OB II Flashcards
1
Q
What are the different types of placenta previa?
A
- 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
Q
Who is at greatest risk for placenta previa?
How is it characterized?
A
- 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
Q
Anesthetic management for placenta previa
A
- 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
Q
What is abruptio placentae?
A
- 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
Q
What are the risk factors for abruptio placentae?
A
- chronic hypertension or preeclampsia
- trauma (lap seat belts or steering wheel)
- cocaine abuse
- cigarette smoking
- increased parity
- increased age
- physical work
- stress
6
Q
What are the signs and symptoms of abruptio placentae?
A
- 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
Q
What is the anesthetic management for Abruptio placentae?
for mild abruptions
for severe abruptions
A
- 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
Q
What situations are associated with uterine rupture?
A
- scar dehiscence from VBAC
- overaggressive oxytocin use
- uterine distension (multiparity)
- scarred uterus
- uterus manipulation
- blunt trauma
9
Q
What are the signs and symptoms of uterine rupture?
treatment
A
- 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
Q
What is placenta accreta?
A
- 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
Q
How are placenta accreta cases handled?
A
- 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
Q
What is the leading cause of both early and delayed postpartum hemorrhage?
A
- 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
Q
How is a retained placenta treated?
A
- 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
- IV nitroglycerin (1 mcg/kg bolus; 50-200 mcg bolus)
14
Q
What is uterine inversion?
When should it be inspected?
What is first sign?
A
- 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
Q
How is uterine inversion treated?
A
- 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)
