Hypertensive Disorders in Pregnancy - Sheiner

Question 1

What is the definition of hypertension during pregnancy?

What are the different types?

Answer 1

Sustained BP of 140/90 or greater: at least 2 measurements taken in an interval of every 6 hours (when seated and relaxed)

• Chronic hypertension
• Before 20 weeks or beyond 6 weeks postpartum
• Gestational Hypertesion
• In second half of pregnancy
• No proteinuria
• Monitor before 37 weeks, then deliver

-Preeclampsia
Eclampsia

-Super Imposed Preeclampsia (chronic HTN + preeclampsia)

Question 2

What are the features/consequences of preeclampsia?

Answer 2

Hypertension with proteinuria (>300mg/day) after the second half of pregnancy

May have other evidence of end-organ disease:

-Epigastric/RUQ pain (liver edema)

Hematologic effects/Laboratory changes
-HELLP
He-hemolysis (anemia)
EL-elevated liver enzymes (LFTs 2x normal)
LP-low platelets (thrombocytopenia <100,000)
Volume contraction
Elevated hematocrit

• *Neurologic:**
• Visual changes (blood or blurry vision)
• Seizures-eclampsia (but rule out epilepsy)
• Headache
• Cerebral edema
• Hyper-reflexia (clonus, not indicative of severity)
• *Cardiovascular effects:**
• (Persistent) Hypertension (chronic if after 6 weeks after delivery)
• Increased cardiac output
• Increased systemic vascular resistance
• Hypovolemia (despite edema)
• Central Edema (look at the nose, eyes and fingers)
• DIC (usually only with placenta abruptia)
• *Renal effects:**
• Oliguria (watch for shock at <25cc/h, increase after surgery normal)
• Decreased glomerular filtration rate
• Increased BUN/creatinine
• Proteinuria
• Acute tubular necrosis
• Complicates magnesium treatment
• *Pulmonary Effects:**
• Pulmonary embolism/edema (often iatrogenic from IV, avoid overhydration, restric fluids and administer lasix if necessary at lose dose)
• Capillary leak
• Reduced colloid osmotic pressure
• *Fetal Effects:**
• Intrauterine growth restriction (IUGR- if separate from HTN can tx conservatively)
• Increased perinatal morbidity
• Placental abruption
• Oligohydramnios
• Fetal distress

Question 3

What is the mechanism/etiology of preeclampsia?

What is the ultimate cure?

Answer 3

Capillary leakage from inappropriate invasion of trophoblasts from the placenta into spiral arteries of the uterus

Also present in molar pregnancies (early onset)

Higher risk in multiple gestations (more placenta)

High genetic components

May have immune/inflammatory component

Nutrition/obesity component

Delivery the placenta (baby)

Question 4

What are the classifications and characteristics of severe eclampsia?

Answer 4

BP > 160 systolic or >110 diastolic
5 grams of protein in 24 hour urine (severe proteinuria)
Oliguria
Cerebral or visual distrubances (and headaches)
Pulmonary edema or cyanosis
Epigastric or RUQ pain
Impaired liver function (ALT and AST)
Thrombocytopenia
IUGR (intrauterine growth restriction)
Decreased AFV (amniotic fluid volume)

Crises are associated with hypovolemia
Clinical assessment of hydration is inaccurate
Unprotected vascular beds are at risk, eg, uterine

Question 5

What are the risk factors for preeclampsia?

Answer 5

Family (or personal) history of PIH 5:1
Diabetes mellitus 2:1
Twin gestation 4:1
Antiphospholipid syndrome 10:1
-Lupus/APLA/CT disorder
Renal disease (can be superimposed or worsening) 20:1
Chronic hypertension (superimposed) 10:1
African American 1.5:1
Age > 40 or <20 3:1
Nulliparity 3:1
Obesity: linear

Question 6

What are methods of prevention of preeclampsia?

Answer 6

Low dose ASA in high risk but ineffective in patients at low risk
Calcium supplementation is ineffective (2.0 g of calcium gluconate per day)- may reduce in high risk

No compelling evidence that either are harmful
Recent study done with antioxidant (1,000mg VitC and 400mg VitE).

Question 7

How is preeclampsia managed?

Answer 7

The ultimate cure is delivery
Assess gestational age (usually OK b/c 3rd trimester)
Fetal well-being
Laboratory assessment
Rule out severe disease
-Check BP to rule out epilepsy
Assess cervix:
-Bishop Criteria (can be increased by mechanical dilation and prostaglandins)
1. Effacement
2. Dilatation
3. Consistency
4. Position (A/P)
5. Station of fetal presenting part
-If unfavorable, consider cesarea, if favorable, give oxytocin

Criteria for Treatment
Diastolic BP > 105-110
Systolic BP > 200
Avoid rapid reduction in BP
Do not attempt to normalize BP (can cause placenta abruptia)
Goal is DBP < 105 not < 90
May precipitate fetal distress

Question 8

What medications are used for preeclampsia/eclampsia?

Answer 8

Seizure prophylaxis:

Magnesium but steroids first for premature fetus (unless unstable)

• Careful monitoring by urine catheter
• Not for hypertension, works as anticongulsant and blocks neuromuscular conduction
• Treats hypovolemia
• Overdose causes paralysis (diminshed deep tendon reflexes- DTRs, altered sensation)
• Narrow therapeutic window
• Antidote: calcium gluconate

Alternate Anticonvulsants:

• Diazepam 5-10 mg IV
• Sodium Amytal 100 mg IV
• Pentobarbital 125 mg IV
• Dilantin 500-1000 mg IV infusion

After the seizure:
Assess labs, effect delivery (but there is time for preparation)

Question 9

What medications are used to treat gestational hypertension?

Answer 9

Use any cautiously

First line: Hydralazine

• Peripheral vasodilator
• Side effects: headache (may have preexisted), flushing, tachycardia, lupus like symptoms

Labetalol

• Alpha/beta blocker
• Side effect: hypotension

Nifedipine
-Calcium channel blocker
Side effects: chest pain, headache, tachycardia

Clonidine

• Alpha agonist
• Avoid rapid withdrawal

Nitroprusside

• Direct vasodilator
• Side effects: Cyanide accumulation and hypotension