Obstetric Hemorrhage Flashcards
By the 30th week of pregnancy, what is the expansion in blood volume?
40%
What is the significance of the increase blood in pregnancy?
large blood losses can occur w/o clinical evidence
What Is the normal blood loss with a SVD? C/s?
- SVD = 500ml
- C/S = 1000ml
What is the initial change that is used to maintain bp with hemorrhage?
Increased TPR
After what percent of blood loss is there a fall in CO such that SVR can no longer maintain BP?
20%
How do BP and CO decrease in relation to one another?
in parallel to each other
What is placental abruption?
Premature separation of the normally implanted placenta from the uterus
What is the clinical triad of placental abruption?
- Painful Uterine bleeding
- Hypertonic uterus
- fetal distress/death
Inspection of the vagina with placental abruption shows what?
Adherent retroplacental clot with depression of the the underlying placental tissue
What is a grade I placental abruption? (-vaginal bleeding -Uterine s/sx -maternal BP -maternal fibrinogen -FHT)?
- Slight vaginal bleeding
- Uterine irritability
- Unaffected BP
- normal fibrinogen
- FHT normal
What is a grade II placental abruption? (-vaginal bleeding -Uterine s/sx -maternal BP -maternal fibrinogen -FHT)?
- Mild to moderate uterine bleeding
- Uterine irritable, tetanic, or frequent ctx
- BP maintained, but orthostatic
- Tachycardia
- Fibrinogen decreased
- FHT show distress
What is a grade III placental abruption? (-vaginal bleeding -Uterine s/sx -maternal BP -maternal fibrinogen -FHT)?
- Moderate to severe bleeding
- Uterine tetanic and painful
- Hypotension
- Fetal death
- Fibrinogen less than 150
- Coag abnormalities
What percent of placental abruption occurs before the onset of labor?
80%
What is the etiology of placental abruption? (5)
- Cocaine use
- maternal smoking
- poor nutrition
- trauma
- maternal HTN
What is the hallmark presentation of placental abruption?
Painful bleeding in the 3rd trimester
True or false: placental abruption rarely occurs more than once
False– significant rate of recurrence (5-17%)
What is the treatment for a grade I placental abruption?
-Observe
What is the treatment for a grade II or more placental abruption?
- Continuous fetal monitoring
- Tocolysis (?)
- Delivery
- volume resuscitation
What is placenta previa?
Implantation of the placenta over the cervical os
What are the three variations of placenta previa?
- Total
- Partial
- Marginal
What type of placenta previa is the worst? What fraction of previas are these?
Total
30% ish are these
What is the complication of partial placenta previa?
Dilation causes detachment
What is a marginal previa?
Placenta encroaches a bit onto the os
How do you differentiated between marginal and partial placenta previa?
US and the degree of cervical dilation and method of diagnosis
What is the leading cause of third-trimester hemorrhage?
Placenta previa
What is the classic presentation of placenta previa?
painless vaginal bleeding
What are the three major risk factors for placenta previa?
- Advanced maternal age
- Minority
- Previous C-section
Why are previous cesarean deliveries a risk for placenta previa?
implantation can get caught in the irregular scarred area
When are most placenta previas found, when they are? Why?
2nd trimester d/t anatomy scan
When is vaginal delivery appropriate for placenta previa? Why should be done for this?
if marginal previa
Do double set up
If you diagnose placenta previa a long time from delivery, what should you do?
Expectant management with avoidance of sexual intercourse d/t contraction induction
What are accreta, increta, and percreta?
- Accreta = attachment onto the myometrium
- Increta = invades the myometrium
- Percreta = penetrates the myometrium
What is the decidua basalis?
the area of endometrium between the implanted chorionic sac and the myometrium, which develops into the maternal part of the placenta
What is abnormal placentation?
formation of an abnormally firm attachment to the uterine wall with loss of the deciruda basalis and incomplete development of the fibrinoid layer
What is the incidence of abnormal placentation with previa without prior surgery? WIth precios c/s with multiple c/s?
W/o = 4%
with 1 = 10-35%
with multiple = 60-65%
How long does the bleeding last for with placenta previa? Placental abruption?
Previa = Stops within 2 hours
Abruption, Continuous bleeding
Which presents with painful bleeding: Placenta previa/abruption? Painless?
Painful = Abruption Painless = Previa
What happens to FHT with placenta previa? Placental abruption?
Normal with previa
Variable with abruptio
Which commonly has coagulation defects: placenta previa or placental abruption?
Abruption has coagulation defects
Previa does not
What is vasa previa?
Fetal vessels traverse the membranes and cover the os
What is the classic presentation of vasa previa?
SROM, laceration of the fetal vessel, and rapid fetal death
What is the the fetal mortality rate with vasa previa?
more than 50%
Effective hemostasis after separation of the placenta is dependent on what?
The myometrium to compress the vessels
Failure of the myometrium to compress the myometrial vessels is usually attributed to what?
Myometrial dysfunction or retained POS
What are the risk factors for myometrial dysfunction? (3)
Overdistention of the uterus 2/2:
- Multiple gestations
- Polyhydramnios
- Fetal macrosomia
How do you prevent or minimize PP hemorrhage?
Establish IV access just prior to labor, and prep for possible blood transfusion
Why do you want to avoid excessive traction on the umbilical cord during delivery?
possibility of hemorrhage
How do you manage hemorrhage PP?
Continue oxytocin/prostaglandins
-Frequently palpate fundus and monitor VS
How is misoprostol administered to treat PP hemorrhage?
PR
1 unit of pRBC increase HCT and Hb by what? 1 unit of platelets?
- pRBCs = 3% and 1g
- Platelets = 5000-10000
What is a first degree vaginal laceration?
vaginal mucosa and perineal skin
What is a second degree vaginal laceration?
Also includes the muscles of the perineal body.
What is a third degree vaginal laceration?
Also include the anal sphincter
What is a fourth degree vaginal laceration?
Extends through rectal mucosa
What are the three major pelvic hematomas?
- Vulvar
- Vaginal
- Retroperitoneal
What is a vulvar hematoma? Are these painful or painless?
Laceration of vessel in superficial fascia of anterior or posterior pelvic triangle
Painful
What is the treatment for a vulvar hematoma?
Volume support
-incise and evacuate clost
What causes vaginal hematomas?
Results from trauma to soft tissues during delivery, causing blood to accumulate in the plane above the pelvic diaphragm
What are the s/sx of vaginal hematoma?
Severe rectal pain or feels like she still has to push
How do you treat vaginal hematomas?
Take to OR, I+D, pack
What causes a retroperitoneal hematoma?
Laceration of a vessel originating from the hypogastric artery, and can dissect up to the renal vasculature
How do you detect a retroperitoneal hematoma?
Uterus will be displaced d/t hematoma, and s/sx of shock
What is the treatment for a retroperitoneal hematoma?
- Surgical excision
- ligation of hypogastric vessels
True or false: A previous oxytocin-stimulated labor is a risk factor for the development of myometrial dysfunction
True
True or false: Prolonged or rapid labor is a risk factor for myometrial dysfunction
True
What are the two ethnicities that have an increased risk for postpartum hemorrhage?
Asians
Hispanics
Cryoprecipitate replaces which coagulation factors? What else?
8 and 12
Fibrinogen
Fresh frozen plasma replaces which coagulation factors?
5, 8, and antithrombin III
What is a succenturiate lobe? What is the significance of this?
- Accessory lobe of the placenta
- Increases the risk of leaving behind part of the placenta after delivery
