Obstetric Anesthesia Part 2: Hertz Flashcards
What are considered complicated pregnancies? (6)
Preterm labor
Premature rupture of membranes (PROM)
Chorioamnionitis
Umbilical cord prolapse
Amniotic fluid embolism
Partum hemorrhages
What defines premature labor?
Labor that occurs between 20-37 weeks gestation
Note: 8% of deliveries
What are the contributing factors to premature labor? (7)
Extremes of age
Inadequate prenatal care
Unusual body habitus
Increased physical activity
Infections
Prior preterm labor
Multiple gestations
Preterm infants under ______ weeks and weighing < ______grams have more complications.
30 weeks
1500 grams
What are breech premis at increased risk of?
Hypoxia and asphyxia
Note: picture of breeched baby.
What are complications relating to premature infants? (3)
- Inadequate surfactant before 35 weeks
- Soft, poorly calcified cranium predisposes to hemorrhage
- Many premature fetuses are in breech position
What is premature rupture of membranes (PROM)?
Leakage of amniotic fluid before onset of labor
What does the combination of PROM and preterm labor increase the risk of?
umbilical cord compression–>fetal hypoxemia
What are the predisposing factors causing the premature rupture of membranes? (6)
- Short cervix
- Hx of PROM or preterm labor
- Infection
- Multiple gestations (twins, triplets)
- Polyhydramnios (too much amniotic fluid)
- Smoking
What occurs within 24 hrs in 90% of PROM patients?
spontaneous labor
When is delivery indicated for PROM patients?
What drugs are indicated?
After 34 weeks of gestation
Otherwise, antibiotics and tocolytics given for 5-7 days
What is chorioamnionitis?
Infection of the chorionic and amnionic membranes which may involve the placenta, uterus, and umbilical cord.
What are the maternal complications from chorioamnionitis? (4)
- Dysfunctional labor–not contracting well
- Intraabdominal infection
- Septicemia
- Postpartum hemorrhage
What are the fetal complications of chorioamnionitis? (3)
- Acidosis
- Hypoxia
- Septicemia
What are the signs of chorioamnionitis? (4)
- Fever > 38ºC
- Maternal AND fetal tachycardia
- Foul smelling fluid
- Uterine tenderness
When is regional safe for a pt with chorioamnionitis? (3)
No signs of septicemia, thrombocytopenia, or coagulopathy.
Note: Pt will be on antibiotic therapy.
What is depicted?
umbilical cord prolapse
What are predisposing factors for this to occur? (5)
- Excessive cord length
- Baby in poor position
- Low birth weight
- Parity (births) > 5
- Rupture of membranes
How is this diagnosed? (3)
- Sudden fetal bradycardia
- Profound decelerations
- Confirmation by doctor
What is the treatment for this? (2)
- Immediate steep trendelenburg or knees to chest
- Push fetal part back into pelvis until stat c-section under general anesthesia
What is amniotic fluid embolism?
The entry of amniotic fluid into the mom’s circulation which occcurs through any break in uteroplacental membranes.
What is the incidence and mortality rate of amniotic fluid embolism?
low incidence
high mortality rate
What does amniotic fluid contain? (3)
- fetal debris
- leukotrienes
- prostaglandins
When is amniotic fluid embolism likely to occur? (4)
- Labor
- Delivery
- C-section
- Postpartum
Note: 50% of mortality in the 1st hour.
What is the classic triad of symptoms of amniotic fluid embolism?
- Hypoxemia
- Hypotension
- Coagulopathy
What are other symptoms of amniotic fluid embolism? (6)
Pulmonary edema
Cyanosis
CV arrest
DIC
Fetal distress
Seizures
What are 3 main characteristics that embody amniotic fluid embolism?
Pulmonary embolism
DIC
Atony of uterus
How do you treat amniotic fluid embolism? (2)
Aggressive CPR in supine position (do not tilt uterus)
Immediate c-section because quick delivery is better for baby and mom
What is placenta previa?
The placenta is abnormally placed and covers the cervix.
Identify the differing placenta previa categories.
List the type of previa that occurs from most to least frequently.
Low-lying or marginal (46%)
Complete (37%)
Partial (27%)
What are risk factor of placenta previa? (3)
Scarring of uterus from surgeries, pregnancies, ect
Multiple gestations
Abnormal uterus
What are the symptoms of placenta previa? (2)
PAINLESS vaginal bleeding
Episodic bleeding but severe hemorrhage can occur at any time
What is the management for placenta previa?
Less than 37 weeks, bedrest
After 37 weeks, c-section
Pts with a low-lying placenta must have a c-section. True or false?
False
May deliver vaginally if bleeding is mild.
All patients wiht vaginal bleeding are assumed to have placenta previa until proven otherwise. True or false?
True
U/S can localize placenta.
What is anesthesia type for unstable placenta previa pt>
Stat c-section with general anesthesia
What is needed for anesthesia for placenta previa pt?
Regional is considered in fluid loaded
2 large IVs
2 crossmatched blood units
Central line may be good option for rapid transfusion
What is depicted?
Placental abruption aka detachment
When does separation of the placenta normal occur with placenta abruption?
after 20 weeks
What is the danger of placental abruption?
Loss of area for maternal-fetal gas exchange leading to fetal distress
What is the most common cause of intrapartum fetal death?
placental abruption
What are risk factors of placental abruption? (7)
HTN
Trauma
Short umbilical cord
Multiple gestations
ROM
Drugs
Abnormal uterus
What are the symptoms of placental abruption? (4)
Painful bleeding
Uterine tenderness
Uterine activity increased
HTN is common, DIC possible
How is placenta abruption diagnosed? (2)
Ultrasound
Amniotic fluid is port wine colored
How is mild to moderate abruption treated?
Hospitalized
If > 37 weeks and no fetal distress, vaginal delivery
If fetal distress, c-section
What lab value will change as a result of mild to moderate abruption?
decreased fibrinogen, 150-250 mg/dL
What occurs to labs with severe abruption? (4)
Coagulopathy in 10% of cases
Fibrinogen < 150 due to active plasminogen
Platelets reduced
Factors 5 and 7 reduced
What are anesthetic considerations for severe abruption? (4)
C-section preferred to prevent further abruption
Aggressive fluid resuscitation to anticipate high blood loss
Vaginal bleeding may not reflect actual bleeding!
General preferred to treat hypovolemia
What is the incidence of uterine rupture and the causes? (5)
Rare
- Scar from previous surgery. Vertical scars bleed more.
- Forceps
- Prolonged labor
- Strong contractions
- Large, thin, weak uterus
What are the signs of uterine rupture? (5)
Fetal distress is most reliable sign
Frank hemorrhage
Cessation of labor, ineffective contractions
Abdominal pain that breaks through epidural
Constant pain with NO RELIEF BETWEEN CTX
How do you treat uterine rupture? (3)
Control bleeding by repairing arteries, etc
Volume rescuscitation
Immediate laparotomy under GETA
What situation will present with abrupt onset of continuous abdominal pain and hypotension even with an epidural?
uterine rupture
What occurs with a retained placenta?
The uterus cannot contract properly and continues to bleed.
Nitroglycerine must not be used when there is a retained placenta. True or false?
False, may be useful in relaxing the uterus.
What is placenta accreta?
abnormally adherent placenta
Label
List occurrence of placenta accreta from most to least.
Accreta (78%)
Increta (17%)
Percreta (5%)
What is the adherence to myometrium without invasion of or passage through the uterine muscle?
placenta accreta
What is the placental invasion of the myometrium?
increta
What is the invasion of the uterine serosa or other pelvic structures?
percreta, which can also invade the bladder and bowel
What are the risk factors for placenta accreta? (2)
Hx of placenta previa
Previous c-section
What is the treatment for placenta accreta?
uterine curretage, then oversewing the bleeding placenta bed but not usually successful
most cases require postpartum hysterectomy
What is the anesthetic treatment for placenta accreta? (3)
c/s or lap stat under general
blood rescusitate
coagulopathy correction
What is the major cause of postpartum hemorrhage?
uterine atony, which is usually accompanied by retained placenta
What is the treatment for uterine atony? (3)
Oxytocin
Metherigine (methylergonovine maleate)
Carboprost, Hemabate (Prostaglandin F2Alpha )
Where does oxytocin have an effect?
Uterus contractions
Mammary glands stimulates contraction of myoepithelial cells for milking
Smooth muscle when given in large doses resulting in decreased BP
What is the postpartum dose of oxytocin?
20 units in 1000ml LR
Infusion: 20-40 mU/min
What are the side effects of oxytocin? (2)
HYPOTENSION
N/V
What is methylergonovine maleate (Methergine)? (3 points)
Acts directly on smooth muscle of the uterus via alpha receptors
Increases tone, rate of contractions
Raises BP and CVP
What is the dosage of methergonovine maleate (Methergine)?
IM: 0.2 mg or
IV: 0.02 mg increments
What should you consider when giving methylergonovine maleate (Methergine)? (3)
Use cautiously in pts with HTN or cardiac disease
Caution in ASTHMA pts!
May produce severe HTN, CVAs and retinal detachment
What is prostaglandine F2alpha (Carboprost, Hemabate)?
Synthetic prostaglandin
Stimulates smooth muscle for contracting the uterus
What is the dose of Carbaprost, Hemabate?
IM: 250 mcg q 15-90 min as needed
Max dose: 2 mg
What is a contraindication of prostaglandin F2alpha (Carbaprost, Hemabate)?
ASTHMA
What drugs do you administer for uterine inversion?
NTG
Sevo
Helps relax the uterus to put things back inside.
What causes partum hemorrhages? (6)
- Placenta previa
- Placental abruption
- Uterine rupture
- Placenta retained
- Placenta accreta
- Uterine atony
Do the following cause pain?
placenta previa
placental abruption
uterine rupture
retained placenta
placenta accreta
uterine atony
The only ones that cause pain are:
- Placental abruption
- Uterine rupture
What can result in potentially massive blood loss?
Placenta previa
Placenta accreta
What may conceal bleeding?
Placental abruption
Uterine rupture
In what situation may the FHR disappear?
Uterine rupture
What are causes of hemorrhages:
antepartum
peripartum
postpartum?
Antepartum–placenta previa, abruption PA
Peripartum–uterine rupture U
Post partum–placeneta accreta, uterine atony PU
