Flashcards in Lecture 14 Hypertensive disorders of pregnancy Deck (19):
Complications of pregnancy-associated hypertensive disorders
1. Uteroplacental insufficiency.
2. Premature birth.
3. IUGR, oligohydramnios, and fetal demise.
Diagnosis of hypertension
1. Requires 2 blood pressure readings, taken at least 4 hours apart. (Obstetric client: BP should be taken after 20 weeks of gestation.)
2. A systolic blood pressure greater than 140 mm Hg *OR* a diastolic blood pressure greater than 90 mm Hg.
Lactate dehydrogenase (LDH)
An enzyme released as a result of hemolysis; elevated in preeclampsia.
H - Hemolysis (AEB decreased RBCs and platelets, hyperbilirubinemia, and elevated lactate dehydrogenase)
EL - Elevated Liver enzymes (AST and ALT)
LP - Low Platelets (less than 100,000)
A *laboratory diagnosis* (not a separate illness) for a variant of severe preeclampsia that involves *hepatic dysfunction*.
The onset of hypertension *without proteinuria* or other systemic findings diagnostic of preeclampsia after week 20 of pregnancy.
A pregnancy-specific condition in which hypertension *and* proteinuria develop *after 20 weeks* of gestation in a woman who previously had neither condition. Can also develop in the early postpartum period.
The onset of *seizure activity* or coma in a woman with preeclampsia who has no history of preexisting pathology that can result in seizure activity.
Preeclampsia with *preexisting* chronic hypertension (difficult to diagnose).
Cause and resolution of preeclampsia
1. Believed to be the result of *disruptions in placental perfusion* (placental ischemia) and *endothelial cell dysfunction*.
2. Disease is linked to the placenta; therefore it begins to resolve after the placenta has been expelled.
Renal changes in preeclampsia
1. Proteinuria - primarily *albumin*.
2. Decreased GFR, oliguria, and elevated serum creatinine - due to decreased renal perfusion.
3. Uric acid clearance is decreased; *serum* uric acid levels increase.
4. Sodium and water are retained.
Neurologic changes in preeclampsia
1. *Cerebral edema* causes increased irritability of the CNS - hyperreflexia, positive ankle clonus, headaches, seizures.
2. Visual disturbances (e.g., scotoma - dim vision or blind or dark spots in the visual field) occur due to retinal arteriolar spasm.
Medications used to treat preeclampsia
1. Daily low-dose aspirin (60 to 80 mg) beginning late in the 1st trimester can help high risk women.
2. Antihypertensives (labetalol, hydralazine, methyldopa, nifedipine) are useful for severe hypertension.
3. Magnesium sulfate is used for *seizure prevention* but *not* as an antihypertensive agent.
Deep tendon reflexes (DTRs)
1. Reflect the balance between the cerebral cortex and the spinal cord.
2. *Normal finding = 2+ response.*
3. Clonus = hyperactive reflexes; observed in the ankle by sharply dorsiflexing the patient's foot and watching for oscillations as the foot drops to the plantar-flexed position.
Magnesium sulfate (seizure prevention)
1. Drug of choice for the prevention/treatment of *eclampsia* - decreases hyperreflexia and minimizes the risk of seizure activity.
2. A therapeutic serum magnesium level of *4 to 7 mEq/L* is maintained.
3. Antitode for magnesium sulfate toxicity: *Calcium gluconate*.
4. Nursing considerations: Maintain a *quiet, darkened environment* to reduce stimuli; *assess DTRs hourly*; regularly assess urine output and FHR tracing. *Notify provider of respiratory less than 12/min.*
5. Side effects: A feeling of warmth, flushing, diaphoresis, burning at the IV site, sedation, nausea.
Clinical signs that demonstrate resolution of preeclampsia include _
Diuresis and decreased edema.
The client has been on magnesium sulfate for 20 hours for the treatment of preeclampsia. She just delivered a viable infant girl 30 minutes ago. What uterine findings does the nurse expect to observe or assess in this client?
Boggy uterus with heavy lochia flow. [High serum levels of magnesium can cause a relaxation of smooth muscle such as the uterus. Because of this tocolytic effect, the client will most likely have a boggy uterus with increased amounts of bleeding. All women experience uterine bleeding in the postpartum period, especially those who have received magnesium therapy. Rather than scant lochial flow, however, this client will most likely have a heavy flow attributable to the relaxation of the uterine wall caused by magnesium administration.]
The client is being induced in response to worsening preeclampsia. She is also receiving magnesium sulfate. It appears that her labor has not become active, despite several hours of oxytocin administration. She asks the nurse, “Why is this taking so long?” What is the nurse’s most appropriate response?
“The magnesium is relaxing your uterus and competing with the oxytocin. It may increase the duration of your labor.” [Because magnesium sulfate is a tocolytic agent, its use may increase the duration of labor. The amount of oxytocin needed to stimulate labor may be more than that needed for the woman who is not receiving magnesium sulfate.]
Which intervention is most important when planning care for a client with severe gestational hypertension?
Induction of labor is likely, as near term as possible. [By 34 weeks of gestation, the risk of continuing the pregnancy may be considered greater than the risks of a preterm birth.]