1、Obstetric Anesthesia Physiologic Changes Of Pregnancy Respiratory System : increase in the respiratory minute volume and work of breathingGastrointestinal System : risk of incidence of aspirationendotracheal intubation Renal System : GFR rises 50% ; glycosuriaCentral Nervous System : sensitivity to
2、anesthetics. Changes Of Respiratory System mO2 (Consumption 消耗 ) +20 to +50%mMV(Minute Ventilation分钟通气量)+50%mTV +40%mPaO2 +10%mPaCO2 -15%mHCO3 -15%mFRC -20%Placental Transfer Of Anesthetic Drugs Placenta transport : Simple diffusion Facilitated diffusion Active transport PinocytosisReadily cross : l
3、ow molecular weights, high lipid solubility , non-ionized Approximately 50% of the umbilical venous blood bypasses the liver.mNarcotic analgesic morphine pethidine fentanyl alfentanil sufentanil mGeneral anesthetics propofol m吗啡、哌替啶、芬太尼Morphine Morphine mPlacental transfer is rapidmMother: uterus re
4、activeness orthostatic hypotension nausea vomiting delayed gastric emptyingmFetus: respiratory depressionPethidine Pethidine mMost commonly used during labor intramuscular dose : 50 -100 mg Time of IM: before expulsion 1 h or 4 huterine contraction, frequency and intension Fentanyl Alfentanil Sufent
5、anil Fentanyl Alfentanil Sufentanil Placental transfer is rapid Low dose: 10 -25 g fentanyl or 5-10 g sufentanil in subarachnoid space PCEA: low dose of fentanyl and 0.1%-0.3% ropivacaineTramadol Tramadol m Placental transferm No inhibiting uterine contractionm No Respiratory depressionDiazepam m Re
6、adily cross the placenta Half-lives: 48 hours Problems: sedation, hypotonia, cyanosis, impaired metabolic responses to stress. MidazolamMidazolamm Plasma protein binding: 94%m Respiratory depression: depended on dose 0.075 mg/kg no problem 0.15 mg/kg different degree Droperidol m Pregnant woman: 慎用m
7、Apgar score Thiopental sodiumm Neonatus sleep: littlem Premature and intrauterine embarrass: carefully usingKetamine High doses (greater than 2 mg/kg) may cause low Apgar scores and abnormalities in neonatal muscle toneLabor pains of uterine contractionUterine muscular tension and contraction forceC
8、ontraindication: psychosis, gestational hypertension syndrome or preeclampsia, metrorrhexisPropofol Propofol m Recommendation: induction: 2.5 mg/kg maintenance: 2.5-5.0 mg/kg/hm Discontinue gravidity onlyNN2 2OOm Placental transfer is rapid Mothers respiration, circulation and Uterine muscular contr
9、action force 20-30s before of first stage of labor: 50% O2 and 50% N2O, maximumhalothaneSuccinylcholineSuccinylcholine m Cholinesterase: normal doseno placental transfer Dose 300 mg or single dose is larger: still have placental transfer Nondepolarizing Muscle Relaxants mOnset is quick, maintanence
10、is short and placental transfer is leastmAtracurium: 0.3 mg/kgLocal anestheticsLocal anestheticsFactors:Protein binding: Molecular weightLiposolubility Catabolism in the placentLocal anestheticsLocal anesthetics m Procainem Lidocaine m Bupivacaine m RopivacaineAnesthesia For Sesarean Section Choice
11、depends on : the indications for the surgery the degree of urgency maternal status desires of the patientSpinal Anesthesia m Hyperbaric bupivacaine m Advantages : rapid onset, little risk of local anesthetic toxicity, minimal transfer to the fetus, infrequent failure. Disadvantages : finite duration
12、 hypotension headacheEpidural Anesthesia m L 23 or L 12 1.5%2% Lidocaine or 0.5% Ropivacaine emergency cesarean sectionCombined Spinal-Epidural Technique Increased dramatically in popularity Advantages : rapid onset supplemented at any time anesthetic dose sacral nerves block is sufficientGeneral An
13、esthesiam rapid induction: obviate positive pressure ventilation oppress the cricoid cartilagem mainterance: light anesthesiam vomiting, backstreaming and aspiration: atropine, 0.5 mg, IM or glycopyrolate, 0.2 mg, IMSupine hypotensive syndrome m Incidence: 2%30%m Time: after 28 weeks, specially 3236
14、 weeksm Symptoms: hypotension, dizziness, nausea, chest distress, cold sweat, to yawn, pulse rate, pallescenceHigh risk pregnancyHigh risk pregnancy Emergency operation : late trimester of pregnancy: hemorrhage gestational hypertension syndrom and eclampsia Selective operation : hypertension cardiac
15、 disease diabetes multifetation Placenta Previa and Placental Abruption Preanesthtic preparation: blood coagulation function DIC sifting test acute renal failure Principle: general anesthesia: active bleeding, hypovolemic shock, definite blood coagulation disfunction or DIC intraspinal anesthesia: c
16、ondition of mother and fetus is okay Managementdegrees of abruptio placentae. A, Concealed hemorrhage. B, External hemorrhage. C, Complete placental separation. Types of placenta previa. Management of anesthesiaManagement of anesthesia Announcements of the induction: difficult airway cricoid cartila
17、ge backstreaming and aspiration Prepare to salvage the blood coagulation disfunction and the hemorrhoea. Prevent the acute renal function failure: urine volume urea nitrogen and creatinine Prevention and cure of DICPregnancy-induced Pregnancy-induced hypertension syndromehypertension syndrome Incide
18、nce: 10.3% Cause of death: cerebrovascular accident, pneumonedema, liver necrosis Pathophysiology: systemic arteriola systole, fetus Management: HELLP syndrome HELLP syndrome m cardiac failurem cerebral hemorrhagem placental abruptionm blood coagulation disfunctionm haematolysism hepatic enzymem thr
19、ombocytopeniam acute renal failureManagement 1Management 1m trying stable anesthesia: stress reaction: fentanyl avoid to use ketamine SBP: 140150 mmHg, DBP: about 90 mmHg ganglioplegic or nitroglycerinm maintain heart, kindey and lung function: m treatment of complication: Management 2Management 2m
20、basic monitoring: ECG SpO2 NIBP CVP urine volume blood gas analysism prepare to salvage the neonatal asphyxiam ICUm postoperation analgesiaMultiple Births pathophysiology: abdominal aorta and inferior vena cava compression; fetal lung maturity; incidence of postpartum hemorrhage. anesthesia: epidura
21、l anesthesia management: addition of volume: colloid oxygen, prevention and cure of Supine hypotensive syndrome preparation of resuscitation of newbornNeonatal asphyxia and Neonatal asphyxia and emergency treatment emergency treatment ASSESSMENT OF THE FETUS AT BIRTH Apgar score is a simple, useful
22、guide - The Apgar scoring system Score * Sign 0 1 2 Heart rate Absent Less than 100/min More than 100/min Respiratory effort Absent Slow, irregular Good, crying Color Blue, pale Body pink, extre mities blue (acrocyanosis) Completely pink Reflex irritability (response to insertion of a nasal catheter
23、) Absent Grimace Cough, sneeze Muscle tone Limp Some flexion of extremities Active motion Apgar score Apgar score m 1-minute score - degree of asphyxiam 5-minute score - prognosism evaluated at 1 and 5 minutes.m should not wait until 1 minute has passed before initiating resuscitation.m normal: 7-10
24、 mild asphyxia: 4-6 severe asphyxia: 0-3 Resuscitation of newborn Resuscitation of newborn m A ( Airway)m B ( Breathing)m C (Circulation)m D (Drug)m E (Evaluation)Initial resuscitation Initial resuscitation m Incubation: 2731m Position: m Suctioning: mouth and nosem Stimulate: Complete it within 20s
25、Evaluation and further Evaluation and further treatmenttreatmentm Evaluation: according to breath, heart rate and skin colourm Normal: stop resuscitation m No spontaneously brathing, HR100/min: bag respiratorm HR80/min: closed cardiac massage; tracheal intubation, medicationBag respiratorBag respira
26、torm Maniphalanx pressurizem Tidal volume: 2040mlm I : E = 1.5:1m RP: 3040/minm first twice: pressure 3040 cmH2O subsequently: pressure 1020 cmH2ORESUSCITATION EQUIPMENTClosed cardiac massage Closed cardiac massage HR: 120/minDepth: 12cmRESUSCITATION DRUGS m 30s after the closed cardiac massage, sti
27、ll cant recovery : drugm Epinephrine: 0.10.2mg/kg, intratracheal drop inHypovolemia causescausesm umbilical cord was clamped and cut earlierm intrauterine asphyxiam placental abruptionm hemorrhage too much: antepartum or intrapartumDetection of Hypovolemia m arterial blood pressure and CVP pale skin
28、 poor capillary refill extremities are cold pulses are weak or absentTreatment of HypovolemiaTreatment of Hypovolemia m intravascular volume expansionm blood, plasma ,crystalloid , Albuminm 10 mL/kg of normal saline, 1 to 2 g/kg of 25% albumin, or 10 mL/kg of plasma.m Care must be taken Correction o
29、f Acidosis Respiratory acidosis is corrected by controlling ventilationMetabolic acidosis is corrected by infusing sodium bicarbonate.Requisite amount of sodium bicarbonate(mmol): = 0.6BW(kg)(normal BE-present BE)/4 sodium bicarbonate 1 mmol/kg/minSodium bicarbonate should not be infused unless vent
30、ilation is adequate. Monitoring After resuscitationMonitoring After resuscitationm temperaturem breathm heart ratem blood pressurem urine volumeGynecologic anesthesiaGynecologic anesthesia Special position: head down and lithotomy position Old age: comorbidities Emergency case: exfetation, ovarian cyst intortion, perineal position trauma, uterine perforation More other: selective operation Hysteroscope and Laparoscopic Surgery:
