OB/GYN Emergencies Flashcards
Criteria for mild preeclampsia?
Systolic blood pressure _> 140mm Hg or diastolic blood pressure _> 90mm Hg
AND
Proteinuria (> 0.3 grams in 24 hr collection)
AND
> 20 wk gestations
AND
No other systemic signs or sx
Criteria for severe preeclampsia
Blood pressure _> 160 mm Hg systolic or _> 110mm Hg diastolic measured on two occasions at least 6 hrs apart with the pt at rest
AND
Visual disturbances or mental status disturbances OR Pulmonary edema or cyanosis OR Epigastric or RUQ pain; abnormal LFTs OR Thrombocytopenia OR Oliguria (<500 mL in 24 hrs) OR Proteinuria (_>5g in 24hr collection or _>3+ on two random urine samples collection at least 4hrs apart
Difference between chronic HTN in pregnancy VS Gestational HTN
Chronic HTN in preg is BP that is _>140mm Hg systolic or _>90mm Hg diastolic, before 20 weeks gestation or persistent longer than 12 weeks after delivery.
Gestational HTN is BP _>160mm Hg systolic or _>90mm Hg diastolic after 20wks gestation or in the immediate postpartum period w/o proteinuria.
1st and 2nd line tx of chronic HTN in pregnancy?
What can be added if not controlled by 1st or 2nd line tx?
- Labetalol
Starting dose: 100mg po, bid
Maintenance: 200-400mg po, bid - Methyldopa
Starting dose: 250mg q6h, titrate up to desired blood pressure.
Maintenance: 500mg-3,000mg, divided in 2-4 daily doses, max 3,000mg
Nifedipine XL (can be added if not controlled with labetalol or methyldopa) Starting dose: 30mg po, qd Can increase up to 120mg qd
Which BP meds are contraindicated in pregnancy and why?
ACE inhibitors and ARBs are contra indicated because of teratogenic effects on fetal scalp, lungs, and kidneys.
What is the cause of preeclampsia?
Cause is unknown but the histologic hallmark lesion of preeclampsia is acute atherosis of decidual arteries (arteries in the endometrium). Atherosis and thrombosis are thought to lead to placental ischemia and infarctions. Poor placental perfusion is presumed to lead to the formation of free radicals, to oxidative stress, and to inflammatory responses that may influence the mechanistic development of preeclampsia.
What is the definitive resolution of preeclampsia?
Delivery
How does preeclampsia affect gestation?
It is associated with intrauterine growth retardation, premature labor, low birth weight, abrupt placentae, and future risk of maternal cardiovascular disease.
What increases the chances of recurrence of preeclampsia?
Preeclampsia during initial pregnancy
Risk factors for preeclampsia
Maternal age >40 years old HTN DM Renal dz Collagen vascular dz Multiple gestation
What therapy can prevent preeclampsia and it’s complications?
Low-dose aspirin therapy
What is HELLP syndrome?
Clinical variant of preeclampsia. It is associated with:
- Hemolysis (w/ microangiopathic blood smear. Schistocytes)
- Elevated liver enzymes (total bilirubin >1.2 mg/dL, AST >2x upper limit)
- Low platelet count (<100,000 cells/microL)
What is most common clinical presentation for HELLP syndrome?
Abdominal pain and tenderness in the midepigastrium, RUQ, or below the sternum.
What is the time frame that a pregnant women with abdominal pain should be evaluated for HELLP syndrome?
> 20 wks gestation to 7 days postpartum
What unique finding would you have in a pt with HELLP syndrome on a blood smear?
Schistocytes
What are the complications of severe preeclampsia, HELLP syndrome, and eclampsia?
- Disseminated intravascular coagulopathy (DIC)
- Spontaneous hepatic and splenic hemorrhage
- End organ failure
- Abruptio placentae
- Intracranial bleeding
- Maternal death
- Fetal death
Tx for mild preeclampsia
- Out patient management is an option after consult with OB/GYN
- Should arrange frequent clinical and laboratory evaluation and close fetal surveillance
When should someone with mild preeclampsia be immediately reevaluated?
When presenting w/ sx of HA, scintillating scotomata, other visual changes, abdominal pain, vaginal bleeding, decreased fetal movement
Tx for severe preeclampsia (BP >160 mm Hg)
- Tx with HTN meds (labetalol, hydralazine, and nifedipine)
- IV magnesium sulfate (for seizures)
- Consult with OB/GYN
- Probable admission
Initial management of HELLP syndrome?
Similar to severe preeclampsia and eclampsia:
- IV magnesium
- BP control
- Hospital admission
- Correct coagulopathy
What is eclampsia?
The development of new-onset seizures superimposed upon preeclampsia (also can be encephalopathy or coma)
*Between >20wks gestation to <4wks postpartum.
*Can also present with just seizures w/o HTN or proteinuria
What is treatment of eclampsia?
- Tx seizures (mag sulfate)
- Tx HTN (labetalol, hydralazine, nifedipine)
- Tx coagulopathy
- Emergent consult with OB/GYN for urgent delivery of fetus
How do you treat seizures with magnesium sulfate? Dosing, etc.
What about pts with renal insufficiency?
- 4-6g IV in 100-mL aliquot given over 20-30 mins
- Followed by infusion of 2g/hr for at least 24 hrs
*Mag sulfate is excreted renally. In Pt with renal insufficiency: reduce to 2g IV bolus, then obtain serum mag level before increasing dose.
Main side effects of high levels of magnesium
Flushing Diaphoresis Hypothermia Hypotension Flaccid paralysis Respiratory depression
Sx of magnesium toxicity
Diminished patellar reflexes
Respiratory rate slows
Labetalol: MOA, onset of action, dosage
MOA: selective alpha and nonselective beta antagonist
Onset: 5 mins
Dosage: 20mg IV, then 40-80 IV every 10 mins prn (max, 300mg); IV infusion 1-2mg/min titrated
What are some benefits using labetalol vs hydralazine?
There is less hypotension and reflex tachycardia than hydralazine. Higher doses cause neonatal hypoglycemia. Longer use associated with fetal growth restriction.
Hydralazine: MOA, onset of action, dosage
MOA: arterial vasodilator
Onset: 20 mins
Dosage: 5mg IV or 10mg IM, repeat at 20min intervals; consider other drug if no response at maximum of 20mg IV or 30mg IM
What are some special considerations when using hydralazine for maternal HTN?
Maternal hypotension, fetal distress; must wait 20mins for response between IV doses
Nifedipine: MOA, onset of action, dosage
MOA: Ca channel antagonist (blocker)
Onset: 10-20 mins
Dosage: 10mg po, repeat in 30 mins if necessary
Special considerations for nifedipine
FDA does not approve short-acting nifedipine for tx of HTN
