Obstetrics Flashcards
This deck covers Chapters 178-182 in Rosens, compromising all of obstetrics.
What is the mechanism of action of methotrexate (MTX)?
What are the 6 requirements for MTX in ectopic pregnancy?
What are 3 contraindications to using MTX?
Mechanism
- Folic acid inhibitor which blocks nucleic acid synthesis
Indications
- Hemodynamically stable
- No fetal heart tones
- No evidence of rupture
- Small (< 3.5 cm)
- β-hCG < 5,000
- Good follow-up (reliable)
Contraindications
- Leukopenia
- Thrombocytopenia
- Hepatic disease
- Renal disease
What are the 6 steps in the emergency management of umbilical cord prolapse?
- Elevate the presenting part off the cord
- Place mom in knee-to-chest position
* Alternatively: On all fours - Infuse 500 mL NS into bladder & clamp Foley
* This elevates the presenting part - DO NOT reduce the cord
* Unless no surgical alternative and delivery is happening no matter what - Cover cord with wet gauze + minimize manipulation
- Facilitate crash C-section
Outline the management of severe preeclampsia and eclampsia
- Obstetrics consult
- BP control <160/105
* Labetalol 20 mg IV
* Hydralazine 10 mg IV - Magnesium 4g IV over 15 min then 2 g/hr
* Stop if:
* Areflexia
* RR depression
* UO <25 cc/hr
* Contraindications
* Hypocalcemia
* Renal failure
* Myasthenia gravis
* Reverse with Calcium gluconate
List 6 risk factors for miscarriage
- Extremes of age
- Previous miscarriage
- Smoking
- Cocaine
- Infections
- Chromosomal abnormalities
- Fibroids
- Antiphospholipid Syndrome
- Uterine scarring
- Hx of vaginal bleeding
- Incompetent cervix
Outline your management of PPH
Tone
- Uterine massage
- Oxytocin 20-40 U in 1L NS over 1h (or 10 U IM)
- Methylergonovine 0.2 mg IM Q2-4H
- Carboprost (Hemabate) 0.25 mg IM Q15min x8
- Misoprostol (Cytotec) 1 mg PR
Tissue
- Ensure no tissue in cervix; patient may need D&C
Trauma
- Look for lacerations
Thrombin
- Treat coagulopathies (consider TXA, Vit K, FFP etc.)
Other
- Uterine packing (can soak gauze in thrombin)
- Pelvic vessel embolization (speak to IR)
- Hysterectomy
List 6 warning signs for the development of frank eclampsia
- Headache
- Nausea + vomiting
- Visual disturbances
- MAP > 160
- Elevated AST, LDH, Uric acid
- Hyperreflexia
Your department’s US is broken. Who can get follow up in 24-48 hours for a T1 bleed?
Indications for U/S within 48 hours (not in ED)
- Minimal pain
- Minimal bleeding
- Reliable (will RTED if worse)
- No strong risk factors for ectopic
- No big signs of ectopic (unilateral pain, tenderness, mass)
What is the most sensitive way to diagnose placental abruption?
Fetal monitoring
How do you diagnose PE in pregnancy?
YEARS Algorithm
- Clinical symptoms of DVT?
- PE most likely?
- Hemoptysis?
If none of above, D-dimer <1000 = negative
If one of above, D-dimer <500 = negative
If any above and D-dimer >500 = CTPE
Results: CT pulmonary angiography was avoided in 65% of patients who began the study in the first trimester and in 32% who began the study in the third trimester.
What age of gestation do you consider tocolytics?
Why do we use tocolytics?
What are contraindications to tocolytics?
What agents are commonly used as tocolytics?
Indication
- Women 24-32 weeks of gestation
- Allows delay of labour to mature lungs more
Contraindications
- Chorioamnionitis
- Placental abruption (severe)
- Fetal demise
- Severe uncontrolled HTN/pre-eclampsia (severe)
- >34 weeks
Tocolytics
- Indomethacin (24-32 weeks)
- After 32 weeks, concern about PDA closure
- Nifedipine (32-34 weeks)
- If any contraindication to indomethacin as well
- Magnesium
Why would a pulmonary embolism or DVT be difficult to diagnose in pregnancy?
Challenges with PE diagnosis
- Increased baseline RR (physiologic)
- Dyspnea of pregnancy (physiologic)
- Increased baseline HR (physiologic)
- Radiation concerns (PE only)
- D-dimer will be elevated
- Venous pooling in LE = pain + swelling (physiologic)
Define:
- Gestational HTN
- Chronic HTN
- Preeclampsia
- Eclampsia
Gestational HTN
- BP 140/90 >20 weeks that is new
Chronic HTN
- BP 140/90 <20 weeks or pre-existing HTN
Pre-eclampsia
- HTN 140/90 + Proteinuria (0.3 g/24h)
- Severe defined as any end-organ dysfunction
Eclampsia
- Preeclampsia and seizure or coma
What is the criteria for ultrasound +IUP?
- Bladder/Uterine Juxtaposition
- Myometrial Mantle >8 mm
- Fetal Pole or Yolk sac
- Gestational Sac
Describe Leopold’s maneuvers
1st Leopold Maneuver
- What fetal part occupies the fundus
2nd Leopold Maneuver
- The position of the fetal back
3rd Leopold Maneuver
- What fetal part lies over the pelvic inlet
4th Leopold Maneuver
- Position of the cephalic prominence
What is the earliest hCG can be detected in pregnancy?
When does it peak? Give a value.
- hCG detected at 6 – 8 days after conception
- hCG peaks at 7 – 10 weeks of pregnancy
- Mean value 50,000 mIU/mL (20,000 – 200,000)
How can you estimate gestational age using your exam?
Umbilicus is 20 weeks
Every cm above it is + 1 week
Outline your management of shoulder dystocia
HELPER
- Call for Help
- Empty the bladder/Episiotomy
- Lift legs/Flex hips (McRoberts)
- Pubic (suprapubic) pressure
- Enter the vag: Woods’ Corkscrew
- Reach for posterior shoulder
- Break clavicle
- Push baby into uterus for crash C-section
- Cut pubic symphysis
Concerning transvaginal ultrasonography (TVUS):
A. What is the discriminatory zone?
B. At what β-hCG should you see a yolk sac?
C. At what β-hCG should you see a fetal pole?
D. At what β-hCG should you see fetal heart activity?
Discriminatory zone
- BhCG level when you can reliably see a gestational sac
- TVUS : BhCG 1500
- TAUS: BhCG 6000
Yolk Sac
- 6 weeks and BhCG 2500
Fetal Pole
- 7 weeks and BhCG 5000
Fetal Heart Activity
- 6-7 weeks and BhCG 7000
List 8 physiologic changes in pregnancy
Cardiovascular
- Increased CO
- Increased blood volume
- Increased resting HR
- Decreased SVR / BP
- Increased venous pooling in LE
Pulmonary
- Increased RR (decreased PCO2)
- Decreased FRC
- Decreased VT
- Increased minute ventilation
GI
- Decreased gastric motility (aspiration)
- Decreased LES tone (aspiration)
- Increased ALP
Renal
- Increased RBF
- Increased GFR
- Decreased BUN/Cr
MSK
- Increased ligament laxity
Hematologic
- Increased WBC
- Increased HgB
- Decreased HCT
- Hypercoagulable state
What are the 4 stages of labor?
Stage 1
- From labour onset to maximum cervical dilation
- Has latent phase and active phase, varying timing
- Multiparous women hit active phase earlier
Stage 2
- From maximum cervical dilation to fetal expulsion
Stage 3
- From fetal expulsion to placental expulsion
Stage 4
- The first hour after placental expulsion
- Uterine contraction happens here