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Flashcards in OB I Deck (39)
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1

What makes a pregnancy high risk?

  • Hypertensive disorders
  • antepartum hemorrhage
  • diabetes, cardiac, renal, thyroid, neurologic disease, asthma, obesity, drug abuse
  • advanced maternal age
  • prematurity
  • multiple gestation
  • fetal malpresentation, placental abruption, compression of umbilical cord, intrauterine infections

2

What is the maternal mortality rate?

most frequent causes?

What are the anesthesia related complications?

  • Maternal mortality in US is 7.5 per 100,000 live births
    • pregnancy-induced HTN
    • hemorrhage
    • PE
  • Anesthesia related complications- accounted for 5.2% of maternal deaths
    • airway problems/aspiration
    • LA toxicity or high block

3

How is hypertension defined in pregnancy?

What can it cause?

  • 7-10% of all pregnancies are complicated by HTN
  • mild HTN >140/90 or a rise in SBP of 30 mmHg above baseline or rise in DBP of 15 over baseline
  • Severe HTN >160/110
  • HTN can cause:
    • abruptio placentae
    • DIC
    • hepatic failure
    • cerebral hemorrhage
    • others on separate card

4

What are the complications caused by hypertension during pregnancy?

Neurological

pulmonary

CV

  • Neurological
    • HA
    • visual disturbances
    • hyperexcitability
    • sz
    • intracranial hemorrhage
    • cerebral edema
  • Pulmonary
    • upper airway edema
    • pulmonary edema
  • CV
    • decreased intravascular volume
    • increased arteriolar resistance
    • heart failure

5

What are the complications caused by hypertension during pregnancy?

Hepatic

Renal

Hematological

 

  • Hepatic
    • impaired function
    • elevated enzymes
    • hematoma
    • rupture
  • Renal
    • proteinuria
    • Na retention
    • decreased GFR
    • renal failure
  • Hematological
    • coagulopathy
      • thrombocytopenia
      • platelet dysfunction
      • prolonged PPT?
    • DIC

6

How does maternal HTN during pregnancy affect the fetus?

Impaired uteroplacental perfusion

7

What conditions predispose a woman to pregnancy-induced hytension (PIH)?

  • Primaparity
  • maternal age >40
  • african american race
  • chronic HTN
  • chronic renal disease
  • Insulin-dependent diabetes
  • history of preeclampsia (maternal- familial)
  • Obesity
  • multiple gestation

8

What is preeclampsia?

What can it cause?

When does it return to normal?

  • Condition characterized by:
    • vasoconstriction
    • hypovolemia
    • coagulation abnormalities
    • poor organ perfusion
  • Defines as new onset HTN that occurs after the 20th week gestation with proteinuria
  • Can cause:
    • cerebral bleeds
    • pulmonary edema
    • hepatic rupture
    • HELLP syndrome
  • Returns to normal within 3 months after delivery

9

How is preeclampsia categorized (mild vs severe)?

  • Mild
    • HTN:
      • 140/90 or greater or
      • increase of 30 mmHg above systolic or
      • 15 above diastolic
    • Proteinuria: >500 mg/day
  • Severe
    • HTN:
      • 160/110 or greater
    • Proteinuria: 
      • >5 g/day and/or
      • oliguria (UOP < 500 ml/day)
      • evidence of severe end-organ damage
        • oliguria
        • cerebral disturbances
        • pulmonary edema
        • epigastric pain or impaired liver fxn
        • intrauterine growth retardation

10

What is Eclampsia?

When does it usually occur?

What are early manifestations?

Treatment?

  • Preeclampsia (HTN, edema, and proteinuria) with seizures
  • Life-threatening emergency
  • most common in 3rd trimester
  • Early CNS manifestations are HA and visual disturbances
  • Treatment:
    • Oxygen (ABC's)
    • LUD
    • IV access
    • Mag sulfate
    • antihypertensives
    • fluid balance
    • coag studies
    • fetal monitoring and resuscitation

11

How is preeclampsia treated?

  • Mainstay of therapy is to control HTN, prevent seizures, and deliver fetus
  • Treatment of maternal HTN (a-line)
    • goal is DBP <110
    • labetalol and hydralazine commonly used
    • other options Nitroglycerine or nifedipine
    • want to gradually decrease BP- may cause fetal distress to drop too quick
  • Seizure prophylaxis with Magnesium sulfate
  • Correct hypovolemia (hydration, foley)
  • Correct coagulation abnormalities
  • Correct acid/base and electrolyte abnormalities
  • assure fetal viability

12

How does Magnesium sulfate work?

  • drug of choice for hyperreflexia, prevention and control of sz related to preeclampsia and eclampsia
  • Causes relaxation of vascular, bronchial and uterine smooth muscle
  • decreases cerebral irritability and prevents/treats sz
  • mildly sedates
  • vasodilates (caution hypotension)
  • decreases uterine tone
  • potentiates the action of depolarizing and non depolarizing muscle relaxants
  • croses placenta and causes neonatal hypotonia and respiratory depression

13

What is the Magnesium sulfate dose?

What are the maternal side effects?

How can you reverse Magnesium sulfate?

  • Dose:
    • bolus 4 g IV over 10 minutes
    • maintenance: 1 6/hr IV infusion
  • Maternal side effects:
    • flushing
    • HA
    • dizziness
    • skeletal muscle weakness
    • deep tendon reflex depression
    • respiratory depression
    • pulmonary edema
  • **monitor serum levels for toxicity
  • Revers the effects of Mag sulfate by administering Calcium
    • Calcium gluconate 1 gm or calcium chloride 300 mg

14

How does magnesium therapy affect the anesthetic management?

  • It potentiates depolarizing and non-depolarizing neuromuscular blockers
    • Never administer defisiculating dose of NMB
    • Standardize dose of Sch to 1 mg/kg
    • Administer 1/2 to 1/3 maintenance dose of non-depolarizers
    • Dose by PNS
  • Mag sulfate antagonizes vasoconstrictive effects of alpha agonists, so ephedrine and phenylephrine are less effective

15

What are the key points in managing the anesthetic for a preeclamptic or eclamptic patient?

  • Assess sz control and neurologic status
  • assess airway
  • correct hypovolemia with colloid fluid bolus (250-500 ml)
  • control BP (DBP <100)
  • Consider A-line, CVP, SWAN
  • continuous FHR monitoring
  • oxygen to parturient
  • Lab workup:
    • CBC
    • renal profile
    • liver function tests
    • Pt/PTT
    • FDP- fibrin degredation products
    • FSP- fibrin split products
    • TEG
    • platelet count

16

Why is continuous epidural anesthesia preferrable for the preeclamptic or eclamptic patient?

What do you need to be careful of?

  • May improve maternal HTN and improve organ blood flow, uteroplacental perfusion and fetal oxygenation
  • Gradual onset of sympathetic block
    • CV stability
    • avoids neonatal depression
  • Avoids airway instrumentation
  • Careful with:
    • hypotension (esp SAB) and its affect on uteroplacental flow
    • Avoid regional if signs of increased ICP, coagulopathies or severe hypovolemia

17

Why can GA be dangerous in a preeclamptic or eclamptic patient?

  • exaggerated response to laryngoscopy and intubation 
  • more airway edema
  • avoid ketamine
  • exaggerated response to NDMR if on mag sulfate

18

What is HELLP syndrome?

  • A severe form of preeclampsia characterized by:
    • Hemolytic anemia
    • Elevated Liver enzymes
    • Low Platelet count
  • Ranges from mild self-limiting condition to multiorgan failure

19

What is the hallmark sign of HELLP syndrome?

When do they present?

What are the other symptoms?

  • Hallmark sign of HELLP is hemolysis (microangiopathic hemolytic anemia)
  • Most present preterm (20% postpartum)
  • Other signs and symptoms:
    • Malaise (90%)
    • epigastric pain (90%) ** most common initial symptom
    • N/V (50%)
    • Evidence of preeclampsia before delivery (80%)

20

What are the problems associated with vaginal delivery after C-section?

  • Incidence of uterine ruptuer 1%
  • Increase in uterine infections
  • risk of blood transfusions
  • risk of emergency c-sections

21

What is primary dysfunctional labor?

Treatment?

  • Failure of labor to progress normally d/t:
    • ineffective uterine contractions
    • arrest of cervix dilation
  • Treatment
    • oxytocin
    • may require anesthesia

22

What are the different breech presentations?

A. Complete

B. Incomplete

C. Frank

23

What is this position?

Transverse Lie position

24

How is Occiput posterior position different from normal position?

Occiput anterior (normal presentation) pictured here

Occiput posterior

25

What problems are multiple gestation pregnancies associated with?

  • Premature labor
  • abnormal fetal presentations
  • PIH
  • Increased risk of postpartum hemorrhage (uterine atony)
    • may require higher doses of oxytocin for uterus to contract
    • Do not start until all fetuses delivered
  • Increase anesthesia morbidity
    • prone to aortocaval compression
    • prone to hypoxia (greatly reduced FRC)
    • Risk high spinal/epidural blockade

26

Anesthesia for multiple gestations

Labor and delivery

twins

triplets (+)

  • Labor and delivery
    • continuous epidural analgesia/CSE
    • Constantly be prepared for emergency C/S
  • Twins
    • double "set up"
    • Sometimes GA is required to facilitate delivery of 2nd twin
  • Triplets +
    • C/S preferred route of delivery
    • epidural or spinal

27

What is preterm labor?

What determines survivability of the infant?

  • Preterm labor- regular uterine contractions that occur between 20-37 weeks of gestation that result in dilation or effacement of cervix
  • Survivability of infant depends on the maturity of major organs as well as gestational age/fetal size
  • Pre-term labor is leading cause of perinatal morbidity and mortality

28

What are the maternal risk factors for premature labor?

(15)

  • History of preterm delivery
  • young age (<18) or old age (>35)
  • low socioeconomic status
  • acute or chronic illness
  • trauma
  • abdominal surgery during pregnancy
  • infection (genital, UTI)
  • pyelonephritis
  • smoking 
  • drug use
  • obesity
  • multiple gestation
  • abnormal fetal presentation
  • low prepregnancy BMI
  • abnormal uterine/cervical anatomy

29

How is premature labor treated?

  • Bedrest
  • FHR monitoring
  • check for PROM
    • abx to prevent maternal chorioamnionitis
  • Progesterone therapy
  • Tocolytic agents (to suppress uterine activity)
    • CCB- Nifedipine
    • Prostaglandin inhibitors (NSAIDS- Indomethacin, ketorolac)
    • Beta-2 agonists
    • Mag sulfate
  • Corticosteroids for fetal lung development

30

What CCB is used to treat preterm labor?

What are the maternal side effects?

  • Nifedipine
  • Maternal side effects:
    • hypotension
    • flushing
    • HA
    • dizziness
    • nausea