Week 13 - OB Complications Flashcards
What are the risk factors for preeclampsia and eclampsia?
- Primigravida
- Chronic HTN
- Diabetes (pre-existing or gestational)
- Obesity
- Family history of preeclampsia
- Multiple gestation
- Use of assisted reproductive technology
- Homozygous angiotensin T-235
- Chronic renal disease
- Antiphospholipid syndrome
- > 40 years old
- African American race
What is preeclampsia?
- Starts with an issue related to the utero-placental interface
- The uterine spiral arteries don’t form correctly which leads to placental hypoxia
- This leads to an increase in cytokines and inflammatory factors
What are the signs and symptoms of preeclampsia?
Hypertension: SBP >140 or DBP >90 occurring after 20 weeks gestation or in early postpartum (returns to normal within 3 months of delivery)
Proteinuria: >300 mg/24 hrs confirms but is not necessary to diagnose preeclampsia
In the absence of proteinuria, what is needed for preeclampsia to be diagnosed?
One of the Following:
- Thrombocytopenia (platelet count <100,000)
- Renal insufficiency (Cr >1.1 or doubling of Cr absent other renal disease)
- Impaired liver function (elevated labs, LFT 2x normal)
- Cerebral disturbances (headaches w/ hyperreflexia or visual disturbances)
- Pulmonary edema or cyanosis
The imbalance of what two mediators is associated with preclampsia?
Prostacyclin and Thromboxane
What are the airway clinical features of preeclampsia?
Possibly upper airway edema
Pulmonary edema in 3% of pts due to:
- high LAP and PCWP
- low plasma colloid and osmotic pressure
- increased capillary permeability
What are the cardiovascular clinical features of preeclampsia?
Clinical features are varied:
- Hyperdynamic circulation – high CO, normal to increased SVR, normal or slightly decreased blood volume and preload
- Normal CO, lower preload, increased SVR
- Highly increased SVR, decreased blood volume and preload
What are the renal clinical features of preeclampsia?
- Increased uric acid due to decreased excretion
- Acute renal failure rare but possible
- Beware of HELLP syndrome (increased renal and hepatic failure)
What is HELLP Syndrome?
Hemolysis, Elevated Liver enzymes, and Low Platelets
-mild self limiting to fulminant causing multiple organ failure
What are the lab values to diagnose HELLP syndrome?
Hemolysis: abnormal peripheral blood smear and increased bilirubin level
Elevated Liver Enzymes: AST >70, LDH >600
Low Platelet Count: <100,000 (assuming no other coagulation issues)
How do you treat preeclampsia?
Definitive Treatment = Delivery of fetus
- Control HTN: hydralazine vs labetalol; NTG, Nifedipine, Esmolol
- Prevent seizures: magnesium is drug of choice to prevent eclampsia and seizures
What is the anesthetic management for preeclampsia?
- Detailed pre-op focused on severity of case: airway, fluid status, BP control, CBC, renal profile, LFTs, Coags IF abnormality suspected, platelet count needed before neuraxial block
- Epidurals preferred for preeclampsia: gradual onset of blockade, CV stability and avoidance of fetal distress, reduce airway challenges
What are the comorbidities for obesity and pregnancy?
- Gestational DM
- Preeclampsia
- Thromboembolic disease
- Wound infections
- C section
- Adverse neonatal outcome
- Increased surgical and anesthesia risk
- Increased risk for postpartum hemorrhage
- Magnifies pregnancy induced physiologic changes (FRC, GERD, Aortocaval compression, etc)
What are regional anesthetic considerations for obesity and pregnancy?
- Increased difficulty
- Recommend early epidural placement to ensure functioning catheter in case of C-section
- Greater use of continuous SAB catheters (decreased incidence of PDPH – decreased amount of dural punctures)
- Reduced dose of LA – avoid high spinal (decreased CSF volume w/ increased abdominal pressure pushes drug higher)
Why is there increased mortality with general anesthesia in obesity and pregnancy?
- Rapid desaturation
- Increased risk of regurgitation and aspiration
- Difficult mask ventilation
- Difficult OET
- Difficult ventilation
- Difficult positioning
- Prolonged operation
*why we try to do regional anesthesia when we can
What are the causes of obstetrical bleeding during the peripartum period?
- Placenta Previa (22% incidence of 3rd trimester bleeding) – occurs when placenta lies near the base of the uterus or across the cervix
- Abruptio Placenta (31% incidence of 3rd trimester bleeding) – premature separation of normally implanted placenta after 20 weeks and before delivery
- Placenta Accreta – accreta = onto myometrium, increta = into myometrium, precreta = through myometrium
What are the causes of obstetrical bleeding during the postpartum period?
– Uterine atony – Retained placenta – Vaginal Laceration – Uterine rupture – Uterine Inversion
What are the differential diagnoses of 3rd trimester bleeding?
- Placenta Previa = painless vaginal bleeding, maybe or may not fetal distress
- Abruptio Placenta = painful concealed bleeding, possible S&S of shock, probable fetal distress, possible coagulopathy
- Uterine Rupture = SEVERE abdominal pain, likely S&S of shock, absent fetal heart tones
What is placenta previa and its hallmark sign?
Placenta is lateral, near, or across the os (normal placenta is at the top of the uterus)
- With contraction, the placenta can be torn from the wall of the uterus
- Hallmark is PAINLESS vaginal bleeding during 2nd or 3rd trimester
- 5% of pregnancies at 4 months
- Diagnosed with ultrasound
What are the risk factors of placenta previa?
Prior c-section or uterine surgery
Smoking
Multiparous
DM (large placentas)
How common are each type of placenta previa?
Total Previa = 40%
Partial Previa = 30%
Marginal and Low Lying = 30%
What is the anesthetic management for placenta previa?
- Early eval and discuss options with mother – regional anesthesia is preferred (typically epidural)
- OR set up in case of emergent c-section if bleeding becomes uncontrollable during vaginal delivery
*Depends on location of previa, amount of bleeding, and delivery expectation
What is Abruptio Placenta? What are the signs and symptoms
Placenta separates from decidua before delivery of the fetus
-fetal distress occurs due to loss of area for maternal-fetal gas exchange
Usually presents with PAINFUL vaginal bleeding (beware, uterus can hold 2500+ cc of blood with minimal external bleeding)
-shock, DIC, ARF, fetal demise due to hypoxia
What are the risk factors of abruptio placenta?
HTN Increased age Multiparity Smoking Cocaine Trauma Premature rupture of membranes
What is the anesthetic management for abruptio placenta?
Frequently requires emergent GA, RSI, C-section, aggressive volume resuscitation, and ICU stay
- GETA, A-line, +/- CVC
- 2 large bore IVs
- Baseline Hct, coags, type & screen
- Monitor for DIC (occurs in 30% of cases when fetal demise)
- Deliver fetus and placenta
- Replace maternal intravascular volume, correct coagulopathy
What is Placenta Accreta?
Abnormally adherent placenta:
- accreta = adherence to myometrium (76%)
- increta = invasion into myometrium (18%)
- percreta = through myometrium into serosa and other pelvic structures (6%)
- prior uterine trauma, prior c-section, and current previa are suspicious for accreta
- can be diagnosed with ultrasound prior to delivery
- may perform arterial embolization of some vessels to reduce blood loss
- potential massive EBL indicates possible use of cell saver
What is the anesthetic management for placenta accreta?
GETA preferred as hysterectomy is likely as soon as the fetus is delivered (most common indication for postpartum hysterectomy in the US)
Regional technique is possible but not popular (pt discomfort, operating conditions, timing of removal of catheter, potential for DIC)
What is the most common cause of postpartum hemorrhage?
Uterine Atony
-can occur immediately or late postpartum
