Hypertensive Disorders In Pregnancy Flashcards
What are hypertensive Disorders
Hypertensive disorders of pregnancy include chronic hypertension, preeclampsia/eclampsia, gestational hypertension, and hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome.
DEFINITION HPT
HYPERTENSION
A diastolic blood pressure ≥ 90 mmHg but < 110 mmHg on two occasions, taken at least 2 hours apart, or a single diastolic measurement
of ≥ 110 mmHg
AND/OR
A systolic blood pressure ≥ 140 mmHg but <160 mmHg on two occasions, taken at least 2 hours apart, or a single systolic measurement of ≥ 160
mmHg. A raised systolic pressure is indicative of hypertension - even in the absence of a raised diastolic blood pressure.
Acute severe Hypertension
A medical emergency and is defined as a systolic BP ≥ 160 mmHg and/or diastolic BP≥110 mmHg.
Significant proteinuria
The presence of 1+ or more proteinuria on a test strip (dipstick) in a clean catch urine specimen on 2 occasions, at least 2 hours apart. Test for
proteinuria in all antenatal patients using bed side tests.
Hypertension may be accompanied by any of the following:
- The presence of 1+ or more proteinuria on a test strip (dipstick) in a clean catch urine specimen on 2 occasions, at least 2 hours apart.
- Generalized oedema of face, fingers, feet
- Eclamptic fits
- Complications such as HELLP syndrome, pulmonary edema and acute renal failure.
Classification
- Chronic hypertension
- Gestational hypertension
- Preeclampsia
- Eclampsia
Chronic hypertension?
Hypertension that is present before 20 weeks of gestation or if the woman was already taking antihypertensive medication before the pregnancy.
Gestational Hypertension?
New onset of hypertension presenting only after 20 weeks of gestation without significant proteinuria.
Pre-eclampsia?
Pre-eclampsia
Hypertension with significant proteinuria developing for the first time after 20 weeks of gestation.
Pre-eclampsia can also be superimposed on chronic hypertension - evidenced by the new onset of persistent proteinuria in a woman who had an initial diagnosis of chronic hypertension.
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Mild to moderate and preeclampsia?
• Mild to moderate and preeclampsia : a diastolic BP of 90-109 mmHg and/or systolic blood pressures of 140-159 mmHg, with ≥1+ proteinuria; and no organ dysfunction.
Severe pre-eclampsia?
• Severe pre-eclampsia:
○ Acute severe hypertension (diastolic BP of ≥110 mmHg and/or systolic of greater than 160 mm Hg) with ≥1+ proteinuria
OR
○ Hypertension and/or proteinuria (any degree) with signs of organ dysfunction (platelets <100 000/µl; creatinine or liver enzymes (ALT)
more than double the normal values; or neurological signs like persistent headache, visual disturbances and dizziness
Imminent eclampsia?
Symptoms and signs that characterise severe pre-eclamptic women, i.e. severe persistent headache, visual disturbances, epigastric pain, hyper-reflexia, clonus, dizziness and fainting, or vomiting.
Eclampsia?
Generalised tonic-clonic seizures after 20 weeks of pregnancy and within 7 days after delivery, associated with hypertension and proteinuria.
HELLP syndrome
The presence of Haemolysis, Elevated Liver enzymes and Low Platelets, almost always in association with hypertension and proteinuria.
HOW TO TAKE BLOOD PRESSURE IN PREGNANY
- Use correct cuff size (length of 1.5 times the circumference of the arm).
- Use obese cuff (15x33 cm) if the middle upper arm circumference is > 33 cm.
- Patient may sit or lie on her side – never flat on her back!
- Cuff should be on the level of the heart during measurement.
• Measure the diastolic blood pressure at the point where the sounds disappear (Korotkoff phase five). In patients
where the sounds do not disappear, use the point of muffling (Korotkoff phase four).
WOMEN AT RISK FOR THE DEVELOPMENT OF Pre-eclampsia?
ANY pregnant women CAN develop pre-eclampsia. Those most susceptible are:
- Primigravidae, in particular teenagers and elderly primigravidae
- Women of age 35 years and above
- Women with a previous pregnancy complicated by pre-eclampsia
- Women with a previous abruptio placentae or intra-uterine death.
- Women with multiple pregnancies
• Medical complications such as chronic hypertension, renal disorders, diabetes, connective tissue disorders or
antiphospholipid syndrome
• Women who develop oedema in the mid trimester or have excessive weight gain
Pathophysiology of Hypertension in pregnancy
° Weak trophoblast differentiation during the process of endothelial invasion.
°Abnormal development and remodeling of spiral arteries in the deep myometrial tissues.
°Placental hypoperfusion and ischemia
°Cascade of inflammatory events with Placental release of cytokines factors.
°Disrupting the balance of angiogenic factors and including Platelet aggregation
°Systemic endothelial dysfunction
°Decreased renal pressures natriuresis
°Systemic hypertension
Preeclampsia pathophysiology
Defective spiral artery remodeling → placental hypoperfusion → systemic vasoconstriction and endothelial dysfunction → hypertension → proteinuria and/or end-organ damage.
HELPP syndrome pathophysiology
HELLP is an extension of preeclampsia
° May be closely related to atypical hemolytic uremic syndrome
° Endothelial injury with fibrin deposits → thrombotic microangiopathy → microangiopathic hemolytic anemia (MAHA) + liver damage + platelet-activation and consumption → thrombocytopenia + elevated liver enzymes