True Learn OB Flashcards
What proteins decrease in pregnancy? Which proteins increase in pregnancy?
Serum albumin concentration decreases during pregnancy because of plasma expansion. Many other serum constituents such as fibrinogen, transferrin, and globulins increase, most likely due to the hormonal changes secondary to the pregnant state.
What are the early signs of Amniotic Fluid Embolism?
What are the late signs of Amniotic Fluid Embolism?
What is the treatment for the baby?
Amniotic fluid embolism is characterized by an early stage with pulmonary vasospasm and right heart dysfunction or failure
Second stage (late) with pulmonary edema and left heart dysfunction or failure.
- Maternal coagulopathy (consumptive) occurs in the majority of cases.
Treatment = Emergency cesarean section is required if uterine hypertonus leads to fetal bradycardia and distress.
What is pre-eclampsia thought to be?
What are the core manifestations? (4)
Levels of TXA2 and Prostacyclin?
In preeclampsia, there is an elevation in thromboxane A2 levels and a decrease in prostacyclin levels leading to a primarily vasoconstricted state.
Preeclampsia is characterized by global vascular hyperreactivity
- intravascular volume depletion
- high systemic vascular resistance
- uterine vasoconstriction of the myometrium
- Decreased uterine and placental blood flow
In anti-phospholipid syndrome, what are the typical coagulation labs showing?
- PT is normal 2. aPTT is prolonged (elevated) - which is paradoxical
Carboprost
What is the full name?
Generic name?
Class?
Mechanism?
Indications?
Side Effects and contraindications?
Carboprost Tromethamine aka 15-methyl prostaglandin F2 alpha aka “Hemabate”
Class: Uterotonic (Stimulates uterine contraction)
Mechanism: - Increase in myometrial free calcium concentration
Indications:
- Uterine Atony
- Need to perform Internal Podalic Version
Contraindications:
- Pulmonary Hypertension
- Reactive airway disease (Asthma/COPD)
- Increased intrapulmonary shunt fraction
- Hypoxemia
What is the preferred anesthetic for a patient undergoing a cerclage?
Spinal Physiology:
Cervix → T10-L1 dermatomes (Ask OB attending) Vagina and Perineum → S2-S4 dermatomes
Indications: Spinal anesthesia with hyperbaric solution is the most appropriate anesthetic for a pregnant patient undergoing cervical cerclage as this method provides adequate sacral coverage for the mother without endangering the fetus.
Avoid general due to:
- Potential hemodynamic changes and placental insufficiency
- Coughing on extubation would worsen prolapse of membranes
- Long acting opiates (D/C same day)
- Avoid Paracervical block (bradycardia)
- Avoid pudendal block (spinal better)
- Cervical cerclage involves suturing the cervix close to treat cervical incompetence.
What are some pharmacological characteristics of drugs that involve placental transfer?
Drug characteristics that facilitate placental transfer include:
- small size (< 500 Dalton’s)
- nonionized/lipid soluble
- poorly protein bound
- high maternal concentration.
Drugs that undergo ion trapping (most importantly local anesthetics) can accumulate more quickly in the setting of fetal acidosis.
When would a paracervical block be indicated?
- What is the downside to a paracervical block?
When would a pudendal nerve block be indicated?
Paracervical Block Indications:
- Analgesia for the 1st stage of labor especially cervical dilation.
- Side effects: High rate of fetal bradycardia. The rate of fetal bradycardia is increased if fetal acidosis is present.
Pudendal Nerve Block Indications:
- Analgesia for the 2nd stage of labor.
- Mechanism: By blocking the pudendal nerve vaginal and perineal distention pain is blocked.
Fetal heart rate variability is primarily determined by what?
Parasympathetic tone of a fetus and is decreased during periods of CNS depression.
Why doesn’t Bupivicaine doesn’t readily cross the placenta?
Bupivacaine does not readily cross the placenta due to:
- its high protein binding
- high pKa of 8.1.
The latter results in a greater concentration of ionized drug which does not easily cross the placenta.
What is the benefits of elective caesarian section compared to vaginal deliveries
- Uterine Rupture 2. Hemorrhage
Discuss the cardiac output changes throughout pregnancy, delivery and post-partum?
Maternal cardiac output progressively increases during
pregnancy and throughout labor, reaching its peak
immediately following delivery (2.5x prepregnancy values or increase 150%).
Cardiac output then quickly declines postpartum and begins to approach prepregnant values by two weeks postpartum.
Stroke volume is the major change, not HR
How does renal physiology change in pregnancy?
How do the labs change?
What is the most common pre-renal and post-renal etiologies in pregnancy?
A serum creatinine concentration:
Greater than 0.8 mg/dL
Blood urea nitrogen concentration greater than 13 mg/dL (which are normal values for the nonpregnant patient) suggest renal insufficiency in the pregnant woman.
Creatinine clearance increases to 150-200 ml/min from 120 ml/min
Prerenal Etiologies:
- Hyperemesis Gravidarum
- Hemorrhage
Postrenal Etiologies:
- Nephrolithiasis
- Ureteral obstruction from gravid uterus
Which of the following changes occurring during pregnancy increases the risk for deep vein thrombosis?
Fibrinogen
A coded pregnant woman after 2 rounds of CPR does not have ROSC, what is your next step?
Delivery Caesarian section to get baby out
Cesarean delivery in the context of maternal cardiac arrest (peri-mortem cesarean delivery [PMCD]) should be strongly considered for every mother in whom return of spontaneous circulation has not been achieved after ~4 minutes of resuscitative efforts (Class IIa; Level of Evidence C).
Compressions done in supine position pushing uterus out of the way. (to the left)
What is the rate of CPR in a neonate?
Chest compressions should be performed in a 3:1 ratio with ventilation at a rate of 120 events per minute (i.e. 90 chest compressions and 30 breaths total per minute), and full chest recoil should be allowed after each compression.
This should continue until the neonate’s heart rate is > 60 bpm.
What is the dose of epinephrine you should use for a neonate in a code?
10-30 mcg/kg q3-5 minutes
Use 1:10,000 concentration of epinephrine
What is the recommended anesthetic for cervical dilation with bulging membranes that needs rescue cerclage placement?
Rescue = General
Prophylaxis = Neuraxial
Prophylactic cervical cerclage is usually performed under neuraxial anesthesia. When cervical dilation and bulging membranes are present, general anesthesia may be preferable if acceptable to the patient. In the absence of studies showing fetal outcomes, no technique is contraindicated, however, general anesthesia has the advantage of causing uterine relaxation which facilitates replacement of membranes.
What are some RF for breech presentation?
Mother:
Multiparty, multiple gestations, hydramnios, previous breech delivery, preterm gestation, oligohydramnios,
Baby: macrosomi, hydrocephalus, anencephaly,
Anatomy: pelvic tumors, uterine anomalies, pelvic contracture, cornual-fundal placenta, and placenta previa.
How do the labs in DIC in pregnancy appear?
Coags, FDP, D-Dimer, Fibrinogen, Anti-thrombin III?
Labs:
Increased PT
Increased aPTT
Increased fibrin degradation products
Increased D-Dimer
Decreased fibrinogen
Decreased antithrombin III
What is the RF for PDPH?
What are some S/S? (Classic one)
Treatment?
Signs/Symptoms
Fronto-occipital with radiation to the neck
CN symptoms
Worse with changes in position - Worse with upright; Relieved when lying flat
24-48 hours following dural puncture
Persists for months to years
Pathophysiology: Debated - Leakage of CSF initiates the syndrome
RF:
Young women (F>M), less likely in old
Thin women > Obese women
Pregnant > Not
Previous history of PDPH
Epidural needle > Spinal needle (Pencil point Whitacre needle; Sprotte also used)
Using air for Loss of resistance technique
Treatment = Blood Patch
What are the risk factors for uterine rupture?
Prior uterine surgery (upper segment scar >> lower segment scar)
Uterine hypercontractility
Oxytocin use
Prostaglandin use
Prolonged labor
Dystocia
Multiparity
Multiple gestations
Congenital uterine anomalies
Polyhydramnios
Trauma
What are the risk factors for pre-term labor?
Previous Preterm delivery
Non-Hispanic Black Race
Multiple gestations
Extremes of age
Low socioeconomic status
Low Prepregnancy BMI
Abnormal uterine anatomy
Abnormal cervical anatomy
Trauma
Abdominal surgery during pregnancy
Tobacco & Substance abuse
What is the most sensitive sign for uterine rupture?
Fetal Distress (Bradycardia, Decelerations)
What is the major disadvantage of paracervical nerve block?
Fetal Bradycardia and therefore:
- Fetal Oxygenation
- Fetal Acidosis
What is the APGAR scoring system?
0 1 2
Skin color
- Cyanotic
- Acrocyanotic (pink chest, cyanotic extremities)
- Pink
Heart rate
- Absent
- < 100 bpm
- >100
Reflex irritability
- NONE
- Grimace +/- feeble cry when stimulated
- ACTIVE
Muscle tone
- Absent
- Limp Some extremity flexion
- ACTIVE
Breathing
- Absent
- Weak, irregular, slow, shallow, or gasping
- Strong
What is the major mechanism of increase in maternal blood volume?
By what % does this increase?
An increase of up to 45% of maternal blood volume is seen during pregnancy.
This effect occurs early within pregnancy and is due to sodium retention via the renin-angiotensin system.
Which of the following is the optimum rostral level of sensory block when neuraxial anesthesia is used for a cesarean delivery?
Adequate neuraxial anesthesia for a cesarean section is best achieved through sensory blockade of the T4-S4 dermatomes.
What is the preferred refersal agent for reversal in a pregnant patient?
Why is this?
For this reason, a combination of neostigmine and atropine rather than neostigmine and glycopyrrolate may be considered for reversal of nondepolarizing neuromuscular blockers in pregnant patients to minimize the risk of fetal bradycardia.
