了解胎盘的运输功能、胎儿及新生儿的药代特点；掌握产科麻醉的准备和注意事项、剖宫产术的麻醉、妊高征的麻醉注意事项；熟悉新生儿窒息的评估，掌握新生儿复苏方法；

要求：

1、掌握麻醉药对母体及胎儿的影响；

2、掌握产科麻醉的准备和注意事项、剖宫产术的麻醉、妊高征的麻醉注意事项；

3、熟悉新生儿窒息的评估，掌握新生儿复苏方法；

4、熟悉SHS的病因病理、临床表现、判断与防治。

内容与时间安排，教学方法：

妇科麻醉gynecological anesthesia （30分钟)

产科麻醉Obstetric anesthesia （130分钟)

麻醉药对母体和胎儿的影响The effects of anesthetics on mother and fetus：（45分钟)

胎盘屏障对麻醉药物的影响The effects of placental barrier on anesthetics ：（20分钟)

产科手术的麻醉Anesthesia for obstetric procedures： ( 45分钟 )

新生儿窒息与复苏Neonatal asphyxia and resuscitation ：（20分钟)

方法：CAI, 大量图片简图加深感性认识，简表对比加深理解，布置一些内容自学，尝试课堂讨论

教学重点、难点：

重点：麻醉药对母体及胎儿的影响；产科麻醉的准备和注意事项、剖宫产术的麻醉；新生儿窒息的评估，新生儿复苏方法；

难点：麻醉药对母体及胎儿的影响；新生儿复苏方法；

教研室审阅意见：

教研室主任签名：

年月日

Anesthesia for gynecological procedures

The characters of anesthesia for gynecologic procedures

1. Pelvic and vaginal Ops need excellent painlessness and muscular relaxation; Pay attention to affection to respiratory and circulatory functions due to

2. Most of gynecologic patients are aged and complicated with HP, CAD, Diabetic, COPD, anemia, etc.

3. Most of procedures are selective and pre-operative preparation should be well done.

Choice of anesthesia

CEA(one-point-puncture or two- point-punc ture), SA, GA can be chosen accordingly.

The anesthesia for common gynecologic procedures

1. 子宫切除术-hysterotomy；附件切除术-salpingo-oophorrectomy；

2.巨大卵巢肿瘤切除术-resection of giant oval tumor；

3.宫外孕破裂-rupture of ectopic pregnancy；

4.宫腔镜检查和手术-hysteroscopy and hysteroscopic procedures；

The characters of Obstetric anesthesia

The effects of anesthetics on mother and fetus

NARCOTIC ANALGESICS: Almost all narcotic anesthetics are easily to pass through placenta and therefore inhibit fetus.

1.Morphine: It has already, as an extraindication, been abandoned to use for obstetric anesthesia and analgesia for a long time.

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2. Pethidine: A large number of clinical investigations revealed that low dosage of fentanyls alone or combined with some LA in low concentration can be applied safely for intrathecal analgesia during labor.

3. Fentanyls: A large number of clinical investigations revealed that low dosage of fentanyls alone or combined with some LA in low concentration can be applied safely fo r intrathecal analgesia during labor.

NON-NARCOTIC ANALGESIC: Tramal is safe for obstetric anesthesia and pain-relieving.

NON-BARBITORATE sedatives:

1. Diazepam: Its use should be cautious.

2.Midazolam: It’s better to avoid it peri-anesthetically.

3.Chlorpromazine: Rarely used at present.

4. Droperidol: It’s easy to pass through placenta and may result in poor neonatal Apgar’s score and neurobehavioral score.

Barbiturates: it may rapidly appear in umbilical blood after use and may result in poor neonatal Apgar’s score and neurobehavioral score.

LOCAL ANESTHETICS: Factors related to diffusion rate of LAs through placenta are as follows:

a. maternal plasma protein-binding rate: Ropivocaine 94%±1%, Bubivocaine 84%~85%, Lignocaine 51%~64%.

b. molecular weight of LAs: All < 400.

c. lipi药品数据d-solubility of LAs.

d. metabolism rate of LAs in placenta.

(1) Procaine: It penetrates placenta 3~5 min after local infiltration, but has almost no undesirable effects on neonatal breath and uterine contraction.

(2) Lignocaine: Half of maternal blood level will be reached 3 min after epidural injection, but without direct effect on neonatal Apgar’s score and neurobehavioral score when used in clinical range of dosage.

(3) Bubivocaine: It’s not recommendable for obstetric anesthesia because of cardiac intoxication which is usually difficult to rescue.

(4) Ropivocaine: This is a newer long action LA. Several properties (higher protein-binding rate, shorter half life comparing with Bubivocaine, peripheral vasoconstriction, etc.) of it determine that it’s more valuable as an obstetric anesthesia.

GENERAL ANESTHETICS

1. Ketamine: It’s contraindicated for patients with psychological problem, pregnant hypertensive syndrome, eclampsia and uterusrupture.

2.γ-OH: It’s rarely used now.

3. Thiopental: It should not be used over 7mg/Kg.

4. Propofol: Its use in obstetric anesthesia is not suggestive (except anesthesia for terminating pregnancy), according to instruction of use, and postpartum breast-feed might be unsafe for baby.

5. Nitrous oxide: Patient can intermittently inspirate N2O 20~30s before uterine contraction in first stage of labor at 50% (<70% at most) in oxygen.

6. Fluothane: It’s contraindicated in those who are vaginal deliverer.

7. Isoflurane, enflurane, sevoflurane, and desflurane: They are widely used at present as much safer choices.

MUSCULAR RELAXANTS

1. Suxamethoniium succinylcholine: It does not almost shift to fetus at clinical range of dosage (<100mg or <300mg in total) for its high lipid solubility and fast breaking down by cholinesterase.

2. Non-depolarizing relaxants: But it should be administered cautiously because its residual relaxation may result in lowered neonatal NACS sometimes.

The effects of placental barrier on anesthetics

Transport through placenta

1. Simple diffusion: It’s the most important way of placental exchange of substances.

2. Augmented diffusion: Some high molecular substances can penetrate placenta by a transporting system so called augmented diffusion.

3. Active deliver or transmission: Therefore active deliver or transmission is an energy-consumptive process.

4. Special ways: There are two special ways of transmission (of immunological molecule) in main: a ; b Seepage: .

PHARMACODYNAMIC CHARACTERISTICS OF fetus andneonates

Drugs are firstly metabolized or broken down in fetal liver by 50% after entering fetus and become more diluted before reaching to fetal cerebral circulation. Permeability of fetal or neonatal blood-brain barrier is relatively higher, especially when CO2 accumulation and hypoxemia exist.

Fetal or neonatal GIR (glomerular infiltration rate) is only 30~50% of adults and excretion rate is 20~30% lower than adults, which means they are less capable of eliminating drugs.

Fetal or neonatal liver is around 4% of their body weight (2% in adults), but activity ofhepatic P-450, NADPH etc, is lower than that in adults.

Anesthesia for obstetric procedures

Preoperative preparation and its key-points

Anesthesiologists must review patient’s past history, family history, obstetric condition or problem, preoperative preparation, etc. as much and exhaustive as possible within limited time before procedure for the reason that most patients who are undergoing cesarean section are emergent.

Regurgitation and aspiration of gastric content must be effectively prevented immediately after vomiting occurs during anesthesia. Regurgitation may result in mortal outcome in both mother and fetus. For this reason, preoperative fast should be preceded as possible.

As to patients with obstetric complications such as pregnant hypertensive syndrome, preeclampsia, eclampsia and obstetric hemorrhage, corresponding preparation should be considered.

Anesthesia for cesarean section

(1) Local infiltration anesthesia: It’s indicated in patients with full stomach, intrauterine fetal asphyxia, and in patients in whom general anesthesia may be particular hazardous.

(2) Spinal anesthesia (SA): Advantages of SA include its simplicity, small drug dose, low failure rate (3%), rapid onset and complete blockage.

(3) Combined spinal/epidural anesthesia (CSE): Potential problems of CSE include the inability to “test” the epidural catheter for proper location and the enhanced spread of previously injected spinal drug following the epidural injection.

(4) Continuous epidural anesthesia (CES): Flexibility is probably why EA is used more often than SA. Epidural space is often punctured at L2~3 or L1~2 vertebral interspace with 1.5%~2% Lignocaine or 0.5% Ropivocaine.

(5) General anesthesia (GA): Its advantages include rapid induction, less associated hypotension and cardiovascular instability, and better control of the airway and ventilation.

Supine hypotension syndrome (SHS) and its prevention and treatment

SHS is the result of compressed inferior vena cava by enlarged uterus and may follow onset of EA. It’s manifested primarily as hypotension, tachycardia, collapse and faint. Prevention and treatment of SHS involve pre-emptive infusion of IV fluids, displacement of uterus to left manually or by a displacer, ensuring proper maternal position with the uterus displaced off the vena cava, administration of oxygen to the mother, use of head-down tilt, and administration of ephedrine, 5~10 mg IV.

Anesthetic considerations

for High risk pregnancy

-------------------------------------------------------

Placenta previa & abruptio placentae

Main problem: bleeding- blood loss- shock-DIC; Choice of anesthesia: GA v.s CEA;

Anesthesia & management: induction; ready to deal with abnormal coagulation and terrible blood loss; protection of renal function from failure; ready to prevent and treat DIC;

Anesthesia for patient with pregnant hypertensive syndrome

The special anesthetic considerations:

(1) Patient may be dehydrated to various degrees and hypovolemia because of preoperative intake limitation of crystalloid solutions and use of diuretics and manital.

(2) High doses of sedatives-tranquilizers and anti-hypertensives are usually administered to the patients, which may not only enhance the effects of anesthetics, but increase the incidence of hypotension, respiratory depression, etc.

(3) Hypertensive cardiopathy, insufficiency of left heart, pulmonary edema, renal failure, electrolytes imbalance, cerebral hemorrhage, DIC, etc. may exist or occur in patients with preeclampsia or eclampsia peri-anesthetically.

(4) EA is extraindicated when patient is in use of heparin.

(5) Unnecessary stimulation should be avoided and proper sedatives-tranquilizers may be used to relieve anxiety.

Choice of anesthesia: CEA v.s GA;

Intraoperative management:

Anesthesia for patient with pre- eclampsia and eclampsia

Preoperative preparation:

Choice of anesthesia: CEA or GA;

Management:

Anesthesia for patient with multiple pregnancy

Choice of anesthesia: CEA or GA;

Management:

Neonatal asphyxia and resuscitation

Neonatal asphyxia and evaluation

(1) Manifested as no breathe after birth.

(2) Apgar scoring (summarized in table as follow):

(3) Blood gas analysis: more accurately evaluated by pH, PaO2, PaCO2, etc. Neonatal resuscitation

Resuscitation steps:

A. (Airway): To establish and maintain patent airway.

B. (Breathing): To establish breath.

C. (Circulation): To establish normal circulation.

D. (drugs): Drug administration.

E. (Evaluation): on the base of respiration, heart rate and color of skin before further steps.

a. Resuscitation can be stoppe d when normal respiration and HR (>100bpm) demonstrate.

b. Manual ventilation and oxygenation should be continued with re-expansion bag if no spontaneous breath or only abnormal respiration can be seen, and HR <100bpm. Neonate should be intubated and assisted by manual ventilation (VT=20~40ml, I/E=1.5/1, 30~40 bpm, compression force=20~40 cmH2O) and drugs when HR <80 bpm and external cardiac massage (at least 100 bpm) failed to improve this situation. A rhythm is very important: five sternal compressions are given for each breath. A pause is given after each five sternal compressions to allow adequate lung inflation.

There are two correct hand placements for CPR in infants: 1both thumbs can be placed over the sternum while the fingers are curved around the back over the spine; 2one hand can be placed behind the back for support while sternal compressions are done with two fingers of the other hand.

(3) The commonly used drugs for resuscitation:

(4) Correction of hypovolemia:

It manifests mainly as pale skin, cold limbs, delayed capillary filling time, weak pulse, low BP and CVP.

It can be corrected by infusion of fluidsthrough umbilical vessels.

(5) Correction of acidosis: Respiratory acidemia can often be corrected simply by improved ventilation. Sodium bicarbonate 2mmol/Kg (5%sodium bicarbonate 1ml=0.6mmol) should be injected intravenously and slowly when Apgar 1min score <2 or Apgar 5min score <5.

(6)Warm-keeping: Environmental tem- perature of 34℃ should be kept to lessen the difference of room and skin temperature and rescue activity should be practiced with the baby put on a warmed table.

Monitoring after resus- citation

Monitoring after resuscitation includes at least BT, R, HR, BP, SpaO2, urine output, etc.

图片／示意图

介绍

图片

动画

讲解

（★－重点，☆－难点，)

完善的镇痛与肌松；体位（截石位)的影响；

注意合并症的治疗和纠正；

多为择期；做好准备；

★病人特点；麻醉选择；麻醉方法