OB II Flashcards Preview

Advanced Principles II > OB II > Flashcards

Flashcards in OB II Deck (28)
Loading flashcards...
1

What are the different types of placenta previa?

  • Implantation of placenta is too low and encroaches on cervical os- 0.4% of all pregnancies
  • Marginal placenta previa
    • placental edge is at the os but does not cover it
    • vaginal birth possible at discretion of OB/GYN
  • Partial placenta previa
    • part of internal cervical os is covered
    • mandates C/S
  • Complete placenta previa
    • complete internal cervical os is covered
    • mandates c/s

2

Who is at greatest risk for placenta previa?

How is it characterized?

  • Greatest risk factors:
    • prior c-section (uterine scarring)
    • increased maternal age
    • smoking
  • Characterized by painless vaginal bleeding d/t maternal separation
  • lower uterine segment lengthening and cervical dilation responsible for bleeding
  • Can be identified by ultrasound

3

Anesthetic management for placenta previa

  • Aggressive fluid resuscitation: blood products, colloid, crystalloid
  • frequent BP measurement (A-line)
  • FHR
  • foley
  • 2 large bore IVs
  • maternal O2 therapy
  • aspiration prophylaxis
  • For diagnosis: vaginal exam
    • may have sudden, severe bleeding, so have double set up in or- prepare for emergency c-section
  • If stable- regional
  • if brisk bleeding or unstable- GETA
    • RSI, ketamine or etomidate

4

What is abruptio placentae?

  • Premature separation of the placenta
    • baby is not being perfused
    • can have concealed hemorrhage, external hemorrhage, or external hemorrhage with prolapse of the cord
  • Jeopardizes fetal blood supply
  • Open venous sinuses in uterine wall may allow amniotic fluid in

5

What are the risk factors for abruptio placentae?

  • chronic hypertension or preeclampsia
  • trauma (lap seat belts or steering wheel)
  • cocaine abuse
  • cigarette smoking
  • increased parity
  • increased age
  • physical work
  • stress

6

What are the signs and symptoms of abruptio placentae?

  • moderate to severe abdominal pain
  • uterine irritibility/tenderness
  • vaginal bleeding
    • clotted, dark blood
    • may be underestimated because it is concealed behind the placenta
  • maternal hypotension
  • fetal bradycardia/distress
  • coagulopathies/DIC

7

What is the anesthetic management for Abruptio placentae?

for mild abruptions

for severe abruptions

  • Choose btw regional and GA based on:
    • urgency for delivery
    • maternal hemodynamic stability
    • coagulopathies
  • Mild to moderate abruptions
    • may have vaginal delivery but be prepared for emergency c/s
  • Severe abruptions- when placental separation is >50% (maternal mortality 1-3% and fetal 50%)
    • rapid response is imperative
    • crash emergency c/s- get help!
    • GETA/RSI with ketamine or etomidate, opioids
    • two large bore IVs
    • fluid resuscitation
    • 100% oxygen
    • a-line, CVP
    • blood products (PRBC, FFP, Cryo, plt)

8

What situations are associated with uterine rupture?

  • scar dehiscence from VBAC
  • overaggressive oxytocin use
  • uterine distension (multiparity)
  • scarred uterus
  • uterus manipulation
  • blunt trauma

9

What are the signs and symptoms of uterine rupture?

treatment

  • Sudden, severe, tearing abdominal pain
  • vaginal bleeding
  • maternal hypotension
  • absence of uterine pressure/cessation of labor
  • acute fetal bradycardia 
    • most reliable sign
    • fetal mortality 80%
  • Treatment
    • emergency c/s and laparotomy
    • GETA- prepare for large blood loss

10

What is placenta accreta?

  • abnormally adherent placenta to the uterus
  • placenta vera- adherence to the myometrium with invasion of or passage through uterine muscle
  • Placenta increta- invasion into the myometrium
  • placenta percreta- invasion through the myometrium into surrounding structures of the uterine serosa and pelvic structures

11

How are placenta accreta cases handled?

  • most cases will require c/s or cesarean hysterectomy
    • most common indication for obstetrical hysterectomy
  • Blood loss can be massive
  • volume resuscitation is crucial!
  • Get help!
    • GETA/RSI- etomidate, ketamine, opioids
    • 2 large bore IVs/a-line/CVP
    • blood products/fluid resuscitation
    • 100%FiO2

12

What is the leading cause of both early and delayed postpartum hemorrhage?

  • Retained placental fragments
  • in some cases, the uterus contracts but the placenta does not separate
  • in other cases, placenta appears to separate, but fragments of the placenta remain within the uterus

13

How is a retained placenta treated?

  • Therapy?
  • In some cases, the obstetrician requests uterine relaxation to facilitate manual removal 
    • IV nitroglycerin (1 mcg/kg bolus; 50-200 mcg bolus)
      • results in uterine relaxation by release of NO
    • GETA with high dose VA- provides anesthesia and uterine relaxation, but entails all the risks of GETA
    • Analgesia provided by pre-existing epidural or low dose ketamine

14

What is uterine inversion?

When should it be inspected?

What is first sign?

  • The uterine fundus inverts through the cervix into the vagina
  • rare, but potentially disastrous event during peripartum period
  • Inversion should be suspected in all cases of postpartum hemorrhage and hypotension.
  • First sign is hypotension

15

How is uterine inversion treated?

  • In some cases, uterine tone precludes immediate replacement and uterine relaxation is required
  • need rapid uterine relaxation with no side effects and a short duration of action to facilitate restoration of uterine tone after replacement
    • 200 mcg IV nitroglycerin 
    • GETA- halogenated VA are most proven method in relaxing the uterus
  • Once uterus is replaced, a firm well contracted uterus is required
    • fluid therapy
    • oxytocin (20-40 units/L) infused initially
    • 15-methyl prostaglandin F2-alpha may be required (0.25 mg IM/intrauterine)

16

What is uterine atony?

What causes it?

  • ineffective uterine muscle contraction
  • Causes
    • over distension of uterus in multiple gestation
    • high parity
    • prolonged labor
    • precipitous labor
    • augmented labor
    • tocolytics
    • high concentrations of halogenated anesthetics

17

How is uterine atony treated?

  • Drugs: Oxytocin, Ergot alkaloids, prostaglandins
  • ensure good IV access
  • fluid resuscitation
  • OB may try intrauterine balloon tamponade
  • may require transfusion and/or hysterectomy

18

What is amniotic fluid embolism?

mortality rate

when can it occur?

  • Amniotic fluid released into maternal circulation carries fetal debris and prostaglandins and leukotrienes--anaphylactoid picture
  • High mortality rate (60-80%)
    • accounts for 12% of all maternal deaths
    • high incidence (75%) among survivors have neurological deficit

19

What are the signs/symptoms of AFE?

  • maternal hypotension
  • maternal hypoxia
  • sz
  • pulmonary edema or ARDS
  • CV collapse with RV and LV failure
  • coagulopathies (DIC)
  • drop in end-tidal CO2
  • uterine atony
  • hypoperfusion of heart, lungs, kidneys which cause multi-organ failure
  • fetal distress

20

How is AFE treated?

  • Airway, breathing, circulation
  • Intubate, ventilate w/100% O2
  • Discontinue N2O
  • support circulation w/ basic CPR and vasoactive drugs and fluid resuscitation
  • A-line
  • LUD
  • consider early delivery of fetus
  • continue fetal monitoring
  • treat coagulopathies

21

What do you see in umbilical cord prolapse?

How is it treated?

  • Sudden fall in FHR
    • especially on rupturing the membranes
    • rapid fetal asphyxia
  • Can palpate umbilical cord on vaginal exam
  • Treatment:
    • t-berg
    • knee to chest
    • deliver immediately
    • manually push presenting part back into the uterine cavity
    • emergency c/s

22

What is significant of peripartum fever?

  • Risk of sepsis to both mother and neonate
    • can cause neonatal sz
    • can cause low APGAR scores
  • Clinical manifestation of chorioamnionitis
  • treated with antibiotic therapy

23

How is heart disease optimally managed?

  • Optimal management begins before conception
    • Consult with cardiologist and obstetrician to decide on best analgesic intervention
    • review NYHA classification (defines mortality risk level)
    • Determine exact cardiac lesion and tailor anesthetic plan accordingly
  • Early administration of analgesia
    • pain free labor to avoid catecholamines and increased SVR
    • regional is good
      • slow onset of epidural to avoid decreased SVR
      • pre-hydrate carefully
    • watch myocardial depressant drugs
  • Always provide supplemental oxygen
  • SBE prophylaxis

24

How does morbid obesity effect pregnancy?

  • Increased incidence of:
    • gestational diabetes
    • HTN
    • UTI
    • premature labor
    • low birth weight
    • fetal/neonatal demise
    • cephalopelvic disproportion
    • c-section
    • post partum hemorrhage
    • longer hospital stay

25

Anesthetic considerations for a morbidly obese parturient

  • establish IV early- may be difficult
  • establish epidural early- may be difficult with high failure rate
  • reduce volume of LA
  • expect difficult airway

26

What are the major problems encountered with diabetic parturients?

  • placental insufficiency
  • superimposed preeclampsia
  • diabetic nephropathy
  • diabetic ketoacidosis
    • main factor in maternal and fetal morbidity and mortality
    • ketones cross the placenta-->fetal hypoxia
    • neonatal risks:
      • increased premature labor
      • neonatal hypoglycemia
      • stillbirth
      • large babies

27

What should you consider when providing anesthesia to a parturient for a non obstetric surgery?

  • Maternal risk factors related to physiologic changes of pregnancy
  • teratogenisity of anesthetic agents
  • anesthesia's effects on uteroplacental blood flow
  • potential miscarriage/preterm labor and delivery
  • 3-8 weeks gestation most vulnerable time

28

Anesthetic plan for non obstetric surgery in parturient

  • Counsel about risk of preterm labor
  • perform good airway exam
  • minimize exposure to anesthetic agents
    • SAB, epidural; GA only if necessary
  • full stomach, RSI if after 12 weeks
  • positioning in 2nd and 3rd trimester- LUD
  • avoid hypotension and hyperventilation-- maintain uterine blood flow
  • avoid known teratogens especially in the first trimester- N2O and benzodiazepines
  • fetal heart rate monitoring postop