ch. 27 hypertensive disorders Flashcards
major cause of maternal and perinatal morbidity and mortality
hypertensive disorders
3 most common types of hypertensive disorders occurring in pregnancy
- gestational hypertension
- preeclampsia
- chronic hypertension
gestational hypertension (what, parameters, extra)
- development of hypertension after WEEK 20 of pregnancy in a woman w/ previously normal BP
- systolic bp: >/= 140
- diastolic bp: >/= 90
- resolves after giving birth, although it may require 6-12 months to do so
preeclampsia (what, can develop) (if no ______, 7)
pregnancy specific condition in which hypertension and proteinuria develops after 20 weeks of gestation in a woman who previously had neither condition
- can develop for the first time during postpartum period (6-8 wks)
in the absence of proteinuria, preeclampsia may be defined as hypertension along with the following:
- thrombocytopenia (decreased PLT)
- impaired liver function (increase AST/ALT)
- persistent RUQ or epigastric pain (d/t liver swelling, hematoma, oliguria)
- progressive renal insufficiency (renal shut down, increased Cr/BUN)
- pulmonary edema (gen. edema -> pul. edema CHF)
- new onset cerebral symptoms NOT responding to analgesia (headache, dizziness, scotamas, hyperreflexia)
- visual disturbances
eclampsia (5)
seizures onset
- onset of seizure activity or coma in a woman w/ preeclampsia
- no history or preexisting (seizure related) pathology
- occurs in approximately 1 in 2000 to 1 in 3440 births
- incidence usually higher in tertiary referral centers, with multifetal gestation, and in women who did NOT receive prenatal care (29% MI)
- can occur BEFORE/DURING/AFTER birth, many occur more than 48H postpartum
chronic hypertension
- hypertension present before pregnancy or diagnosed before 20 week gestation
chronic hypertension w/ superimposed preeclampsia (what, diagnosis based on (2))
1) women w/ chronic hypertension may develop superimposed preeclampsia
2) diagnosis based on one or both of the following:
- a sudden increase in BP previously well controlled
- new onset or sudden and sustained increase in proteinuria in a women known to have proteinuria before conception or EARLY in pregnancy
preeclampsia etiology (what, occurs in, common risk factors (5), paternal factors, causes)
1) condition unique to human pregnancy
2) occurs in approximately 2-7% of healthy nulliparous pregnancy women
3) common risk factors:
- multifetal gestation
- hx. preeclampsia
- chronic HTN
- preexisting diabetes and/or thrombophilias (blood disorder - sickle cell, thalassiemia minor)
- nulliparity (couldn’t carry past 20 weeks)
4) paternal factors: men who have fathered preeclampsia pregnancy are TWICE as lickely to father another preeclampsia pregnancy with a different woman, regardless of whether the new partner has a history of preeclamptic pregnancy
5) cause of preeclampsia is UNKNOWN
- thought is that preeclampsia is caused by a complex interaction of maladpative cardiovascular and uteroplacental response to pregnancy
preeclampsia pathophysiology (10)
- progressive disorder w/ placenta as the root cause
- begins to resolve after the placenta has been expelled
- spinal arteries in the uterus normally become larger and thicker to handle increased blood volume (50% increase)
- this vascular remodeling does NOT occur or only partially develops in women with preeclampsia and decreased placental perfusion and endothelial dyfunction result
- placental ischemia leads to endothelial cell dysfunction
- generalized vasospasms leads to poor tissue perfusion in all organ systems (increased peripheral resistance and BP, increased endothelial cell permeability)
- reduced kidney perfusion
- plasma colloid osmotic pressure decreases
- decreased liver perfusion
- neurologic complications: cerebral edema, cerebral hemorrhage (stroke), central nervous system irritability
HELLP syndrome (3)
severe case of preeclampsia
H - hemolysis (breakdown of RBC)
E - elevated liver enzymes (EL) (increased AST/ALT)
L - low platelets (LP) (decreased PLT, bleeding out)
- can develop in women who do not have HTN or proteinuria
- specific lab findings are needed to diagnose HELLP syndrome and distinguish it from other serious diseases that share the same s/sx
- perinatal mortality rate ranges from 7.4% - 34% with a maternal mortality rate of approximately 1%
care mgmt: identifying and preventing preeclampsia (3)
- no reliable test or screening tool has been developed
- low dose aspirin (81 mg daily) may help certain high risk women (decreased risk preeclampsia) - start before 16 weeks
- potential biomarkers that can identidy individual women who will develop hypertension during pregnancy is ongoing (CBC, PLT, AST/ALT, Cr/BUN)
care mgmt assessment (6)
- accurate measurement of BP
- assessment of edema, although the presence of edema is no longer included in the definition of preeclampsia (B/L)
- deep tendon reflexes (DTRs)
- assess for hyperactive reflexes (clonus)
- proteinuria: ideally determined by evaluation of a 24 hour urine collection (studies have shown little relationship between the degree of proteinuria in women w/ preeclampsia and pregnancy outcome)
- evaluate s/sx of severe preeclampsia: severe headache (frontal), epigastric pain (heartburn), RUQ pain, visual disturbances (scotoma, photophobia, double vision)
CBC/Cr/BUN
interventions: gestational hypertension and preeclampsia WITHOUT severe features (goals (2), 4)
1) goals:
- ensure maternal safety
- for a women to give birth to a live newborn, that will not require intensive and prolonged neonatal care
2) outpatient mgmt
3) lab evaluations
4) fetal evaluation
5) activity restriction: no evidence that BR improves outcomes
interventions: gestational hypertension and preeclampsia WITH severe features (goals, expectant mgmt (2), intrapartum care( 4))
goals:
- ensure maternal safety and formulate a plan for delivery
1) expectant mgmt:
- women who are less than 34 weeks of gestation and have NO indication for giving birth immediately may be candidates (increased chance survival)
- hospitalized care from interprofessional team, including a perinatologist, antihypertensive meds, and corticosteroids to enhance fetal lung maturity
2) intrapartum care:
- continuous FHR and uterine contraction monitoring
- BR w/ side rails up (padded side rails)
- quiet, darkened environment
- assessed for signs of placental abruption (d/t increased BP)
interventions: magnesium sulfate (what, route, initial loading dose, effect, medication alert)
- medication of choice for preventing and treating seizure activity (eclampsia)
- relieves muscles and decreases risk for seizures
- administered IVBP
- initial loading dose: 4-6gms, then continuous 1-2gms
- has little effect on maternal BP when administered in this fashion
- medication alert: high serum levels of magnesium can cause relaxation of smooth muscle, such as the uterus
TIP:
- calcium contracts muscles
- R/R: respiration/reflex
- mg toxicity: decreased resp/reflex
- antidote: calcium gluconate
