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)
16
Q
What is uterine atony?
What causes it?
A
- 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
Q
How is uterine atony treated?
A
- Drugs: Oxytocin, Ergot alkaloids, prostaglandins
- ensure good IV access
- fluid resuscitation
- OB may try intrauterine balloon tamponade
- may require transfusion and/or hysterectomy
18
Q
What is amniotic fluid embolism?
mortality rate
when can it occur?
A
- 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
Q
What are the signs/symptoms of AFE?
A
- 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
Q
How is AFE treated?
A
- 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
Q
What do you see in umbilical cord prolapse?
How is it treated?
A
- 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
Q
What is significant of peripartum fever?
A
- 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
Q
How is heart disease optimally managed?
A
- 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
Q
How does morbid obesity effect pregnancy?
A
- 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
Q
Anesthetic considerations for a morbidly obese parturient
A
- establish IV early- may be difficult
- establish epidural early- may be difficult with high failure rate
- reduce volume of LA
- expect difficult airway
26
Q
What are the major problems encountered with diabetic parturients?
A
- 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
Q
What should you consider when providing anesthesia to a parturient for a non obstetric surgery?
A
- 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
Q
Anesthetic plan for non obstetric surgery in parturient
A
- 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
