All anesthesia residents in the Mount Sinai training program spend 2-3 months of their residency with the division of Obstetric Anesthesiology. Additionally, time is spent on the labor floor throughout the 2nd and 3rd year of your training in the evening as part of your on-call obligation.

The role of the obstetrical anesthesiologist has changed dramatically over the past few decades, from the days when OB anesthesia meant the administration of an inhalation anesthetic, usually delivered by the least trained physician, to the present, when the obstetric anesthesiologist is an integral part of the obstetrical team. We administer anesthesia to antepartum patients, to patients in labor and for cesarean deliveries. The labor floor no longer serves solely as a birthing unit, but also as a critical care area for preterm patients, as well as for parturients with medical complication of pregnancy. The obstetric anesthesiologist serves as the critical care consultant to the obstetrician.

To serve as a consultant requires much more than the ability to establish an epidural or spinal block. A thorough understanding of the physiologic adaptation to pregnancy as well as maternal-fetal interactions is necessary in order to safely manipulate maternal and fetal physiology during the administration of anesthesia. With the increasing recognition of the important role which good anesthetic management can play in the peripartum period, a thorough background in the field of obstetrical anesthesia is more important than ever.

Educational Objectives

We have well-defined objectives for you to accomplish during your time on the labor floor. These objectives are accomplished through clinical experience, bedside teaching, journal club and formal lectures.

1. Maternal physiologic changes of pregnancy.

   A. Maternal cardiovascular adaptation
       1. Intravascular volume change
       2. Changes in cardiac output
           a. antepartum
           b. peripartum (during labor)
           c. postpartum
       3. Aortocaval compression/supine hypotension
           a. normal compensatory mechanisms
           b. potential effects of regional anesthesia
       4. Potential effects of cardiovascular changes on the rate of an
           intravenous or inhalation induction of general anesthesia
   B. Determinants of uterine blood flow, including the effects of regional
        and general anesthesia on uterine blood flow
   C. Respiratory changes
       1. Changes in lung volumes and capacities
       2. Change in normal values of an arterial blood gas
       3. Why an inhalation induction may be faster
       4. Effect of pregnancy on the rate of arterial oxygen desaturation
           during apnea
   D. Gastrointestinal changes
       1. Changes in gastric pH and volume
       2. Mendelson's syndrome
       3. Aspiration prophylaxis
           a. particulate vs. nonparticulate antacid
           b. H2 blockers
           c. use of metoclopramide
       4. Changes in liver function
           a. drug metabolism
           b. serum cholinesterase levels
           c. albumen production
           d. production of clotting factors
           e. production of thyroid binding globulin
   E. Renal changes, including the change in GFR
   F. Endocrine changes
       1. Thyroid function
       2. Glucose metabolism
       3. Diabetes mellitus
           a. white classification of diabetes
           b. insulin treatment
           c. potential effects of maternal hyperglycemia on the newborn,
               including potential complications of maternal administration
               of glucose-containing intravenous solutions

2. Preoperative evaluation of the obstetric patient.

   A. History and physical examination
       1. A thorough history and physical exam must be performed on all
           patients prior to the administration of anesthesia, including maternal
           blood pressure
       2. Implication of maternal hypertension
       3. Potential airway changes associated with pregnancy
       4. How to determine which laboratory tests are indicated, and interpret
           the results
   B. Pre-anesthetic fetal evaluation
       1. Significance of fetal abnormalities on the anesthetic management
           of the parturient
       2. Fetal heart rate monitoring
           a. fetal heart rate variability
           b. how to identify early vs. late vs. variable decelerations, and the
               significance of each
       3. Monitoring uterine contractions
           a. normal contraction pattern
           b. significance of uterine hyperstimulation
       4. Fetal acid-base status
           a. normal values for a fetal scalp blood pH
           b. significance of a low fetal scalp pH

3. Special problems encountered in obstetrical patients.

   A. Potential difficult airway
   B. Increased risk of aspiration
   C. Hypertensive disorders of pregnancy, including their differential
       diagnosis
       1. Define chronic hypertension, gestational hypertension, preeclampsia
           and preeclampsia superimposed on chronic hypertension
       2. Potential etiology of preeclampsia
       3. Maternal physiologic alterations induced by preeclampsia
       4. Distinguish between preeclampsia and eclampsia
           a. seizure prophylaxis with magnesium sulfate
           b. the toxic effects of magnesium therapy and the maternal
               serum levels of magnesium associated with each
       5. Treatment of hypertension during preeclampsia
       6. Potential risks of and benefits of epidural analgesia in preeclamptic
           patients
       7. Potential risks of the induction of general anesthesia in the
           preeclamptic patients.
   D. Obstetrical hemorrhage
       1. Pregnancy-induced changes in coagulation
       2. Disseminated intravascular coagulation
       3. Potential hematologic alterations induced by:
           a. abruptio placenta
           b. preeclampsia
           c. fetal death-in-utero
           d. amniotic fluid embolus
       4. Management of DIC
   E. Risks and benefits of epidural anesthesia in parturients with
       valvular heart disease
       1. Mitral stenosis
       2. Aortic stenosis
       3. Mitral regurgitation
       4. Aortic regurgitation
       5. IHSS
   F. Advantages and disadvantages of epidural anesthesia in the parturient
       with severe asthma
   G. Management of the parturient with a neurologic disorder
       1. Seizure disorder
       2. Multiple sclerosis
       3. Myasthenia gravis
       4. Arterio-venous malformation
       5. Spinal cord injury
       6. Degenerative disc disease
       7. Scoliosis: with or without corrective surgery
       8. Peripheral neuropathy
   H. Significance of preterm labor
       1. Implications of regional and general anesthesia for the preterm fetus
       2. Tocolytic agents
           a. the most commonly used
           b. their pharmacology
           c. side effects
               i. effects on maternal glucose metabolism
               ii. effect on serum potassium levels
               iii. cardiovascular effects
                   1) maternal heart rate
                   2) maternal cardiac ischemia
                   3) pulmonary edema
               iv. anesthetic implications of maternal administration of
                   tocolytic agents
   I. Neonatal resuscitation
       1. Changes in neonatal circulation to allow the fetus to adapt
           to extra-uterine life
           a. Changes in the pulmonary and systemic circulation at birth
               i. Cause of physiologic closure of the ductus arteriosus and the
                   foramen ovale
               ii. Significance of failure of physiologic closure of these shunts
               iii. What factors may predispose the fetus to close these shunts
           b. Factors stimulating the initiation of respiration in the newborn
           c. Apgar Score
               i. initial assessment of the newborn
               ii. management of an infant that demonstrates respiratory
                   depression and bradycardia at birth
               iii. indications for intubation of the newborn infant
               iv. indications for chest compressions in the depressed infant
               v. use of epinephrine for newborn resuscitation and the possible
                   routes of administration
               vi. indications for volume replacement in the depressed neonate
           d. Management of the neonate stained with meconium
               i. when intubation is needed
               ii. when only suctioning is recommended

4. Anesthesia for labor and delivery.

   A. Non-pharmacologic techniques: advantages and disadvantages
       1. Psycho prophylaxis (prepared childbirth education)
       2. TENS
       3. Acupuncture
       4. Self-hypnosis
   B. Parenteral narcotic analgesia
       1. Advantages and disadvantages of IV narcotic administration
           a. meperidine
               i. risk of seizure
               ii. metabolite normeperidine
           b. fentanyl
           c. morphine sulfate
           d. agonist/antagonist narcotics: butorphanol and nalbuphene
       2. IV PCA administered narcotics for labor analgesia
   C. Inhalation analgesia
       1. N2O/O2 mixture
       2. Inhalation of halogenated agents
   D. Epidural and subarachnoid labor analgesia
       1. Advantages and disadvantages of neuraxial labor analgesia
           a. epidural
           b. spinal
           c. combined spinal/epidural
       2. Site of action of local anesthetics
           a. epidural space
           b. subarachnoid space
       3. Site of action of narcotics
           a. epidural space
           b. subarachnoid space
       4. Pharmacology of the anesthetics when administered into either the
           epidural or subarachnoid space
           a. bupivacaine
           b. levobupivacaine
           c. ropivacaine
           d. chloroprocaine
           e. meperidine (discuss the local anesthetic effects)
           f. fentanyl
           g. sufentanil
       5. Local anesthetic toxicity
           a. signs and symptoms of an intravenous injection of local anesthetic
           b. relative cardiac toxicity of local anesthetics, and the treatment
           c. CNS toxicity of local anesthetics and the management of resultant
                seizures
       6. Complications of an incidental dural puncture during placement of
           an epidural
           a. how to recognize a high spinal vs. total spinal anesthetic
               i. etiology of respiratory arrest with a total spinal anesthetic
               ii. why the pupil will be dilated after total spinal anesthesia
           b. diagnosis and management of dural puncture headache
               i. complications of epidural blood patch
               ii. prophylactic epidural blood patch
       7. Risk of neurologic injury after placement of a regional anesthetic.
           a. backache after regional anesthesia
           b. nerve root injury after epidural or spinal placement
           c. spinal cord injury after epidural or spinal anesthesia

5. Anesthesia for Cesarean Section

   A. Advantages and disadvantages of epidural, spinal or general
       anesthesia for cesarean section
   B. Local anesthetics, concentrations and doses, used for either epidural or
       spinal anesthesia for cesarean section
   C. Preparation of the pregnant patient for general anesthesia
       1. Impact of the GI changes in pregnancy on the risk of maternal
           aspiration of gastric contents after the induction of general
           anesthesia
       2. Technique of rapid sequence induction
           a. why this is necessary in the term pregnant patient
           b. rate of oxygen desaturation during a rapid sequence induction
               of GA in the pregnant patient
       3. Induction of general anesthesia
           a. advantages and disadvantages of specific induction agents
               i. Etomidate
               ii. Pentothal
               iii. Propofol
               iv. Ketamine
           b. induction dose of each
       4. Effects of regional vs. general anesthesia on uterine blood flow
       5. Appropriate anesthetic choices for emergency cesarean section,
          situations
           a. non-reassuring fetal heart rate tracing
           b. maternal hemorrhage
           c. double set up
   D. Techniques of postoperative analgesia after cesarean section
       1. Parenteral narcotics -- intermittent dosage or IV PCA
       2. Epidural narcotics: with or without local anesthetics
           a. preservative-free morphine
           b. epidural infusion of narcotics/local anesthetic solutions
       3. Subarachnoid narcotics
           a. preservative-free morphine
           b. other narcotics

6. Equipment necessary to care for the peripartum patient.

7. Care for the pregnant patient during the
   peripartum and/or perisurgical period.

   A. Perform an appropriate history and physical exam and order
       lab investigations when indicated
   B. Make an appropriate anesthetic plan
       1. Labor analgesia
           a. contraindications to the placement of a neuraxial block
           b. appropriate times to administer:
               i. epidural labor analgesia
               ii. spinal labor analgesia
               iii. combined epidural-spinal analgesia
               iv. intravenous narcotics
           c. appropriate maternal and fetal monitoring after placement of an
               epidural and/or spinal labor analgesic
       2. General anesthesia
           a. establish appropriate monitoring prior to the induction
               of general anesthesia
           b. choose an appropriate induction technique
       3. Complications of anesthetic interventions, such as:
           a. maternal hypotension
           b. high or total spinal
           c. failed or difficult intubation
           d. inadvertent dural puncture
           e. management of local anesthetic overdose or intravascular
                injection
               i. local anesthetic induced seizure
               ii. local anesthetic induced cardiac toxicity
               iii. inadequate anesthesia or analgesia
   C. Provide care for the newborn if needed, including neonatal
       resuscitation

Formal lectures administered on a monthly basis

1. Physiologic adaptation to pregnancy
2. Neonatal resuscitation
3. Anesthesia for toxemia
4. Obstetric hemorrhage
5. Complications of Obstetric Anesthesia
6. Fetal heart rate monitoring
7. Management of postdural puncture headache
8. Labor analgesic techniques: epidural vs. combined spinal-epidural
9. Local anesthetics