Third trimester bleeding

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Third trimester bleeding

• Tom Archer, MD, MBA
• UCSD Anesthesia

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Death in pregnancy

• Pulmonary thromboembolism (clotting tendency in
  pregnancy)
• Ante and postpartum hemorrhage (1 cause in poor
  countries)
• Hypertensive disorders / pre-E / CVA

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Third trimester bleeding-- antepartum

• Placental abruption (1 / 100 pregnancies)
• Placenta previa (1 / 200 pregnancies)
• Uterine rupture (classical scar, VBAC with LTCS)
• Vasa previa (1 / 2000 pregnancies)

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Increased blood volume

• Normal delivery transfusion usually unnecessary,
  despite 500-1000cc blood loss.
• Dangers of transfusion
• Infection
• Immune modulation (CA, other bad things?)

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Mechanisms of hemostasis in OB

• Uterine contraction!
• Platelet plug
• Vasoconstriction
• Fibrin formation and cross linking (Factor XIII)
• Fibrous tissue formation

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Hemostasis
A Under physiologic conditions, hemostasis is
prevented by the endothelium. This provides a
physical barrier and secretes platelet inhibitory
products, such as prostacycline (PGI2) and nitric
oxide (NO).B With endothelial cell injury,
platelets adhere to vWf in the subendothelium via
the platelet membrane receptor GPIb-IX.C This
adhesion activates platelets, causing a shape
change and the release reaction (ADP is released,
which is a platelet agonist). The platelet
membrane intergrin receptor, GPIIb-IIIa, is
activated. Fibrinogen binds to this receptor,
effectively crosslinking platelets to form a
platelet plug. During platelet activation,
thromboxane A2 is formed from hydrolysis of
phospholipids (especially phosphatidylcholine) in
the platelet membrane. This is an important
platelet agonist, recruiting other platelets and
activating them, thus promoting aggregation. In
addition, phosphatidylserine (a phospholipid) is
moved to the outer layer of the platelet
membrane. Phosphatidylserine (which used to be
called PF3 or platelet procoagulant activity)
provides an essential binding site for activated
coagulation factors (especially for the tenase
and prothrombinase complexes), optimizing
activation of the coagulation cascade and the
formation of fibrin.D Fibrin is incorporated
into the growing platelet plug to form a stable
thrombus.
www.diaglab.vet.cornell.edu/.../coags/primim.htm
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Placental abruption

• Risk factors smoking, cocaine, hypertension,
  advanced age and parity, trauma, PROM (all cause
  arteriolar damage)
• Associated with IUGR / SGA (chronic placental
  malfunction, like previa).
• Vaginal bleeding, uterine tenderness and pain and
  uterine contractions.

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)
Placental abruption fetal asphyxiation (O2
supply is cut off).
Umbilical artery (UA)
Umbilical vein (UV)
Abruption
Uterine arteries
Uterine veins
Archer TL 2006 unpublished
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Placental abruption with trauma
Placenta shears off
Liquid placenta
Elastic myometrium
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Millers Anesthesia chap. 58
Occult hemorrhage in abruption
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Placental abruption

• Abruption is most common cause of DIC in
  pregnancy.
• 10 of abruptions show DIC.

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Obstetric management of placental abruption

• If fetus premature, FHTs OK and bleeding minimal
  ? expectant management in hospital?
• Otherwise, prompt / immediate delivery.

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Placenta previa

• Implantation in scarred area, frequently lower
  uterine segment.
• Painless vaginal bleeding
• Ultrasound mainstay of Dx
• Avoid vaginal exam. Double set-up.

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Placenta previa
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Placenta previa

• Premature labor is common.
• IUGR is common (crummy placentation site with
  poor nutrient transfer?)
• Steroid Rx for prematurity.
• Tocolysis or not?

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Placenta previa

• Risks are
• Profound hemorrhage
• Prematurity
• Goal is to delay delivery until fetus matures.
• Expectant management in hospital (at home, if
  close?).

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Actively bleeding previa or abruption

• General anesthesia
• Induce with ketamine or etomidate, not propofol
  or pentothal.
• Blood in OR

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Anesthesia for previa and abruption

• Spinal / epidural OK, IF patient is
• Not actively bleeding
• Normovolemic
• Platelet count and PT / PTT are OK
• Nevertheless, increased risk of heavy bleeding?
• LUS doesnt contract well
• ? Accreta
• ? Cut through placenta
• DIC may accompany abruption

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Vasa previa hemorrhage is fetal blood. Fetal
death very common.
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Uterine rupture

• Classical vertical uterine scar most vulnerable.
• Commonest cause is scar dehiscence
• With or without bleeding
• High index of suspicion and watch FHTs.
• Not always painful (esp. with LEA)

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Third trimester bleeding-- postpartum

• Uterine atony
• Genital tract trauma
• Retained placenta
• Placenta accreta
• Uterine inversion

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Uterine atony

• Commonest cause of postpartum hemorrhage.
• Contraction of uterus is primary hemostatic
  mechanism to stop postpartum bleeding.
• Overdistention of uterus is commonest case of
  atony.

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Uterine atony

• Overdistention
• Multiple gestation
• Polyhydramnios
• Macrosomia
• High parity
• Prolonged labor (tired uterus)

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Uterine atony

• Other causes of atony
• Chorioamnionitis
• Tocolytics
• Volatile anesthetic agents

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Uterine atony-- management

• Uterotonics
• Oxytocin
• Ergots (Methylergonovine)
• Prostaglandins (Carboprost, Hemabate)
• Misoprostol (usually for cervical ripening)

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Uterine atony-- oxytocin

• First-line, routine uterotonic.
• From posterior pituitary released by nipple
  stimulation (breast feeding)
• Older preparations from animals with ADH mixed
  in? water retention.
• Oxytocin has some ADH activity. Dont give with
  hypotonic solutions (e.g. D51/2NS).
• Oxytocin relaxes arteriolar and venous smooth
  muscle ? HYPOTENSION. No big boluses!

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Flor P. XXXX4756 25 yo repeat C/S with Hx of
peripartum cardiomyopathy 4 years before,
resolved. Fatigued during pregnancy, with normal
echoes. Epidural anesthesia for C/S 5/30/2007.
C/S Delivery
Phenylephrine
Oxytocin
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Uterine atony-- Carboprost

• Second-line drug?
• Contracts uterine smooth muscle but also
  bronchial and intestinal smooth muscle.
• Dont use in patients with asthma / COPD.
• May cause bowel movement / diarrhea on OR table.
• Very effective.

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Uterine atony-- Methergine

• Third line drug?
• Ergot alkaloids (ergotism, LSD)
• Can cause hypertension, pulmonary hypertension,
  NV, coronary vasospasm.
• Avoid combining pressors Methergine?
• Rarely if ever IV (0.02 mg slowly?)

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Ergotism, caused by mycotoxins in rye, called
St. Anthonys Fire in Middle Ages.
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Gangrene in livestock due to ergotism (mycotoxins
in grain feed)
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Postpartum hemorrhagegenital tract trauma

• Suspect in vaginal bleeding despite firm uterus.
• Dont confuse DIC with suture deficit.
• Cervical or vaginal laceration.
• More common with forceps or vacuum extraction.
• Will need exam under anesthesia.

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Postpartum hemorrhageRetained placenta

• Uterus cant fully contract
• Retained placenta needs to come out.
• Uterine relaxation does not anesthesia.
• Which does OB need?
• Uterine relaxation ? NTG or GA with volatiles.
• Anesthesia (SAB) may be enough.
• Beware of SAB or epidural hypovolemia.

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Postpartum hemorrhagePlacenta accreta
An ill-defined area of the placental/myometrial
junction was seen on the right lateral aspect of
the placenta (arrow). This was in vicinity of
prior myomectomy. At C-section, a 3 cm region of
placenta accreta was found.
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Postpartum hemorrhagePlacenta accreta

• Remember with repeat C/S and previa, think
  accreta.
• If accreta, think cesarean hysterectomy and big
  blood loss.

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Postpartum hemorrhageUterine inversion

• Rare (1 / 5000).
• Bloody mass in vagina
• Excessive traction on umbilical cord
• Excessive fundal pressure
• Anesthesia /- uterine relaxation. GA?

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Postpartum hemorrhageAdvanced options

• Angiographic arterial embolization
• Balloon occlusion of uterine arteries
• Balloon tamponade of uterine cavity
• Surgical artery ligation
• Hysterectomy.

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Transfusion Therapy

• Evolving idea of risks of homologous transfusion
• Infection
• Incompatibility reaction
• Immune modulation
• Patients dont do as well?
• Autologous transfusion
• Antepartum donation
• Intraoperative blood salvage (Cellsaver)
• Acute Normovolemic Hemodilution

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Transfusion Therapy

• Massive blood loss
• Can cause coagulopathy d/t dilution
• Dilutional coagulopathy
• Do platelets and clotting factors disappear
  together? 1PRBC/1 platelet/1 FFP?
• This is the new teaching.
• Old teaching was that platelets went first.

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Dilutional coagulopathy

• Old teaching
• Dilutional thrombocytopenia is first to develop
  (after 1 blood volume)
• Dilutional deficiency of clotting factors (after
  more than 1 blood volume)

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DIC

• Increased incidence with abruption, IUFD (after a
  week?, and rare), amniotic fluid embolus (rare,
  whatever it really is).
• Occurs early (before you would expect based on
  dilution)

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DIC

• Consumption of platelets and clotting factors.
• Diffuse oozing (venipuncture, IV sites)
• Low Plts and fibrinogen
• Prolonged PT / PTT

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Cryoprecipitate

• Fibrinogen
• von Willebrand Factor
• Factor 8
• Factor 13
• Fibronectin

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Universal preparations and Rx

• Do not confuse a suture deficit (surgical
  bleeding) with DIC.

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Evaluation of hemostasis

• When all else fails, talk with the patient!
• Hx best for chronic disorders.
• Examine patient and surgical field in acute
  disorder.
• Is problem dilutional (gradual and late) or DIC
  (earlier and fulminant)?

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Universal preparations and Rx

• Communication and awareness!
• OBs need to tell you.
• You need to be proactive, helpful and vigorous.
• Adequate IV access
• Type and crossmatch
• Might we need platelets, FFP, cryoprecipitate?
• Patient volume status
• Choice of anesthesia
• Advanced measures?
• Hysterectomy, arterial ligation or embolization,
  intracavitary balloon tamponade.

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Disaster management

• Call for help! Heroes call for help.
• Prioritize. Think ahead. Dont get behind. Dont
  yell.
• Crew resource management
• More IVs (avoid neck?)
• Arterial line
• Warm fluids and blood
• Early intubation (hypotension, nausea).
• Blood, platelets, FFP, cryo, Novo-Seven
• Get blood bank and hematologist involved early.

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The End